Photocatalytic activity evaluation of tetragonal CuFe2O4 nanoparticles for the H2 evolution under visible light irradiation

Abstract Copper ferrite (CuFe2O4) nanoparticles have been successfully synthesized via a citric acid-assisted sol–gel method. For comparison, CuFe2O4 materials were also fabricated by solid-state reaction and co-precipitation method. Techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis diffuse reflectance spectrum (UV–vis DRS) have been employed to characterize the as-synthesized CuFe2O4 products. The CuFe2O4 sample prepared by sol–gel approach is composed of almost uniform nanoparticles with a grain size of about 80 nm and crystallized in a tetragonal crystal phase structure. Moreover, the photocatalytic activity of the as-obtained CuFe2O4 has been evaluated based on the H2 evolution from aqueous oxalic acid solution under visible light irradiation. The effects of preparation routes, photocatalyst mass concentration, initial sacrificial reagent concentration and the durability of the as-obtained CuFe2O4 have been investigated in detail. The best result of the photocatalytic H2 evolution activity (1.72 mmol h−1 gcat−1) was obtained over the sol–gel synthesized CuFe2O4 nanoparticles when the photocatalyst concentration is 1.0 g l−1 and the oxalic acid concentration is 0.05 M.