WSe₂ nanoflowers grown on Ti₃C₂Cl₂ MXene for energy applications and sensing

Abstract

Developing multifunctional materials for energy and sensing is challenging due to demands for high conductivity, catalytic activity, and structural stability. We report a WSe₂/Ti₃C₂Cl₂ hybrid synthesized via one-step solvothermal growth of WSe₂ nanoflowers on Cl-terminated MXene. The strong interface improves electron transport and active site exposure, achieving excellent hydrogen evolution activity with an overpotential of −0.19 V vs RHE at −10 mA cm⁻². The WSe₂-rich hybrid delivers an initial discharge capacity of 1255 mAh g⁻¹ as a lithium-ion battery anode, outperforming its individual components. MXene boosts conductivity, while WSe₂ morphology buffers volume changes. For sensing, the hybrid doubles the H₂O₂ reduction signal of WSe₂ and enables amperometric detection from 1 to 88 μM with a 0.6 μM detection limit. Overall, in situ growth of WSe₂ on MXene offers a scalable route to efficient multifunctional materials.

Introduction

Electrochemistry has garnered significant attention in recent years thanks to its unique ability to combine energy storage, conversion, and sensing technologies, serving as a cost-effective alternative for environmental sustainability¹. The performance of these electrochemical systems relies upon using materials that facilitate electron transfer and enhance the efficiency of the applications. Nevertheless, each electrochemical system has unique requirements that can differentiate the suitability of various materials. High electrical conductivity, good charge transfer kinetics, and large surface area are desirable properties of electrochemical systems^1,2. In contrast, good adsorption, high (electro)catalytic activity, and porosity are more controversial properties that can benefit one application and interfere with the other. This duality highlights the need for multifunctional materials capable of enhancing several electrochemical processes simultaneously, offering a solution to multiple challenges at once. Recent advances in materials design, especially 2D materials like MXenes and transition metal dichalcogenides (TMDs), have opened new possibilities for electrocatalysis, energy storage, and sensing applications^3,4.

In the field of electrocatalytic hydrogen production, the hydrogen evolution reaction (HER) has gained attention as a promising method for sustainable energy conversion^5,6. However, the widespread use of noble metal-based electrocatalysts remains hindered by their high cost and limited abundance. Non-precious alternatives, such as MXenes and TMDs, have shown promise as HER electrocatalysts^7,8,9, though MXenes like Ti₃C₂ have exhibited lower-than-expected HER performance. Despite predictions of high HER activity, Ti₃C₂ MXene has shown a significantly large overpotential in aqueous electrolytes. Specifically, its overpotential is nearly double that of Ti₄N₃ nitride MXene (0.8 V vs. 0.4 V) and is considerably higher than Mo₂C carbide MXene¹⁰. The reason for this has been recently revealed by studying the electrocatalytic HER mechanism with in situ Raman spectroscopy. The analysis of Ti₃C₂ MXene in the HER process revealed a shift in surface terminations from –O to –OH under acidic conditions, resulting from proton adsorption¹¹. This imbalance in protonation and deprotonation at Ti/O sites likely contributes to the high overpotential of Ti₃C₂ MXene during HER. Thus, combining Ti₃C₂ MXene with TMDs, such as tungsten diselenide (WSe₂), is rational to boost their performance¹². WSe₂ has shown great potential in electrocatalytic HER^8,11,13. When solvothermal bottom-up methods produce WSe₂, they can provide materials with increased surface area and abundant defected sites that are highly valuable for electrocatalysis and are in high quantity and the desired polymorph. 1T (metallic) phase is more desirable than the semiconducting (2H) due to the sufficient charge transfer that helps the reaction kinetics^9,14.

Lithium-ion batteries (LIBs) continue to be critical in the development of high-performance energy storage solutions, especially for electric vehicles and portable electronics. However, the demand for higher energy density, longer cycle life, and improved rate capability remains a key challenge^15,16. WSe₂ has shown promise as an anode material due to its high volumetric energy density and efficient lithium-ion diffusion^13,17. However, its application in batteries has been limited to specific configurations, and further research is needed to optimize its integration with other materials. In this context, Ti₃C₂ MXene has demonstrated great promise for energy storage^4,18. Hybridizing MXenes like Ti₃C₂ with TMDs offers an exciting opportunity to combine the high conductivity of MXenes with the electrochemical properties of TMDs to improve battery performance¹⁹.

For sensing applications, particularly in detecting hydrogen peroxide (H₂O₂), advanced materials are needed to improve sensitivity and selectivity. Hydrogen peroxide is crucial in both biological processes and industrial applications, but at high concentrations, it can pose significant health risks^20,21. Ti₃C₂ MXenes, owing to their excellent electrical conductivity and surface functional groups, have also been actively investigated as promising candidates for electrochemical sensors²². As regards sensing, WSe₂ has been involved in gas sensing²³, but its electroanalytical sensing capabilities remain unexplored. Hybrid materials comprising MXenes and TMDs are showing promise for electrochemical sensors²⁴ due to their unique combination of conductivity and catalytic activity, which is especially beneficial for H₂O₂ detection.

MXenes follow the molecular formula M_n+1X_nT_x, where M is an early transition metal, A is a group 13 and 14 element, X is carbon and/or nitrogen, and n = 1–4. MXenes are synthesized by selective etching of the “A” element of the corresponding MAX phase²⁵. This results in a unique 2D material with high conductivity, tunable surface chemistry, and versatility for energy, catalysis, and sensing applications. Over the years, various etching methods have been developed to synthesize MXenes, including traditional hydrofluoric acid (HF)-based etching and, more recently, molten salt (MS).

In this regard, molten salt etching, particularly Lewis acidic molten salt (LAMS) approaches, has emerged as a promising alternative for MXene synthesis due to its ability to produce MXenes with exclusive surface terminations²⁶. For example, etching Ti₃AlC₂ MAX phases with molten CuCl₂, FeCl₂, or ZnCl₂ salts has yielded Cl-terminated MXenes. However, these methods are often associated with challenges such as introducing undesired surface groups during post-synthesis washing (e.g., CuCl₂ due to washing with ammonium persulfate solution)²⁶ or the need for inert storage conditions for highly hygroscopic salts like ZnCl₂²⁷. CdCl₂ has also been used as a molten salt for LAMS, yielding high-quality Cl-terminated MXenes²⁷. However, its toxicity and carcinogenic risks pose serious concerns for large-scale and sustainable synthesis. We propose the use of potassium chloride (KCl) as a co-solvent to address these limitations and reduce reliance on toxic compounds like CdCl₂. It offers practical advantages due to its low cost, wide availability, and ease of handling under ambient conditions. By combining KCl with CdCl₂ in optimized ratios, these Cl-terminated MXenes, with their well-defined surface terminations, provide an ideal scaffold for the in situ growth of functional nanomaterials like TMDs.

