Fenton activity on RhB degradation of magnetic g-C3N4/diatomite/Fe3O4 composites

The g-C3N4/diatomite/Fe3O4 composites were synthesized by an electrostatic self-assembly method. The band edge of g-C3N4 was red shifted due to the addition of Fe3O4 and diatomite. Consequently, the visible light response of the composites was intensified. The decrease of the recombination efficiency of the electrons and holes lead to enhancement of the electron mobility. The results also showed that the photocatalytic performance of the g-C3N4/diatomite/Fe3O4 composites was improved versus pure g-C3N4. H2O2 was also added to the reaction system. In this way, the synergistic effect of photocatalysis and Fenton effect can largely improve the catalytic efficiency of the g-C3N4/diatomite/Fe3O4 composites. The composites are extremely easy to be collected in the presence of an external magnetic field, proving the good recyclability of the CN/DT/FO composites. More than 90% of the RhB can be degraded over the g-C3N4/diatomite/Fe3O4 composites after five recycling runs, indicating the good stability of the composites. The results also showed that the catalytic reaction would produce different active species and undergo different reaction mechanisms due to the existence of H2O2. Fenton activity experiments confirmed that O-center dot(2)- and (OH)-O-center dot were important active species.

Automated summary

The g-C3N4/diatomite/Fe3O4 composites were synthesized by electrostatic self-assembly method, showing improved photocatalytic performance and stability. The addition of H2O2 enhanced catalytic efficiency, while the composites can be easily collected with an external magnetic field, indicating good recyclability.