Synthesis of g-C3N4/diatomite/MnO2 composites and their enhanced photo-catalytic activity driven by visible light

Herein, a novel visible-light-responsive g-C3N4/diatomite/MnO2 composite was successfully fabricated through a simple redox reaction method. The structure and morphology of the sample are mainly characterized by X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis). In this paper, the photo-catalytic activity of the sample was evaluated by degradation RhB under visible-light irradiation. The results shown that, compared with g-C3N4/diatomite composite, MnO2, g-C3N4, diatomite, the prepared g-C3N4/diatomite/2.5%MnO2 composite exhibits better photo-catalytic activity and stability. At the same time, the effect of different MnO2 additions on the photo-catalytic activity of the composite material was further analyzed. The results indicated that the g-C3N4/MnO2/diatomite composites exhibit highest photo-catalytic activity when the adding amount of MnO2 reached 2.5%. The degradation rate of the g-C3N4/diatomite/2.5%MnO2 is 93% after recycling for three times, showing good stability and reusability. Moreover, the mechanism of catalytic performance enhancement also has been discussed.

Automated summary

A novel visible-light-responsive g-C3N4/diatomite/MnO2 composite was successfully fabricated and showed superior photo-catalytic activity and stability, with the highest performance achieved at 2.5% MnO2 addition. The mechanism of catalytic performance enhancement was also discussed in the study.