Metal-oxide based Photoelectrode Materials for Water Splitting
In collaboration with the group of Prof. Christel Laberty-Robert ( UPMC) and Prof. Clément Sanchez (Collège de France), we develop facile and cost-effective methods for synthesizing photoactive metal-oxide photoanode materials such as α-Fe2O3 films. Mesoporous films can be fabricated by template-directed sol-gel chemistry coupled with the dip-coating approach, followed by annealing at high temperature. The photoelectrochemical performances of these photoanode materials can be further optimized through the deposition of co-catalyst. We recently demonstrated that undoped-hematite films heat-treated at relatively low temperature (500°C) achieve light-driven water oxidation under near-to-neutral (pH=8) aqueous conditions. The onset potential is 0.75 V vs the reversible hydrogen electrode (RHE), thus corresponding to 450 mV light-induced underpotential, and photocurrent density values reach 40 µA/cm2 for <1.1 V vs RHE. These new materials with a very large interfacial area in contact with the electrolyte and allowing for a high loading of water oxidation catalysts open new avenues for the optimization of Photo-Electro-Chemical water splitting.