Constructing an efficient p–n heterojunction photocatalyst CaFe2O4/Fe2O3 nanocomposite for degradation of methyl orange

As the global environment continues to deteriorate, a technology is urgently needed to eliminate the pollution caused by organic dyestuffs in the environment. Although nano-Fe2O3 photocatalyst has developed greatly in the field of organic degradation, until now, the degradation efficiency cannot satisfy the demands. This work addresses imperative need by constructing an efficient p–n heterojunction photocatalyst CaFe2O4/Fe2O3 nanocomposite for improving the methyl orange (MO) degradation efficiency of nano-Fe2O3. Here, the p-CaFe2O4/n-Fe2O3 nanocomposite was prepared by using the two-step process of hydrothermal method and co-precipitation. The degradation performance of as-developed nanocomposite was tested by altering the experimental parameters including different mass ratio of p-CaFe2O4 and n-Fe2O3, photocatalyst dosage, H2O2 volume, initial concentration of MO and pH, and degradation intermediates were analyzed by HPLC and MS. Experimental results indicated the degradation efficiency of prepared sample was up to 99% at 60 min under the optimized conditions, meanwhile, it showed high removal ability after five repeated utilizations. Furthermore, the photocatalytic mechanism was systematically explored based on degradation intermediates. Overall, the nanocomposite photocatalyst was not only designed with using cheap and abundant materials via a simple route, but also exhibited outstanding photocatalytic activity, which will supply a new possibility to effectively deal with the large volume organic pollutants from the textile industry.