Simple Fabrication of SnO 2 Quantum-dot-modified TiO 2 Nanorod Arrays with High Photoelectrocatalytic Activity for Overall Water Splitting.

Photoelectrochemical (PEC) water splitting has been demonstrated as a promising way to acquire clean hydrogen energy. However, the efficiency has been limited by the high recombination rate of photogenerated electron-hole pairs. Herein, we provided a simple approach to construct a novel SnO2 quantum dots (QDs) modified TiO2 nanorod arrays (NAs) by the calcination of SnCl2 -adsorbed TiO2 NAs. The photocurrent density of SnO2 QDs/TiO2 NAs exhibits about 5 times higher than that of parent TiO2 NAs at a bias of 0.4 V vs. Ag/AgCl. SnO2 QDs/TiO2 NAs also show a high photoelectrocatalytic activity for overall water splitting with an actual yield of H2 and O2 to be 27.85 and 11.87 μmol cm-2  h-1 , respectively. The excellent performance of photoanode for PEC water splitting could be attributed to its Z-scheme heterostructure for good separation efficiency and transport rate of photogenerated charge carries.