▎ 摘　　要

The sandwich-like Z-scheme g-C3N4/reduced graphene oxide@TiO2 (CN/RGO@T) composite with enhanced photocatalytic performance was successfully synthesized by hydrothermal method followed by a calcination process. It is interesting to note that TiO2 completely enclosed by RGO is presented in a nanoscroll morphology. Photocatalytic performance of the composite was evaluated in the propylene degradation. The results revealed that by introducing RGO as an interfacial mediator, Z-scheme g-C3N4-TiO2 nanocomposites could remarkably speed up the interfacial charge transmission and improve the separation efficiency of photogenerated carriers. Especially, 20%CN/RGO@T composite showed the highest visible light activity up to 21.9% for propylene oxidation. A lower photogenerated electron-hole recombination rate and higher carrier separation efficiency of the ternary complex 20%CN/RGO@T were confirmed by electron spin resonance, photoluminescence spectrum, and photocurrent-time characterization. This is due to the fact that strong pi-pi interaction between g-C3N4 and RGO leads to a carrier transmission channel between N-O and C-O-C bonds of g-C3N4 and RGO. This newly formed Z-scheme composite is having a possibility to be explored as a versatile photocatalyst to conduct various type photoreactions.