In situ growth of the immobilization of 2D materials or nanoparticles supported by conductive substrates is a widely recognized concept^28,29. These substrates provide a structure to support the deposited material and act synergistically to enhance conductivity and charge transfer kinetics. In most electrocatalytic processes, electrical conductivity is one of the most critical factors in achieving good performance. High conductivity can realize very effective energy conversion by reducing the Schottky barrier in the catalyst-electrolyte and catalyst-electrode interfaces, thus facilitating the path that electrons travel and increasing the efficiency of the overall reaction³⁰. Existing studies for hybrids consisting of WSe₂ and Mxene are scarce, involving high-temperature synthetic procedures³¹, electrostatic interactions³², or via simple mixing³³. These hybrids have predominantly been applied to individual applications such as HER and/or supercapacitors^31,34, or gas sensing³². However, to the best of our knowledge, the concept of in situ growth of WSe₂ onto Cl-terminated Ti₃C₂ MXene, designed as a truly multifunctional hybrid capable of addressing HER, lithium-ion batteries, and sensing applications, has not been explored. This underscores the potential of our approach in developing a versatile, multifunctional material.

In this work, we employed a straightforward solvothermal method to achieve the in situ growth of WSe₂ nanoflowers on Ti₃C₂Cl₂ MXene. First, the MXene was synthesized using the LAMS approach, which combined KCl and CdCl₂ to achieve Cl-terminated surfaces. The ratios of WSe₂ to MXene were optimized based on the performance in HER in acidic medium. The hybrid material with the optimal ratio was further explored as an anode for LIBs and an electrocatalyst for the amperometric determination of H₂O₂. The materials were structurally and morphologically characterized by using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM). The strong interaction between the two components due to their immediate contact along with the synergetic effect between the two materials (i) enhance electron flow enabling lower overpotentials to initiate hydrogen production, (ii) attain a higher initial discharge capacity with improved rate capability and cycling stability, resulting in enhanced LIB performance and (iii) exhibit higher cathodic current in the presence of H₂O_2, leading to an electrochemical sensor with improved sensitivity.

Methods

General

Ti₃AlC₂ MAX phase was purchased from Jinzhou Haixin Metal Materials Co., Ltd (China). All the other chemicals, reagents, and solvents were purchased from Sigma–Aldrich and used without further purification.

Synthesis of Ti₃C₂Cl₂ MXene

The Cl-terminated MXenes were synthesized using a modified version of a previously reported procedure³⁵. Briefly, Ti₃AlC₂ MAX phase (3 g) was mixed with CdCl₂ and KCl in varying molar ratios (1:6:2, 1:5:3, 1:3:5, and 1:2:6). The mixture was homogenized using a mortar and pestle, and ground for 10 min. The resulting mixtures were pressed into pellets and placed in alumina crucibles. The reactions were conducted under an inert argon atmosphere (flow rate ≈4 mL/min) in an alumina tube at 700 °C with a dwell time of 24 h, with a heating and cooling rate of 2 °C/min. After the reaction, the MXenes were recovered by dissolving the residues of cadmium metal in concentrated HCl. For this, the solid products, including the alumina crucible, were transferred to a glass beaker, and 200 mL of HCl was added and left overnight to ensure the complete dissolution of excess reactants. The mixture was then centrifuged (3224 rcf, 5 min) and washed with deionized water until the supernatant reached a neutral pH, followed by two additional washes with methanol. Finally, the sample was vacuum-dried at 35 °C for at least 12 h, and the powder was collected for subsequent steps.

Preparation of WSe₂

Tungsten hexacarbonyl (1 mmol) and selenium powder (2 mmol) were dissolved in 30 mL of dimethylformamide (DMF), and the resulting suspension was transferred into a 50 mL Teflon-lined stainless-steel autoclave reactor and heated at 200 °C for 13 h. After the autoclave was cooled to room temperature, the resulting suspension was centrifuged for 30 min. at 10,000 rpm with DMF (2 times), distilled water (3 times), and methanol (3 times).

Preparation of WSe₂/Ti₃C₂Cl₂ MXene with higher WSe₂ content

Tungsten hexacarbonyl (0.5 mmol) and selenium powder (1 mmol), along with 2.5 mg of Ti₃C₂Cl₂ MXene, were dissolved in 30 mL DMF, and the resulting suspension was transferred into a 50 mL Teflon-lined stainless-steel autoclave reactor and heated at 200 °C for 13 h. After the autoclave was cooled to room temperature, the resulting suspension was centrifuged at 10,000 rpm with DMF (2 times), distilled water (3 times), and methanol (3 times). This sample is designated as w-WSe₂/Ti₃C₂Cl₂.

Preparation of WSe₂/Ti₃C₂Cl₂ MXene with higher MXene content

Tungsten hexacarbonyl (0.145 mmol) and selenium powder (0.29 mmol), along with 20 mg of Ti₃C₂Cl₂ MXene, were dissolved in 30 mL DMF, and the resulting suspension was transferred into a 50 mL Teflon-lined stainless-steel autoclave reactor and heated at 200 °C for 13 h. After the autoclave was cooled to room temperature, the resulting suspension was centrifuged at 10,000 rpm with DMF (2 times), distilled water (3 times), and methanol (3 times). This sample is designated as m-WSe₂/Ti₃C₂Cl₂.

Microscopy techniques

The morphology of the analyzed materials was investigated using SEM with a Tescan MAIA-3 Field Emission Gun Scanning Electron Microscope (FEG-SEM). EDS measurements were performed for elemental composition and mapping of elements using an 80 mm² SDD detector (Oxford Instruments) and AZtecEnergy software from Oxford Instruments. The samples were placed on a carbon conductive tape to conduct the measurements. Transmission electron microscopy (TEM) was performed using an EFTEM Jeol 2200 FS microscope (Jeol, Japan) at an acceleration voltage of 200 keV. Pictures were taken by a SIS MegaView III digital camera (Soft Imaging Systems) and analyzed by AnalySIS v. 2.0 software. Elemental maps were acquired with an SDD detector X-MaxN 80 TS from Oxford Instruments (England). For sample preparation, suspensions were prepared in pure ethanol and drop-cast on a TEM grid (Cu, 200 mesh, Formvar/carbon from TED PELLA, Inc.) and dried overnight at room temperature.

