Photoelectrochemical Applications of Transition Metal Dichalcogenides

Transition metal dichalcogenides (TMDs) encompass a class of layered semiconductors with the general formula MX₂ (M = transition metal, X = chalcogen). Their atomically thin morphology, tunable band gaps and abundant edge sites render them attractive for photoelectrochemical (PEC) processes. In PEC water splitting, TMDs serve as photocathodes or photoanodes, driving hydrogen evolution and oxygen generation under illumination. Key metrics include photocurrent density, incident photon-to-current efficiency and half-cell solar-to-hydrogen conversion efficiency. Strategies to enhance performance focus on controlled synthesis of large-area films, texture engineering, heterojunction formation, defect passivation and co-catalyst decoration. Advances in interfacial charge separation, band alignment and scalable fabrication promise to accelerate the deployment of TMD-based devices for sustainable hydrogen production, solar fuel generation and environmental remediation.

Research from Nature Portfolio

Recent studies have reported scalable fabrication and performance optimisation of WSe₂ films for PEC hydrogen production. One approach employs self-assembly of few-layer WSe₂ flakes at liquid/liquid interfaces to yield large-area, highly aligned thin films. These electrodes exhibit sustained p-type photocurrents around 1 mA cm⁻² under simulated solar irradiation and achieve solar-to-hydrogen conversion when coupled with a platinum catalyst. Another strategy uses an amorphous solid-liquid-crystalline solid transformation with palladium promoters to produce highly (001)-textured p-type WSe₂ thin films. In situ photochemical deposition of Pt at edge sites facilitates efficient electron transfer, yielding photocurrent densities up to 2.5 mA cm⁻² in acidic electrolyte under AM 1.5 illumination.

Photoelectrochemical Applications of Transition Metal Dichalcogenides publication trend

The graph below shows the total number of articles in photoelectrochemical applications of transition metal dichalcogenides across all publications each year (not limited to Nature Index journals).

Technical terms

Transition metal dichalcogenide (TMD): Layered semiconductors of the form MX₂ with tunable electronic properties.

Photoelectrochemical (PEC) water splitting: Light-driven electrochemical process converting water into hydrogen and oxygen at semiconductor electrodes.

Incident photon-to-current efficiency (IPCE): Ratio of electrons generated to incident photons at a given wavelength.

Type II heterojunction: Semiconductor interface with staggered band edges that promotes spatial separation of electrons and holes.

Photocurrent density: Current per unit electrode area generated under illumination (mA cm⁻²).

Basal plane and edge sites: Flat faces and peripheral regions of layered crystals, differing in catalytic and recombination behaviour.

Co-catalyst decoration: Deposition of catalytic nanoparticles on a semiconductor surface to enhance reaction kinetics.

References

1. Self-assembled 2D WSe2 thin films for photoelectrochemical hydrogen production. Nature Communications (2015).
2. Highly (001)-textured p-type WSe2 Thin Films as Efficient Large-Area Photocathodes for Solar Hydrogen Evolution. Scientific Reports (2017).
3. Structural Features Dictate the Photoelectrochemical Activities of Two-Dimensional MoSe2 and WSe2 Nanostructures. The Journal of Physical Chemistry C (2021).
4. One-Pot Synthesis of Chlorophyll-Assisted Exfoliated MoS2/WS2 Heterostructures via Liquid-Phase Exfoliation Method for Photocatalytic Hydrogen Production. Nanomaterials (2021).
5. Peeling off the surface: Pt‐decoration of WSe2 nanoflakes results in exceptional photoelectrochemical HER activity. SusMat (2022).