Boosted visible-light photocatalytic performance of Au/BiOCl/BiOI by high-speed spatial electron transfer channel

Abstract

To improve the visible-light photocatalytic performance of BiOI, it is extremely desired to boost charge transfer and separation. Herein, a novel ternary Au/BiOCl/BiOI photocatalyst with enhanced separation efficiency and prolonged lifetime of photogenerated carrier was successfully in-situ prepared via a facile thermal reduction method. The Au nanoparticles uniformly distributed on BiOI and BiOCl acted as an electron-bridge, which could promote the transfer of electron from BiOI to BiOCl, forming a high-speed spatial electron transfer channel. In addition, BiOCl provided a high-energy-level platform to prolong charge lifetime by receiving high-energy electrons of BiOI to alleviate the relaxation to the valence band and recombination with the holes on the valence band. The synergistic effect of Au and BiOCl largely improved the separation efficiency of BiOI photogenerated carrier, ultimately the photocatalytic performances of Au/BiOCl/BiOI nanocomposites for RhB degradation in static system (97%) and dynamic system (85.52%) and NO removal (65.4%) were enhanced by 1.52, 1.71 and 1.32 times compared to BiOI, respectively. Thus, this work can provide new insights into understanding the important role of electron-bridge in accelerating electron transfer and designing the suitable high-energy-level platform to prolong charge lifetime.