XRD

X-ray powder diffraction data were collected at room temperature on a Bruker D8 Discoverer (Bruker, Germany) powder diffractometer with parafocusing Bragg–Brentano geometry using CuKα radiation (λ = 0.15418 nm, U = 40 kV, I = 40 mA). Data were scanned over the angular range 5–70° (2θ). Data evaluation was performed in the software package EVA.

Raman spectroscopy

InVia Raman microscope (Renishaw, England) in backscattering geometry with a CCD detector was used for Raman spectroscopy. DPSS laser (532 nm, 50 mW) with an applied power of 5 mW and a 50× magnification objective was used for the measurement. Instrument calibration was achieved with a silicon reference, which gives a peak position of 520 cm⁻¹ and a resolution of less than 1 cm⁻¹. The samples were suspended in deionized water (1 mg/ml) and ultrasonicated for 10 min. The suspension was deposited on a small piece of silicon wafer and dried.

Electrochemical measurements for the hydrogen evolution reaction

The electrochemical characterization by means of linear sweep voltammetry (LSV) was performed using an Autolab PGSTAT 204 (Metrohm, Switzerland). A standard three-compartment electrochemical cell was used, equipped with an RDE with a glassy carbon disk (geometric surface area: 0.196 cm²) as a working electrode, a graphite rod as a counter electrode, and Hg/HgSO₄ (0.5 M K₂SO₄) as a reference electrode. HER LSV measurements were performed at room temperature in N₂-saturated aqueous 0.5 M H₂SO₄ solution. LSV plots were corrected for iR drop by applying a 5–10% iR correction to the measured potentials to account for the ohmic losses, as the correction varied depending on the resistance of the samples. For preparing the catalyst ink, catalytic powder (4.0 mg) was dissolved in a mixture (1 mL) of deionized water, isopropanol, and 5% Nafion (v/v/v = 4:1:0.02), followed by sonication for 30 min before use. The working electrode was polished with alumina suspension, washed with deionized water, and finally sonicated in double-distilled water before casting 8.5 μL aliquots of the electrocatalytic ink on the electrode’s surface. Finally, electrochemical impedance spectroscopy (EIS) measurements were acquired from 10⁵ to 10⁻¹ Hz with an AC amplitude of 0.01 V. The EIS measurements were conducted at a potential where significant HER current was recorded, corresponding to −2 mA cm⁻².

Electrochemical energy storage testing

The slurries were composed of 80 wt.% active material (WSe₂, Ti₃C₂Cl₂ MXene, and w-WSe₂/Ti₃C₂Cl₂ hybrid), 10 wt.% polyvinylidene fluoride (PVDF) as the binder, and 10 wt.% carbon black (CB) as the conductive additive. These components were thoroughly dispersed in N-methyl-2-pyrrolidone (NMP), which was used as the solvent. To ensure uniform dispersion, the slurry was stirred overnight at room temperature prior to electrode fabrication. The slurry was cast onto planar copper (Cu) foil (7 μm thickness), which served as the current collector. A doctor blade set at a height of 250 μm was employed to ensure uniform coating of the slurry on the Cu foil. The coated electrodes were dried in a vacuum oven at 100 °C for 12 h to remove residual solvent. The dried electrodes were then cut into circular disks and stored in an argon-filled glovebox to prevent exposure to moisture or oxygen before cell assembly. The electrochemical performance of the prepared anodes was evaluated using a two-electrode CR2032 coin cell configuration with metallic lithium (Li) as the counter and reference electrode. The electrolyte consisted of 1 M LiPF₆ dissolved in a mixture of ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) (1:1:1 by volume), with 1 wt.% vinylene carbonate (VC) added as a stabilizing agent. The cells were assembled in an argon atmosphere, ensuring minimal contamination, and then tested for electrochemical performance using a Neware battery testing system. Galvanostatic charge-discharge cycling was performed within a voltage window of 0.001–3.0 V vs. Li⁺/Li, at an initial current density of 50 mA g⁻¹ to evaluate the specific capacities of the anode materials. The rate capability was assessed by cycling the electrodes under varying current densities of 25, 50, 100, 200, and 400 mA g⁻¹, with each current density being maintained for five consecutive cycles. Cyclic voltammetry (CV) and EIS were employed using an Autolab PGSTAT204 workstation (Eco Chemie, Utrecht, Netherlands) to evaluate the electrochemical performance of WSe₂, Ti₃C₂Cl₂ MXene, and their hybrid in 2032 coin cells. CV tests were performed at a scan rate of 1.0 mV s⁻¹ over a potential range of 0.001–3.0 V vs. Li⁺/Li. EIS measurements were conducted at open circuit voltage (OCV) with an AC perturbation of 10 mV over a frequency range from 100 kHz to 100 mHz.

Electrochemical sensing

Measurements were carried out in a 0.1 M phosphate buffer saline (PBS) at pH 7 under ambient conditions, using a 4-channel potentiostat in a three-electrode electrochemical cell. Glassy carbon (GC) electrode was modified with a 10 μL aliquot of 5 mg ml⁻¹ ethanolic suspension of the WSe₂/Ti₃C₂Cl₂, dried under ambient conditions, and served as the working electrode. Pt foil served as a counter electrode, and Ag/AgCl, 3 M KCl served as a reference electrode. Before every use, the GC electrode was carefully polished with alumina slurry on a polishing pad until a mirror finish was obtained, sonicated in ethanol/water for 7 min, and rinsed thoroughly with distilled water.

CV was measured in a potential range from 0.2 to −0.4 V in the presence of 5 mM H₂O₂ at a scan rate of 25 mV s⁻¹. Amperometry experiments were conducted in stirred (150 rpm) solutions at a polarization potential of −0.3 V, unless stated otherwise.

Discussion

Synthesis of Cl-terminated Ti₃C₂T_x MXene

XRD patterns of the synthesized Ti₃C₂T_x MXene obtained with varying ratios of KCl and CdCl₂ (1:6:2, 1:5:3, 1:3:5, and 1:2:6) are presented in Fig. 1a, with the pristine T₃AlC₂ MAX phase included for comparison. The Ti₃AlC₂ MAX phase exhibits characteristic diffraction peaks at 9.52°, 19.11°, and 38.76° 2θ values, typical of its well-defined layered structure (PDF 04-012-0632).

