Enhanced photo-electrochemical activity of ZnO/Cu2S nanotube arrays photocathodes

ZnO/Cu 2 S nanotube arrays are fabricated firstly by a facile and capping-agent-free method, and the photo-electrochemical performance has been studied systematically. The results show that ZnO/Cu 2 S nanotube arrays achieve enhanced photo-electrochemical water splitting performance and the photocurrent densities of ZnO/Cu 2 S are 7.9 times than that of ZnO at 0 V versus Ag/AgCl. The performance of the ZnO/Cu 2 S nanotube arrays can be adjusted by changing the amount of Cu 2 S microcrystals. The results confirm that the enhanced photo-electrochemical performance of ZnO/Cu 2 S is due to the significantly improved visible light absorption, effective separation of photo-induced carriers due to the well band energy match and the formed p-n junction between ZnO and Cu 2 S.