Anchoring AuCu alloy nanoparticles on TiO2 nanosheets: exploiting synergistic effects and directed electron transfer for enhanced photocatalytic H2 evolution

Abstract

AuCu/TiO2 composite photocatalysts were prepared by anchoring AuCu nanoparticles (NPs) on TiO2 nanosheets using a simple photoreduction method. Visible diffuse reflectance spectra indicated that the AuCu/TiO2 significantly enhanced light absorption in the visible region. Through photoluminescence spectroscopy and steady-state surface photovoltage experiments, AuCu/TiO2 exhibits an excellent photogenerated electron transfer rate. In addition, photoelectrochemical experiments showed that AuCu/TiO2 had a high photogenerated charge separation efficiency. AuCu/TiO2 (1.0 wt%) exhibited the best performance, under full spectrum, the hydrogen evolution rate is 33.94 mmol g−1 h−1, which is 1.59 times and 1.66 times higher than that of single metal Au/TiO2 (1.0 wt%) (21.28 mmol g−1 h−1) and Cu/TiO2 (1.0 wt%) (20.42 mmol g−1 h−1), respectively. The results showed that AuCu NPs greatly enhanced the photocatalytic performance of the composite photocatalysts.