Amorphous Double Cocatalyst Enhanced BiVO₄ Photoanode for Efficient Solar-Driven Water Splitting

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Photoelectrochemical (PEC) water splitting is crucial for addressing energy and environmental concerns.
• Developing efficient photoanodes is key to advancing PEC technology.

Purpose of the Study:

• To create a novel BiVO4/FeOOH/CACo photoanode for enhanced PEC water splitting.
• To investigate the synergistic effects of FeOOH and cobalt cinnamate (CACo) cocatalysts.

Main Methods:

• Fabrication of a BiVO4 photoanode integrated with FeOOH and CACo cocatalysts.
• Performance evaluation using photocurrent density measurements and stability tests.
• Analysis of hydrogen and oxygen production rates in seawater.
• Characterization techniques and density functional theory (DFT) calculations.

Main Results:

• The BiVO4/FeOOH/CACo photoanode achieved a photocurrent density of 3.15 mA cm⁻² at 1.23 VRHE, 3.15 times higher than pure BiVO4.
• Demonstrated good stability and significant hydrogen (4.71 μmol h⁻¹ cm⁻²) and oxygen (2.87 μmol h⁻¹ cm⁻²) production rates in seawater.
• DFT calculations confirmed FeOOH as a hole transport layer and revealed synergistic effects suppressing recombination and enhancing carrier mobility.

Conclusions:

• The dual cocatalyst system of FeOOH and CACo on BiVO4 effectively enhances PEC water splitting.
• The strategy suppresses electron-hole recombination and improves photogenerated carrier migration.
• This work presents a viable approach for employing amorphous cocatalysts in PEC systems for clean hydrogen production.