Light-Driven Water Splitting with a Molecular Electroassembly-Based Core/Shell Photoanode

An electrochemical procedure for preparing chromophore-catalyst assemblies on oxide electrode surfaces by reductive vinyl coupling is described. On core/shell SnO 2 /TiO 2 nanoparticle oxide films, excitation of the assembly with 1 sun (100 mW cm –2 ) illumination in 0.1 M H 2 PO 4 – /HPO 4 2– at pH 7 with an applied bias of 0.4 V versus SCE leads to water splitting in a DSPEC with a Pt cathode. Over a 5 min photolysis period, the core/shell photoanode produced O 2 with a faradaic efficiency of 22%. Instability of the surface bound chromophore in its oxidized state in the phosphate buffer leads to a gradual decrease in photocurrent and to the relatively modest faradaic efficiencies.