Functionalization Techniques for Two-Dimensional Transition Metal Dichalcogenides

Two-dimensional transition metal dichalcogenides (TMDs) have emerged as versatile materials for electronics, optoelectronics, sensing and catalysis owing to their atomically thin architectures, tunable band gaps and extensive surface areas. Functionalization techniques enable the precise tailoring of these intrinsic properties by introducing chemical groups, heterostructures or defects in a controlled fashion. Broadly, strategies encompass covalent methods—where robust chemical bonds are formed between molecular entities and the TMD lattice—and non-covalent or supramolecular approaches that exploit π–π stacking, hydrogen bonding or coordination chemistry. Defect engineering utilises intrinsic or intentionally generated vacancies, dopants or phase transformations to create reactive sites for subsequent modification. Surface functionalisation may involve organic linkers, metal nanoparticles, polymers or molecular receptors, leading to enhanced photoluminescence, charge transport, catalytic activity and environmental stability. The construction of van der Waals and covalently cross-linked heterostructures further extends the functional palette by combining distinct 2D layers. Electrochemical techniques permit in situ derivatisation of basal planes and edges, while microfluidic and fluid-phase assemblies offer scalable routes to continuous films. Collectively, these advances underpin high-performance sensors, energy conversion devices, self-healing composites and quantum architectures, with ongoing efforts directed at achieving reproducibility, selectivity and industrial scalability.

Research from Nature Portfolio

Recent work has established a low-cost route to covalently bonded MoS2–graphene heterostructures using bifunctional organic linkers equipped with dual anchoring sites. This approach produces uniformly alternating layers with tunable interlayer distances, as confirmed by surface-enhanced Raman spectroscopy, and yields significant modulation of optical absorption, photoluminescence and electrochemical behaviour. By adjusting linker length and chemistry, the interlayer coupling and electronic interactions can be finely controlled, opening pathways to customised optoelectronic platforms and next-generation energy storage systems.

Research from all publishers

In solution-phase studies, defect-rich MoS2 flakes have been covalently grafted with terpyridine-thiol receptors to create ultrasensitive and highly selective chemiresistive sensors for cobalt(II) ions. A microfluidic healing process of sulphur vacancies yields large, continuous hybrid films that detect Co2+ at picomolar concentrations, illustrating the power of vacancy-mediated covalent functionalization.

A comprehensive review of atomic and structural modifications presents an integrated overview of post-treatment strategies for 2D TMDs and their heterostructures. It details vacancy generation, substitutional doping, covalent and non-covalent functionalization, and phase transitions, linking these atomic-scale modifications to enhanced performance in electronics, sensing, catalysis and neuromorphic devices, and emphasising the interplay between defect sites and macroscopic functionality.

An electrolytic functionalization protocol for thermodynamically stable 2H-phase MoS2 employs cathodic potentials in the presence of organoiodides to bind acetic acid or aniline moieties to surface sulphur atoms. The resulting water-dispersible nanosheets demonstrate markedly improved catalytic activity for nitroarene and dye reduction, as the bound functional groups enhance reactant adsorption and facilitate charge transfer, offering a versatile platform for environmental remediation.

Functionalization Techniques for Two-Dimensional Transition Metal Dichalcogenides publication trend

The graph below shows the total number of articles in functionalization techniques for two-dimensional transition metal dichalcogenides across all publications each year (not limited to Nature Index journals).

Technical terms

2D transition metal dichalcogenides (TMDs): Layered materials comprising a transition metal atom sandwiched between two chalcogen atoms, forming atomically thin sheets.

Exfoliation: Separation of bulk layered crystals into individual two-dimensional nanosheets.

Defect engineering: Controlled introduction or repair of atomic-scale imperfections such as vacancies or dopant atoms to create reactive sites or tune properties.

Covalent functionalization: Formation of strong chemical bonds between functional molecules and lattice atoms of a TMD.

Non-covalent functionalization: Attachment of molecules via weaker interactions, including π–π stacking, hydrogen bonding or electrostatic forces.

van der Waals heterostructure: Layered assemblies of different two-dimensional materials held together by weak intermolecular forces.

Photoluminescence (PL): Emission of light from a material following electronic excitation by photons.

Chemiresistive sensor: A device that detects chemical species through changes in electrical resistance upon analyte binding.

References

1. High Selectivity and Sensitivity in Chemiresistive Sensing of Co(II) Ions with Liquid‐Phase Exfoliated Functionalized MoS2: A Supramolecular Approach. Small (2023).
2. Fabrication of covalently bonded MoS2–graphene heterostructures with different organic linkers. Communications Materials (2024).
3. Atomic and structural modifications of two-dimensional transition metal dichalcogenides for various advanced applications. Chemical Science (2022).
4. Molecular Functionalization of 2H-Phase MoS2 Nanosheets via an Electrolytic Route for Enhanced Catalytic Performance. ACS Applied Materials & Interfaces (2021).