S-scheme heterojunction; 2-Mercaptobenzothiazole; Internal electric field; Theoretical calculation; N-GO assisted
The specific type S-scheme photocatalyst CeO2@N-GO/g-C3N4 was successfully constructed, and the best MBT degradation rate reached 100%, which is more than twice that of g-C3N4 and CeO2. The enhanced degradation performance is related to the introduction of N-GO, accelerating the electron transfer. Unique Ce4+ → Ce3+ conversion property enhances the carrier utilization, which improves the photocatalytic activity. Moreover, theoretical calculation results indicate the interfacial internal electric field (IEF) is formed between CeO2 ((200), (311) crystal planes) and g-C3N4 ((002) crystal planes) to enhance the delocalized ability of the charge carriers. Moreover, various analyzed means are employed to put forward in depth on MBT degradation and IEF-induced S-scheme over CeO2@N-GO/g-C3N4, such as differential charge proves the electron transmission path from CeO2 to g-C3N4 to significantly prolong its lifetime. The radical capture and ESR results show that •OH, •O2−, and h+ are the active species in the S-scheme photocatalytic system.