Wet chemistry synthesis of CuFe2O4/CdSe heterojunction for enhanced efficient photocatalytic H2 evolution under visible irradiation

Abstract

A heterostructure of CuFe2O4/CdSe was synthesized as H2 evolution photocatalyst under visible light. The optical absorption onset of the CuFe2O4/CdSe heterostructures was red-shifted to 2.30–2.48 eV, compared to that of the bare CuFe2O4 (2.55 eV), leading to better utilization of visible light. Furthermore, the CuFe2O4/CdSe samples exhibited a higher specific surface area than the bare CuFe2O4, due to the introduction of CdSe nanospheres. Compared to the bare CuFe2O4, the CuFe2O4/CdSe heterostructure promoted H2 production from water splitting. The enhanced photocatalytic performance of the CuFe2O4/CdSe catalyst was attributed to the more efficient charge separation and lower charge transfer resistance, confirmed by fluorescence decay measurements and Nyquist plots, respectively. The band alignment between CuFe2O4 and CdSe resulted in an interfacial p-n junction, which directed the electron transfer from CdSe to CuFe2O4 and the hole transfer from CuFe2O4 to CdSe, achieving improved spatial separation of charge carriers.