Hydrogen bonded metal–organic supramolecule functionalized BiVO4 photoanode for enhanced water oxidation efficiency

Hydrogen bonded metal–organic supramolecules are a new family of cocatalysts for high-efficiency water oxidation photoanodes owing to their suitable electrical conductivity. We herein designed a calix [4] resorcinarene-based metal–organic supramolecular system with rich hydrogen bonds, namely [Cu2L(H2O)2]∙3DMF (L = calix [4] resorcinarene-based ligand and DMF = N,N’-dimethylformamide) or Cu2L. Then, the hydrogen bonded metal–organic supramolecular system was applied as a cocatalyst in BiVO4 nanoplate photoanode for water oxidation reaction. Photoelectrochemical and electrochemical analysis demonstrated that the obtained Cu2L-modified BiVO4 photoanode showed greatly enhanced water oxidation efficiency, which was about three times higher than bare BiVO4 nanoplates. In addition, photoelectrochemical activity was well maintained within three hours. Cu2L as an efficient cocatalyst can promote the holes on the surface of the photoanode to participate in the oxygen evolution reaction, thus improving the performance of the photoanode. This work presents a feasible strategy by using the hydrogen bonded metal–organic supramolecular system to functionalize photoanodes for enhanced water oxidation efficiency.