Fig. 1: Characterization of LAMS-Ti₃C₂Cl₂ MXenes.

a XRD patterns of MXenes synthesized with different ratios of MAX phase: CdCl₂: KCl. b SEM image of Ti₃C₂Cl₂ MXene synthesized with the optimized ratio of 1:3:5, and c corresponding elemental mapping of elements. Scale bars in (c) represent 10 µm.

When different ratios of CdCl₂ and KCl are employed at 700 °C for 24 h, notable changes in the diffraction patterns (Fig. 1a) are observed. For samples prepared with MAX phase: CdCl₂: KCl ratios of 1:6:2, 1:5:3, and 1:3:5, a clear shift of the (002) and (004) diffraction peak positions to lower 2θ values is evident, as indicated by the dotted lines in Fig. 1a, confirming the successful removal of the Al layer and the synthesis of Ti₃C₂T_x MXene. For example, in the MXene synthesized with the ratio 1:3:5, the (002) and (004) diffractions are measured at 7.96 and 15.98°, respectively. The reactions involved in the synthesis are as follows:

$${{\rm{Ti}}}_{3}{\rm{Al}}{{\rm{C}}}_{2}+3{\rm{Cd}}{{\rm{Cl}}}_{2}\mathop{\to }\limits^{{\rm{KCl}},\,700\,^\circ {\rm{C}}}\,{{\rm{Ti}}}_{3}{{\rm{C}}}_{2}+2{\rm{Cd}}+{\rm{Al}}{{\rm{Cl}}}_{3}$$

$${{\rm{Ti}}}_{3}{{\rm{C}}}_{2}+2{\rm{Cd}}{{\rm{Cl}}}_{2}\mathop{\to }\limits^{{\rm{KCl}},\,700\,^\circ {\rm{C}}}\,{{\rm{Ti}}}_{3}{{\rm{C}}}_{2}{{\rm{Cl}}}_{2}+2{\rm{Cd}}$$

Here, KCl acts as a molten co-solvent, providing stability and homogeneity to facilitate the reaction. After the reaction, residual cadmium metal and other reaction residuals are dissolved in concentrated HCl, and the Ti₃C₂Cl₂ MXene is obtained as a powder. For more details on the synthesis, please see the Experimental section.

These results confirm that the ratios 1:6:2, 1:5:3, and 1:3:5 are favorable for synthesizing Cl-terminated Ti₃C₂T_x MXene. Among these, the ratio of 1:3:5 is particularly noteworthy, as it achieves successful MXene synthesis while significantly reducing the amount of toxic CdCl₂ used in the etching process. Notably, at least five parts of KCl are required for effective etching, highlighting the potential for optimizing the CdCl₂: KCl ratio to achieve safer and more environmentally friendly protocols using the LAMS method without compromising the structural integrity of the MXene. In contrast, the sample synthesized with a 1:2:6 ratio shows no synthesis of MXene, as its XRD pattern retains the characteristic peaks of the T₃AlC₂ MAX phase at 9.49° and 19.08°, indicating incomplete conversion and the presence of other mixed phases.

SEM-EDS characterization was performed for the MXene synthesized with a 1:3:5 ratio to further validate the effectiveness of the optimized ratio. As observed in Fig. 1b, the SEM image reveals a typical accordion-like morphology, characteristic of multilayered Ti₃C₂T_x MXenes, confirming the successful etching of the corresponding MAX phase. The image demonstrates the well-preserved layered structure of the MXene synthesized with the optimized Ti₃AlC₂:CdCl₂:KCl ratio. Additionally, this method enables the synthesis of MXene with Cl terminations, as observed in the EDS elemental mapping in Fig. 1c. A uniform distribution of titanium (Ti) and chlorine (Cl) is evident throughout the layered structure, with only minor traces of aluminum (Al) particles present. The uniform distribution of Cl as a surface termination highlights the effectiveness of the 1:3:5 ratio in synthesizing Cl-terminated MXenes. This MXene, synthesized with the 1:3:5 ratio, will be used for the next steps of the study and designated as Ti₃C₂Cl₂.

Synthesis of WSe₂/Ti₃C₂T_x MXene hybrids

After the successful synthesis of the Ti₃C₂Cl₂ MXene, this study proceeded to the synthesis of the hybrid materials of WSe₂/Ti₃C₂Cl₂ MXene with varying compositions: one with a higher ratio of WSe₂ (designated as w-WSe₂/Ti₃C₂Cl₂) and the other with a higher ratio of MXene (designated as m-WSe₂/Ti₃C₂Cl₂). The hybrid materials were prepeared by employing a straightforward solvothermal reaction, in which WSe₂ was deposited onto MXene through the condensation of tungsten hexacarbonyl and selenium. The morphologies of these hybrids are clearly illustrated in the scanning electron microscopy (SEM) images shown in Fig. 2. In the sample m-WSe₂/Ti₃C₂Cl₂ (Fig. 2a), the SEM image reveals that the MXene serves as a prominent scaffold, providing a layered structure for the in situ growth of WSe₂ nanoflowers on its surface. The yellow square in Fig. 2a highlights the WSe₂ nanostructures on the Ti₃C₂Cl₂ MXene, confirming the formation of the hybrid material. Conversely, the sample w-WSe₂/Ti₃C₂Cl₂ (Fig. 2b), exhibits a morphology dominated by WSe₂, with the MXene layers embedded within the WSe₂ matrix. The yellow square in Fig. 2b marks the presence of the Ti₃C₂Cl₂ MXene layers embedded by WSe₂.

Fig. 2: Morphology of WSe₂ and hybrid materials.

SEM images of (a) m-WSe₂/Ti₃C₂Cl₂, with the yellow square highlighting WSe₂ onto the Ti₃C₂Cl₂ surface. b w-WSe₂/Ti₃C₂Cl₂, with the yellow square indicating Ti₃C₂Cl₂ embedded within the WSe₂. c pristine WSe₂.

Additionally, the SEM image of pristine WSe₂ (Fig. 2c) shows a characteristic flower-like morphology, providing an apparent reference for the WSe₂ structure in the hybrids. Figures S1 and S2 provide further EDS analysis of individual components, confirming the uniform distribution of elements in the hybrids. Table S1 summarizes the quantification of elements (atomic%) determined by SEM/EDS analysis for all the synthesized materials.

