Abstract
•TiO2 NBs/Cu2S composite structure prepared via hydrothermal and SILAR method.•The products can be used for efficient photoelectrochemical water splitting devices.•High performance was obtained due to the absorption spectra and band structure.
Hierarchical nanostructured TiO2 is known to be ideal materials for photoelectrochemical water splitting because of its excellent light harvesting efficiency, efficient charge separation and transport properties. In the present work, rutile TiO2 nano-branched arrays (NBs) were grown directly on transparent conductive glass (FTO) using a simple two-step hydrothermal method. TiO2 NBs/Cu2S composite structure was subsequently synthesized through successive ionic layer adsorption and reaction (SILAR). Detailed growth mechanisms for TiO2 NBs nanostructure and TiO2 NBs/Cu2S composite structure were discussed. The optical property of composite structures was characterized, and enhanced absorption spectrum was discovered. A much higher hydrogen generation efficiency of 13.15% at 0.70V versus Ag/AgCl electrode was achieved for this TiO2 NBs/Cu2S composite structure. This is attributed to the improved light absorption and appropriate energy gap structure, which is over 40% higher than that of TiO2 NWs/Cu2S composite structure.