Visible light-responsive carbon-decorated p-type semiconductor CaFe2O4 nanorod photocatalyst for efficient remediation of organic pollutants

We report the fabrication and photocatalytic property of a composite of C/CaFe 2 O 4 nanorods (NRs) in an effort to reveal the influence of carbon modification. It is demonstrated that the photocatalytic degradation activity is dependent on the mass ratio of C to CaFe 2 O 4 . The optimal carbon content is determined to be 58 wt% to yield a methylene blue (MB) degradation rate of 0.0058 min −1 , which is 4.8 times higher than that of the pristine CaFe 2 O 4 NRs. The decoration of carbon on the surface of CaFe 2 O 4 NRs improves its adsorption capacity of the MB dye, which is specifically adsorbed on the surface as a monolayer according to the adsorption isotherm analysis. The trapping experiments of the reactive species indicate that superoxide radicals ( • O 2 − ) are the main active species responsible for the removal of MB under visible-light irradiation. Overall, the unique feature of carbon coating enables the efficient separation and transfer of photogenerated electrons and holes, strengthens the adsorption capacity of MB, and improves the light harvesting capability, hence enhancing the overall photocatalytic degradation of MB.