Insights into the development and performance of CuO/CuFe2SxO4−x catalysts: an effective approach for renewable hydrogen generation

Abstract

Hydrogen is an ideal alternative to fossil fuels owing to its renewable, carbon-free, high-energy-mass, and sustainable nature. The aim of this study was to develop a cost-effective and sustainable approach for green fuel (H₂) production. To achieve this objective, CuO/CuFe₂S_xO_4−x catalysts were synthesized and employed for photoreaction to generate hydrogen. For achieving progressive results, a hydrothermal approach was used to synthesize the catalysts. XRD analysis confirmed that sulphur doping causes lattice strain through the incorporation of larger sulphur anions. SEM results revealed that sulphur doping has reduced agglomeration to increase active sites for hydrogen evolution. Electrochemical and photoluminescence studies demonstrated that presence of sulphur dopants and CuO promote charge separation and transfer of photogenerated charges to the reaction sites and facilitate water reduction reactions for H₂ production. Moreover, the CuO content improved the oxidation potential of CuFe₂S_xO_4−x catalysts. EDX and XPS analyses verified the elemental compositions and oxidation states of the catalysts, while VSM and EPR results confirmed the improved magnetic and electronic properties that are expected to enhance the photocatalytic activity. Overall, CuO/CuFe₂S_xO_4−x generated 7.45 mmol g⁻¹ h⁻¹ of hydrogen with an AQY of 2.45%, that was five times higher than pristine CuFe₂O₄. On the basis of results, it could be concluded that CuO/CuFe₂S_xO_4−x catalysts can potentially be utilized for green fuel (H₂) generation applications.