Enhanced photoelectrochemical water splitting performance using morphology-controlled BiVO₄ with W doping

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Nanostructures offer advantages for solar-to-energy conversion, including improved carrier collection and light capture.
• Bismuth vanadate (BiVO4) is a promising photoanode material, but its efficiency can be limited by charge separation and interfacial transfer.
• Tungsten doping (W-BiVO4) is known to enhance the photoelectrochemical properties of BiVO4.

Purpose of the Study:

• To synthesize morphology-controlled W-doped BiVO4 thin films by adjusting solvent ratios.
• To compare the photoelectrochemical performance of planar and porous W-doped BiVO4 structures.
• To investigate the role of nanostructure morphology in enhancing solar-to-energy conversion efficiency.

Main Methods:

• Synthesis of W-doped BiVO4 thin films with varying morphologies (planar and porous) via precursor solution tuning.
• Characterization of film morphology and optical properties.
• Photoelectrochemical performance testing and quantitative analysis of performance-enhancing factors.

Main Results:

• Morphology-controlled W-doped BiVO4 films were successfully synthesized by tuning solvent ratios.
• Porous W-doped BiVO4 films exhibited increased surface area and enhanced light absorption compared to planar films.
• The porous structure demonstrated a 50% enhancement in photoelectrochemical performance, attributed to improved light absorption (13%), charge separation (14%), and interfacial charge injection (20%).

Conclusions:

• Tuning solvent ratios in precursor solutions is an effective method for controlling W-doped BiVO4 nanostructure morphology.
• Porous W-doped BiVO4 nanostructures significantly outperform planar structures in photoelectrochemical applications.
• The enhanced performance of porous W-doped BiVO4 is a result of synergistic improvements in light absorption, charge separation, and interfacial charge injection.