XRD and Raman spectroscopy were employed to characterize the hybrid material. The XRD patterns of w-WSe₂/Ti₃C₂Cl₂ MXene further indicate the successful preparation of the hybrid. Figure 3a displays the reflection signals for the plane reflections corresponding to the hexagonal WSe₂ with a P63/mmc space group (reference JCPDF no. 38-1388)³⁶. WSe₂ shows (002), (100), (103), (105), and (110) peaks. In the hybrid material (002) and (103) peaks are present while (100) and (110) follow a downward shift of 3.2° and 2.7°, respectively, signifying increased interlayer distance following hybridization²¹. Additionally, peaks at 8.15, 16.16°, 24.34°, 40.89°, 49.02°, and 58.06° originating from the MXene are evident in the hybrid material. All the above confirm the hybrid’s successful formation and the interactions between its constituent components. A similar shift is evident in the Raman spectroscopy results. Intact WSe₂ shows bands at 128, 202, and 236 cm⁻¹, corresponding to J₁, J₂, and J₃, which are characteristic of the metallic 1T octahedral phase of WSe₂ (Fig. 3b)³⁷. Additionally, the band at 245 cm⁻¹ for WSe₂ results from the overlapping E₂^g and A₁^g modes, typical of the 2H phase³⁷. Furthermore, Ti₃C₂Cl₂ exhibits characteristic vibrations, including the A_1g (Ti, C, O) mode at 206.5 cm⁻¹ and broad bands within the 260 and 405 cm⁻¹, attributed to the in-plane (E_g) modes of surface groups attached to Ti atoms^38,39. In the 580–730 cm⁻¹ range, known as the carbon region, a band at 606 cm⁻¹ and a shoulder-like band at 704 cm⁻¹ correspond to Ti (E_g) and C (A_1g) vibrations, respectively^38,39. In the hybrid material, bands deriving from both individual components are observed: J₁–J₂ bands are seen deriving from WSe₂ are obvious along with the band at 245 cm⁻¹.WSe₂’s 256 cm⁻¹ band appears downshifted to 253 cm⁻¹ in the hybrid. This region also overlaps with the Eg mode associated with Ti atoms in the MXene, indicating strong interfacial coupling between WSe₂ and MXene layers upon hybridization. Also, small bands at 405–606 cm⁻¹ are evident³¹.

Fig. 3: Structural and vibrational analysis of pristine and hybrid WSe₂-based materials.

a XRD patterns and (b) Raman spectra for w-WSe₂/Ti₃C₂T₂ MXene (red), WSe₂ (black), and Ti₃C₂T₂ MXene (blue).

The analysis of the hybrid w-WSe₂/Ti₃C₂Cl₂ was further complemented by TEM analysis. Figures 4a and S3 display TEM images of the hybrid, confirming the presence of WSe₂ nanosheets consistent with SEM observations (Fig. 2b). The TEM imaging highlights the flower-like morphology of the WSe₂ nanostructures, formed by interconnected crystalline nanosheets. Furthermore, high-resolution TEM (HRTEM) imaging of the hybrid (Fig. S3) shows well-defined lattice fringes, indicative of its crystalline structure. The corresponding fast Fourier Transform (FFT) patterns of selected areas (insets of Fig. S3) confirm the structural order of the w-WSe₂/Ti₃C₂Cl₂. The spatial distribution of elements within the hybrid is shown through STEM-EDS mapping, revealing the integration of Ti₃C₂Cl₂ MXene within the WSe₂ nanosheets. In line with the SEM image of the w-WSe₂/Ti₃C₂Cl₂ (Fig. 2b), WSe₂ dominates the structure in the hybrid, consistent with its higher ratio in the composition. The EDS mapping (Fig. 4a) confirms the presence and distribution of Ti and Cl elements from the MXene, further supporting the synthesis of the hybrid.

Fig. 4: TEM characterization of w-WSe₂/Ti₃C₂Cl₂ hybrid and starting materials.

a TEM image of the w-WSe₂/Ti₃C₂Cl₂ hybrid with corresponding EDS elemental maps showing the distribution of W, Se, Ti, and Cl elements; b TEM image of WSe₂, with corresponding EDS elemental maps showing the uniform distribution of W and Se; c TEM image of Ti₃C₂Cl₂ MXene, with corresponding EDS elemental maps showing the uniform distribution of Ti and Cl. Scale bars for mapping in (a) represent 500 nm. Scale bars for elemental mapping in (b) and (c) represent 250 nm.

Additionally, the TEM image of pristine WSe₂ (Fig. 4b) highlights its characteristic morphology, and the elemental mapping confirms the uniform distribution of W and Se in the nanosheets. The structural and compositional features of Ti₃C₂Cl₂ MXene are presented in Fig. 4c, which illustrates its characteristic layered morphology consistent with the SEM (Fig. 1b). The elemental mapping (Fig. 4f) shows a uniform distribution of Ti and Cl elements, another evidence of the Cl-terminated MXene. TEM analysis of both the hybrid and starting materials (WSe₂ and Ti₃C₂Cl₂) aligns well with the SEM-EDS results, providing further evidence of the synthesis of the w-WSe₂/Ti₃C₂Cl₂ hybrid by the proposed solvothermal method.

WSe₂/Ti₃C₂Cl₂ hybrids as electrocatalysts for HER

Next, the efficacy of both WSe₂/Ti₃C₂Cl₂ electrocatalysts and reference materials WSe₂, Ti₃C₂Cl₂ MXene, and Pt/C (20 wt.%) for HER was assessed through LSV in an aqueous 0.5 M H₂SO₄ electrolyte (Fig. 5). The hybrid with the higher amount of WSe₂ exhibits excellent electrocatalytic activity, indeed much higher compared to that with the lower amount of WSe₂ (Fig. 5a). w-WSe₂/Ti₃C₂Cl₂ starts the production of hydrogen bubbles at −0.14 V vs RHE, 70 and 110 mV lower compared to pristine Ti₃C₂Cl₂ MXene and WSe₂, respectively. At the benchmark potential of −10 mA cm⁻², the w-WSe₂/Ti₃C₂Cl₂ hybrid presents an overpotential of just 190 mV, i.e., at −0.19 V vs RHE, 160 mV lower than the m-WSe₂/Ti₃C₂Cl₂ and only 159 mV higher than Pt/C. On the contrary, bare Ti₃C₂Cl₂ and WSe₂ show much higher overpotentials of 400 and 446 mV, respectively.

