Active Co/Fe composite oxide nanoparticles for efficient photocatalytic hydrogen production

As energy depletion and environmental pollution problems become more and more serious, people have to turn their attention to cleaner and environmentally friendly hydrogen energy. Hydrogen production by photolysis of water is an economical and clean and ideal way to obtain hydrogen energy. The conversion of solar energy into chemical energy by photocatalytic means is also a promising technical means. However, how to choose an efficient and economical photocatalyst is the most critical link in hydrogen production. Transition metal-based materials generally have potential photocatalytic activity and good stability and are rich in resources, low in price, and environmentally friendly. They are photocatalytic materials with competitive advantages. Therefore, in this study, Co/Fe oxide nanoparticles are prepared by simple electroconversion method and compared with pure oxides Co3O4, Fe2O3, and Fe3O4 prepared by electroconversion as photocatalytic catalysts for hydrogen evolution. The results of material characterization show that the Co/Fe composite oxides prepared by electroconversion are Co3O4/Fe2O3 and CoFe2O4. The photocatalytic results show that Co3O4/Fe2O3 has the best hydrogen evolution rate (100.47 mmol/g·h) because Co3O4/Fe2O3 forms a p–n heterojunction with the smallest band gap energy and its catalytic mechanism is discussed.