Fabrication of MOF-derived CoTiO3/g-C3N4 S-scheme heterojunction for photocatalyst wastewater treatment

The fabrication of heterojunction has been considered to be a promising approach to constructing effective photocatalysis systems. Herein, a series of CoTiO3/g-C3N4 heterojunctions denoted as CTO/CN-X were in-situ calcined by adjusting the weight percentage of the starting materials of core-shell Zif-67@TiO2 and melamine.The selection of Zif-67@TiO2 and melamine as starting materials merited a good dispersibility of CoTiO3 on the g-C3N4 sheets owing to the hydrogen bond interactions between melamine and functional groups from Zif-67@TiO2. Attractively, CTO/CN-2 exhibited an excellent methyl orange degradation activity under visible light irradiation (lambda > 420 nm). The degradation process was proved to be a first order kinetics with a kinetics constant of 0.990820.99082 h(-1), which was 38.1, 6.1 times that of g-C3N4 and CoTiO3, respectively. Further investigation reveals revealed that CTO/CN adopted a S-scheme charge transfer route that simultaneously acquire high redox ability and broaden solar energy utilization. This work provides a feasible heterojunction construction strategy by using MOFs as precursors. (c) 2022 Published by Elsevier B.V.

Automated summary

In this study, a series of CoTiO3/g-C3N4 heterojunctions denoted as CTO/CN-X were successfully prepared by adjusting the weight percentage of the starting materials. Among them, CTO/CN-2 exhibited excellent methyl orange degradation activity under visible light irradiation, with a significantly higher kinetics constant compared to g-C3N4 and CoTiO3. Further investigation revealed that CTO/CN adopted an S-scheme charge transfer route, resulting in high redox ability and broadened solar energy utilization. This work provides a feasible strategy for heterojunction construction using MOFs as precursors.