Fig. 5: Electrochemical evaluation of HER activity and stability in aqueous 0.5 M H₂SO₄.

a iR- corrected LSVs for HER obtained at 1600 rpm rotation speed and 5 mV s⁻¹ scan rate before (solid lines) and after 10,000 cycles (dashed lines), in aqueous (b) Tafel slopes, and (c) Nyquist plots for w-WSe₂/Ti₃C₂Cl₂ (red), m-WSe₂/Ti₃C₂Cl₂ (pink), Ti₃C₂Cl₂ MXene (blue), WSe₂ (black) and Pt/C (20 wt.%) (gray).

The reaction mechanism was analyzed by the extracted Tafel slopes from the LSV curves and by performing Electrochemical impedance spectroscopy (EIS) as seen in Fig. 5b, c, respectively. Consistent with the LSV results, w-WSe₂/Ti₃C₂Cl₂ exhibited the lowest Tafel slope value of 50 mV/dec, suggesting that the rate-determining step is the Heyrovsky step. Here, protons undergo initial adsorption onto the electrode surface through a reduction process (Volmer step), followed by molecular H₂ generation, where hydrogen atoms desorb from the electrode (Heyrovsky step). Conversely, m-WSe₂/Ti₃C₂Cl₂, along with pristine WSe₂ and Ti₃C₂Cl₂, displayed higher Tafel slopes of 144, 186, and 112 mV/dec, respectively, indicating slower reaction kinetics due to proton adsorption. EIS results further support the above findings. Conducted at a potential corresponding to −2 mA cm⁻² and fitted to a Randles circuit, Nyquist plots showed that w-WSe₂/Ti₃C₂Cl₂ had the lowest charge transfer resistance (R_ct) at 18.6 Ω, significantly lower than the R_ct m-WSe₂/Ti₃C₂Cl₂ (141.1 Ω), underscoring the former’s superior conductivity. Pristine WSe₂ and Ti₃C₂Cl₂ MXene showed higher R_ct values of 74.6 and 177.5 Ω, respectively, indicating slower kinetics. The enhanced reaction kinetics of w-WSe₂/Ti₃C₂Cl₂, corroborated by Tafel and EIS data, can be attributed to the direct contact enabled by the robust deposition of WSe₂ onto Ti₃C₂Cl₂ MXene, facilitating efficient electron transfer within the hybrid structure. Additionally, the abundant flower-like WSe₂ in the hybrid provides a high surface area with more exposed active edge sites for enhanced HER performance. Despite pristine Ti₃C₂Cl₂ MXene having higher HER electrocatalytic activity than pristine WSe₂, its lower intrinsic conductivity limits its efficiency. In the w-WSe₂/Ti₃C₂Cl₂, WSe₂’s superior conductivity and abundant active sites contribute to a more effective HER performance than a Ti₃C₂Cl₂ MXene-rich composition.

The electrochemically active surface area (ECSA) is a crucial parameter for understanding charge transport behavior in hybrid materials. ECSA was determined using the equation: ECSA = C_dl/C_s, where C_dl is the electrochemical double-layer capacitance, and C_s represents the specific capacitance for a flat surface of 1 cm², assumed to be 40 µF cm⁻² for the electrode¹³. To calculate ECSA, cyclic voltammograms of the hybrids, along with WSe₂ and Ti₃C₂Cl₂ MXene, were recorded in a non-Faradaic region at scan rates from 50 to 500 mV s⁻¹ (Fig. S4). The w-WSe₂/Ti₃C₂Cl₂ hybrid achieved the highest ECSA value of around 21.7 cm², followed by the m-WSe₂/Ti₃C₂Cl₂ hybrid with 9.0 cm². In comparison, WSe₂ and Ti₃C₂Cl₂ MXene showed lower values of approximately 3.6 and 3.1 cm², respectively. These findings align with overall electrocatalytic observations, as w-WSe₂/Ti₃C₂Cl₂ exhibits abundant active sites and a larger surface area due to the higher presence of WSe₂. Higher ECSA values reflect a greater active surface area of catalytic sites, which is directly linked to improved electrocatalytic performance.

Finally, the stability of both hybrids and the pristine materials was examined by successive scanning of 10,000 electrocatalytic cycles, as presented in Fig. 5a. Notably, both hybrids exhibited a minimal potential loss of only 20 mV, while WSe₂ and Ti₃C₂Cl₂ showed a larger overpotential of 40–50 mV. Furthermore, chronoamperometric analysis was conducted at a constant applied potential of −0.16 V vs. RHE for 10,000 with a rotation speed of 1600 rpm (Fig. S5), to further evaluate the durability of w-WSe₂/Ti₃C₂Cl₂. w-WSe₂/Ti₃C₂Cl₂ exhibited excellent stability with a negligible current density loss of about 11.5%.

These results consequently point out the stability of WSe₂/Ti₃C₂Cl₂ hybrids and, in this regard, their potential for long-time applications in demanding electrochemical processes where stability is an important issue for practical use. All tested parameters for HER are summarized in Table S2.

After evaluating the HER performance of all hybrid compositions in a N₂-saturated aqueous 0.5 M H₂SO₄ electrolyte, the hybrid with the optimal WSe₂/Ti₃C₂Cl₂ MXene ratio, i.e., with higher WSe₂ content, was identified as the best-performing material due to its high electrocatalytic activity.

Having identified the optimized hybrid, we proceeded to evaluate its potential for additional energy-related and electrochemical applications. Applications like HER, LIBs, and electrochemical sensing rely on efficient electron transfer, high catalytic activity, and structural stability, all of which are intrinsic to the hybrid’s design. Specifically, the strong electrocatalytic activity and enhanced electron transfer properties of the optimized hybrid made it a promising candidate for both energy storage as an anode material in LIBs and electrochemical sensing for the amperometric determination of H₂O₂.

