Artificial all-solid-state system by RGO bridged Cu2O and Bi2WO6 for Z-scheme H2 production and tetracycline degradation.

With the development of visible-light-driven photocatalytic systems, the Z-scheme system has been paid more attention for water-splitting and contaminants degradation in an effort to the full utilization of superior band potential between two different semiconductors. Here we present systemic investigation of the reduced graphene oxide (RGO)-based composites, including RGO-Cu 2 O, RGO-Bi 2 WO 6 , RGO-Cu 2 O/Bi 2 WO 6 , Cu 2 O/Bi 2 WO 6 heterojunction and physical mixed RGO + Cu 2 O + Bi 2 WO 6 , to give a clear demonstration of the Z-scheme photocatalytic mechanism. The three-component RGO-Cu 2 O/Bi 2 WO 6 composite showed the highest photocatalytic activity on water splitting, which is about 3 times and 4 times that of RGO-Cu 2 O and Cu 2 O respectively. And it also exhibited an excellent photocatalytic performance with a 86% degradation rate for tetracycline that is about 3 (6) times as high as that of pure Cu 2 O (Bi 2 WO 6). These results demonstrate that the construction of RGO-Cu 2 O/Bi 2 WO 6 Z-scheme system is beneficial to water splitting and pollutant degradation for which the superior band potential of Cu 2 O and Bi 2 WO 6 are fully utilized. This work not only reports a new Z-scheme system of RGO-Cu 2 O/Bi 2 WO 6 but also provides a guide to the design of RGO-based photocatalysts. [ABSTRACT FROM AUTHOR]