Au Cu alloys deposited on titanium dioxide nanosheets for efficient photocatalytic hydrogen evolution

Abstract This work first reports Au Cu alloys deposited on the surface of TiO 2 nanosheets (TiNs) to form heterojunction. A simple deposition-precipitation method was used to construct a new type of Au Cu/TiNs heterostructures through gradually depositing Au and Cu nanoparticles on TiNs. Such structures served the dual advantage of constructing a heterostructure which can improve visible light absorption, and the formation of a Schottky barrier between Au Cu alloys (lower Fermi level) and TiNs (higher Fermi level) which can suppress the recombination of photo-generated charge carriers to improve the overall photocatalytic activity. The mass ratio of Au and Cu in the Au Cu/TiNs heterostructures and the sequence and method of their deposition are found to be the important factors which affect the photocatalytic performance. When the mass ratio of Au to Cu was determined to be 1: 1, the Au Cu/TiNs heterostructure exhibited the best photocatalytic performance for hydrogen production from water splitting (over 9 times than TiNs, 1.47 times than Au/TiNs, and 1.75 times than Cu/TiNs).