w-WSe₂/Ti₃C₂Cl₂ MXene hybrid as an anode for LIBs

The electrochemical performance of the w-WSe₂/Ti₃C₂Cl₂ hybrid and bare WSe₂ was evaluated. The lithiation of TMDs, such as WS₂, MoS₂, and WSe₂, typically involves a two-step intercalation-conversion mechanism⁴⁰. During lithiation, Li⁺ ions intercalate into WSe₂ to form an intermediate Li_xWSe₂ phase, which undergoes a conversion reaction to yield lithium selenide (Li₂Se) and elemental tungsten (W) embedded in the matrix⁴¹. Conversely, during delithiation, Li₂Se and W recombine to regenerate the Li_xWSe₂ structure, from which Li⁺ ions are deintercalated⁴². Galvanostatic charge/discharge tests revealed significant differences in the electrochemical behaviors of the w-WSe₂/Ti₃C₂Cl₂ hybrid and bare WSe₂. Voltage profiles recorded at 50 mA g⁻¹ within a voltage range of 0.001–3.0 V vs. Li⁺/Li showed that bare WSe₂ (Fig. 6b) exhibited no discernible plateaus or characteristic features, reflecting sluggish lithiation/delithiation kinetics. Likewise, no prominent lithiation/delithiation peaks were observed for the w-WSe₂/Ti₃C₂Cl₂ hybrid (Fig. 6c). While bare WSe₂ exhibited an initial discharge capacity of 661 mAh g⁻¹, declining to 240 mAh g⁻¹ after 20 cycles, the w-WSe₂/Ti₃C₂Cl₂ hybrid demonstrated a much higher initial discharge capacity of 1255 mAh g⁻¹. It also retained a similar discharge capacity to WSe₂ of 244 mAh g⁻¹ after 20 cycles (Fig. 6d). Additionally, intact Ti₃T₂Cl₂ MXene shows an initial discharge capacity of 393 mAh g⁻¹, which decreased to 116 mAh g⁻¹ after 20 cycles (Fig. 6a). These results highlight the synergistic effect between WSe₂ and Ti₃C₂Cl₂ within the hybrid structure, which enhances initial capacity while maintaining stability over cycling.

Fig. 6: Electrochemical evaluation of w-WSe₂/Ti₃C₂Cl₂ hybrid, WSe₂, and Ti₃C₂Cl₂ MXene in the lithium coin cells.

(a) Charge/discharge curves of Ti₃C₂Cl₂ MXene at 50 mA g⁻¹. (b) Charge/discharge curves of WSe₂ at 50 mA g⁻¹. (c) Charge/discharge curves of w-WSe₂/Ti₃C₂Cl₂ hybrid at 50 mA g⁻¹. (d) Cycling performance comparison of Ti₃C₂Cl₂ MXene, WSe₂, and w-WSe₂/Ti₃C₂Cl₂ at 50 mA g⁻¹. (e) Rate performance comparison of WSe₂ and the w-WSe₂/Ti₃T₂Cl₂ under various current densities.

The rate capability of the hybrid, evaluated under current densities ranging from 25 to 400 mA g⁻¹ (Fig. 6e),demonstrated superior performance achieving specific capacities of 903, 839, 340, 123, and 50 mAh g⁻¹ at 25, 50, 100, 200, and 400 mA g⁻¹, respectively, in contrast to the significantly lower performance of bare WSe₂. The significant enhancement in rate and cycling performance can be attributed to two primary factors: (1) the immediate contact between WSe₂ grown onto the Ti₃T₂Cl₂ MXene matrix, enables charge transfer and increases conductivity within the w-WSe₂/Ti₃C₂Cl₂, and (2) the unique flower-like morphology of WSe₂ nanostructures, formed by interconnected crystal nanosheets providing better mechanical stability. This architecture ensures the uniform growth of few-layered WSe₂ nanoflowers on Ti₃C₂Cl₂ MXene, effectively accommodating volume changes during lithiation/delithiation and preventing mechanical degradation^43,44. The integration of WSe₂ onto w-Ti₃C₂Cl₂ MXene improves electrical conductivity and structural stability, resulting in a commendable electrochemical performance. These findings underscore the w-WSe₂/Ti₃C₂Cl₂ hybrid’s potential as a promising anode material for advanced lithium-ion batteries.

The Nyquist plots in Fig. S6a were obtained from fresh cells. Among the three samples, the w-WSe₂/Ti₃C₂Cl₂ hybrid shows the smallest semicircle, indicating the lowest interfacial resistance and most efficient charge transfer. In contrast, pristine WSe₂ shows a moderate semicircle, while Ti₃C₂Cl₂ MXene alone exhibits the largest one, likely due to poor electrolyte compatibility as a standalone electrode material. While Ti₃C₂Cl₂ MXene itself has relatively low conductivity, its integration with WSe₂ in the hybrid structure significantly enhances overall conductivity. These results demonstrate that the hybrid structure exploits the complementary roles of both components. Ti₃C₂Cl₂ MXene serves as a structural scaffold that promotes immediate contact and efficient charge transfer, while WSe₂ contributes high Li-ion storage activity,together resulting in enhanced electrochemical performance. The CV peaks of the hybrid electrode show a noticeably higher current response than those of pristine WSe₂, indicating enhanced redox kinetics and faster Li⁺ intercalation/deintercalation dynamics enabled by the conductive Ti₃C₂Cl₂ MXene framework (Fig. S6b). The Ti₃C₂Cl₂ MXene plays a crucial role in enhancing the electrochemical performance by providing a conductive, hydrophilic scaffold that facilitates electrolyte penetration. The direct contact between the MXene scaffold and WSe₂ facilitates more efficient Li⁺ transport, improving the interfacial charge transfer and lithium intercalation/deintercalation kinetics. In addition, the w-WSe₂/Ti₃C₂Cl₂ hybrid electrode exhibits a significantly reduced peak voltage separation (ΔV≈720 mV) compared to pristine WSe₂ (ΔV≈1350 mV), indicating lower polarization and improved redox reversibility. Although the ΔV values remain relatively high, which may be attributed to the intrinsic kinetics of layered WSe₂ and interfacial effects, the hybrid structure clearly improves the charge transfer and Li⁺ diffusion behavior. This is further corroborated by the increased redox peak currents and closed CV profiles.

w-WSe₂/Ti₃C₂Cl₂ hybrid as a sensor for H₂O₂

The sensing features of w-WSe₂/Ti₃C₂Cl₂ were investigated and compared with the pristine materials by assessing their electrocatalytic activity towards the reduction of H₂O₂ through CV in the presence of 5 mM in 0.1 M PBS (pH 7) over the potential range from 0.2 to −0.4 V at a scan rate of 25 mV s⁻¹. Results presented in Fig. 7a–d reveal that plain GC shows no response upon the addition of H₂O₂, while the Ti₃C₂Cl₂ MXene demonstrates only a negligible current response. On the other hand, both WSe₂ and w-WSe₂/Ti₃C₂Cl₂ exhibit a significant increase in cathodic current upon the addition of H₂O₂, with the w-WSe₂/Ti₃C₂Cl₂ hybrid displaying nearly double the performance of WSe₂ alone. This is clear evidence that the immediate contact between WSe₂ and Ti₃C₂Cl₂ MXene within the hybrid material imparts superior electrocatalytic activity for H₂O₂ reduction, highlighting its capability for enhanced sensing features of this hybrid material.

