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

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.