NiSe₂ Cocatalyst-Modified WO₃ for Efficient Photoelectrochemical Water Splitting

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Efficient solar water splitting requires photoanodes with optimal light absorption, charge separation, and transport.
• Existing photoanodes face challenges in achieving high performance for water splitting.

Purpose of the Study:

• To develop a highly efficient photoanode for photoelectrochemical (PEC) water splitting.
• To investigate the synergistic effects of WO3 and NiSe2 nanoparticles in a heterojunction structure.

Main Methods:

• Fabrication of WO3/NiSe2 heterostructure photoanodes.
• Photoelectrochemical measurements to evaluate water splitting performance.
• Density Functional Theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• The WO3/NiSe2 photoanode achieved a photocurrent density of 1.66 mA cm-2 at 1.23 V vs RHE, a seven-fold increase over pristine WO3.
• DFT calculations revealed a lower Gibbs free energy for the oxygen evolution reaction on the WO3/NiSe2 heterostructure.
• The hybrid catalyst exhibited 94.4% Faradaic efficiency for hydrogen generation and good stability.

Conclusions:

• The WO3/NiSe2 heterojunction significantly enhances charge carrier separation and transfer for efficient PEC water splitting.
• This work presents a viable strategy for designing advanced photoanodes for solar fuel production.