Fig. 7: Electrochemical sensing of H₂O₂ in 0.1 M PBS (pH 7).

a–d CVs of plain GC, Ti₃C₂Cl₂ MXene/GC, WSe₂/GC, and w-WSe₂/Ti₃C₂Cl₂/GC in the absence and in the presence of 5 mM H₂O₂ at a scan rate of 25 mV s⁻¹. Amperometric curves of w-WSe₂/Ti₃C₂Cl₂/GC: e at different polarization potentials for H₂O₂ concentration ranging from 10 to 100 μM, along with the respective calibration plots, f at −0.3 V for H₂O₂ concentration ranging from 1 to 88 μM along with the corresponding calibration plot, g at −0.3 V with similarly prepared sensors over three consecutive additions of 5 μM H₂O₂ along with current response shown for each addition.

To this end, the sensing capabilities of w-WSe₂/Ti₃C₂Cl₂ were explored using the chronoamperometric technique, correlating the observed catalytic currents with the added concentration of H₂O₂. Aiming to optimize the sensor’s experimental conditions, we investigated its behavior at different values of polarization potentials from −0.2 to −0.4 V over a concentration range of 10–100 μM. The amperometric curves in Fig. 7e show that higher potential values increase the current response, while it can affect the stability of the signal. Even though −0.4 V offers higher current responses upon the addition of H₂O₂, it lacks stability and linearity over the selected concentration range. Balancing the need for the highest possible analyte signal with the lowest potential value, and given the comparable performance of the sensor at −0.35 V and −0.30 V, the latter was chosen as the optimal polarization potential.

Later on, the calibration features of the w-WSe₂/Ti₃C₂Cl₂ modified GC were assessed through chronoamperometry at an applied potential of −0.3 V. Figure 7f demonstrates the amperometric curve occurred in the presence of H₂O₂ over the concentration range of 1–88 μΜ. The cathodic current attributed to H₂O₂ addition is linearly correlated with the tested concentration range of H₂O₂ (Fig. 7f inset), with the data fitting the equation ip (μA) = −0.0213[H₂O₂] (μM) − 0.0049 (R² = 0.9957). The limit of detection (LOD), calculated as 3σ/slope, was found to be 0.6 μM.

The w-WSe₂/Ti₃C₂Cl₂/GC analytical figures-of-merit compare favorably with most of the reported electrochemical sensors for H₂O₂ based on 2D structured materials (Table S3) in terms of LOD and limit of quantification (LOQ). These features, in combination with the relatively low polarization potential along with the absence of the need for any deaeration steps in the working solution, render w-WSe₂/Ti₃C₂Cl₂ a highly performing sensing electrocatalyst for H₂O₂.

The reproducibility of the developed sensor was evaluated over five similarly prepared electrodes by addressing the catalytic current stemming from three consecutive additions of 5 μM H₂O₂. Figure 7g illustrates the amperometric curves of the five sensors along with the current response for each of the H₂O₂ additions (Fig. 7g inset). Each one of the three additions in the same sensor causes a -small but dissimilar- dilution to the working solution, resulting in a slightly different concentration of H₂O₂. Considering that, the interelectrode relative standard deviation (RSD) was calculated for the three H₂O₂ additions separately, and found to be 7.74%, 8.49%, and 7.87% for the first, second, and third addition, respectively. These values are deemed more than satisfactory and highlight that applying w-WSe₂/Ti₃C₂Cl₂ on a GC leads to sensors with fairly good reproducibility over consecutive measurements.

Developing efficient multifunctional materials is essential for tackling energy challenges, environmental safety, and public health concerns. Beyond good performance, a facile fabrication approach is highly desirable. In this context, we developed a hybrid material comprising WSe₂ and Ti₃C₂Cl₂ MXene. First, Ti₃C₂Cl₂ MXene was synthesized using the LAMS approach, which combined KCl and CdCl₂ to achieve Cl-terminated surfaces. This approach not only ensures Cl-terminated MXene surfaces but also minimizes the use of CdCl₂, contributing to reduced toxicity. This was followed by a simple solvothermal process, enabling the in situ growth of WSe₂ nanoflowers onto Ti₃C₂Cl₂ MXene, forming a well-integrated hybrid material. The hybrid with a higher WSe₂ content exhibited outstanding HER electrocatalytic performance, achieving a low overpotential of just 190 mV at −10 mA cm⁻². The strong electronic interaction between WSe₂ and Ti₃C₂T₂, facilitated by in situ growth, significantly enhances charge transfer and accelerates reaction kinetics, leading to high HER electrocatalytic activity. Additionally, w-WSe₂/Ti₃C₂T₂ demonstrated excellent stability, with only a slight increase in overpotential after 10,000 cycles. After optimizing the WSe₂-to-MXene ratio for HER performance in acidic conditions, we explored its potential in other applications. As an anode material for lithium-ion batteries, w-WSe₂/Ti₃C₂Cl₂ exhibited a significantly higher initial discharge capacity of 1255 mAh g⁻¹, nearly twice that of WSe₂ (661 mAh g⁻¹) and more than three times that of Ti₃C₂T₂ (394 mAh g⁻¹). It also demonstrated enhanced rate capability and cycling stability. This improvement is attributed to the hybrid’s efficient architecture, which promotes charge transfer and conductivity, while the flower-like morphology of WSe₂ accommodates volume changes during lithiation/delithiation and prevents mechanical degradation. Furthermore, the hybrid’s architecture,through the direct contact between its components, offers enhanced sensing capabilities. The w-WSe₂/Ti₃C₂Cl₂ hybrid demonstrated superior electrocatalytic activity for H₂O₂ reduction compared to WSe₂ alone. The optimized w-WSe₂/Ti₃C₂Cl₂/GC sensor achieved a remarkable sensitivity, with a LOD of 0.6 μM, along with excellent reproducibility, positioning it as a promising electrocatalyst for H₂O₂ sensing. Overall, the development of easily fabricated but highly effective nanomaterials is vital for electrochemical applications, where properties like conductivity, stability, and catalytic activity are essential for promoting electron transfer, electrocatalytic reactions, and energy storage. These insights highlight the promise of the WSe₂/Ti₃C₂Cl₂ hybrid as an excellent option for energy-related and sensing applications.