Enhanced visible-light photocatalytic activity with Fe2O3–ZnO@C/g-C3N4 heterojunction: Characterization, kinetics, and mechanisms

Heterojunction photocatalysts Fe2O3–ZnO@C/g-C3N4 (FZCCN) were prepared by precipitation and calcination in this study. Systematic characterization demonstrated that the tight interfacial contact was established between Fe2O3–ZnO@C and g-C3N4, and the FZCCN-4 (theoretical mass ratios of ZnO and g-C3N4 was 4) had large BET surface area (110.136 m2 g−1). Bisphenol A (BPA) was selected to estimate the photocatalytic properties of FZCCN and the degradation reaction kinetics was analyzed at the same time. The results showed that, FZCCN-4 had the highest removal rate of BPA (100%, 60 min). The degradation rate of BPA by using FZCCN-4 was approximately 32 and 130 times higher than that of g-C3N4 and Fe2O3–ZnO@C, respectively. ·O2− was proved to be the main active species by capture experiment and electron spin resonance. The UV–vis and PL results proved the formation of heterojunction in FZCCN. This study also identified the intermediates of BPA degradation and tested their toxicity. The excellent visible light catalytic performance of Fe2O3–ZnO@C/g-C3N4 makes it an ideal material for degrading contaminants.