To develop low consumption and an environmentally friendly degradation technology for organic pollutants, micro-SiC/graphene composite materials were synthesized by photocatalytic reduction, and the composition and morphology of the prepared materials were characterized by XRD, FTIR, Raman spectroscopy, XPS, and SEM. Rhodamine B (RhB) was selected as the simulated pollutant to investigate the photocatalytic activity and stability of composite materials under visible light irradiation. The degradation mechanism was preliminarily discussed by active species capture experiments. Results show that the lives of photogenerated electron and photogenerated hole of SiC were prolonged when combined with graphene, which improved the photocatalytic activity and stability of composite materials. The degradation efficiency of RhB reached 92.7% with the composite material of SiC/graphene ratio (1:0.8) under 60 min irradiation, and the degradation process accorded with the first-order reaction kinetic equation. The contribution of main active species for photocatalytic degradation followed with a decreasing order of photogenerated hole (h+), superoxide anion radical (·O2-), photogenerated electron (e-), and hydroxyl radical (·OH).
Keywords: Rhodamine B (RhB); SiC; composite materials; graphene; photocatalytic degradation.