In situ formation of a Co-MOF/Ti–Fe2O3 photoanode for efficient photoelectrochemical water splitting†

As a promising approach to convert solar energy into a low-cost form, photoelectrochemical (PEC) water splitting is attracting a lot of attention from researchers. However, the PEC hydrogen production is limited by the oxygen evolution reaction. Therefore, it is necessary to find effective means to accelerate the water oxidation kinetics of photoanodes. In this work, a Co-MOF cocatalyst was modified onto Ti–Fe₂O₃ photoanodes using a simple hydrothermal method, which allowed greater adsorption and exposure of cobalt species with high catalytic activity. The composite photoanode Co-MOF/Ti–Fe₂O₃ demonstrates a higher photocurrent density of 3.9 mA cm⁻² at 1.23 V vs. RHE, promoting water oxidation kinetics and the transfer of photogenerated carriers. This work provides an effective approach for constructing high-performance photoanodes using metal–organic framework materials.