Upgrading the Optical and Catalytic Efficiency of CuCo2O4 Nanostructures via Composing with CuS or CdS for Hydrogen Generation

Abstract The present work examines the efficacy of CuCo2O4, CuCo2O4/CuS or CuCo2O4/CdS as catalysts for hydrogen generation via NaBH4 hydrolysis. CuCo2O4, CuCo2O4/CuS and CuCo2O4/CdS nano samples were produced using hydrothermal and thermolysis techniques. X-ray diffraction (XRD) data manifested a single phase for all samples implying that the Cu, Cd, and S ions are integrated within the CuCo2O4 lattice, thereby forming a solid solution. Structure and microstructure analyses for all samples was performed using Rietveld analysis. The obtained UV–Vis diffuse absorbance revealed an enhanced visible light absorption for the 0.95CuCo2O4/0.05CuS sample. The CuCo2O4 sample possesses two optical band gaps (1.6, 2.1) eV. These bandgaps increased for the CuCo2O4/0.05CdS sample (1.66, 2.29) eV but decreased for CuCo2O4/0.05CuS sample (1.69, 1.87) eV. The catalytic effectiveness of CuCo2O4, CuCo2O4/CuS or CuCo2O4/CdS samples in promoting the hydrolysis of NaBH4 under natural daylight circumstances in the laboratory was evaluated. The production rate of hydrogen using CuCo2O4/0.05CuS is nearly double that for pure CuCo2O4 and more than four times that of NaBH4 self-hydrolysis. The activation energy of CuCo2O4 and of CuCo2O4/0.05CuS towards NaBH4 were calculated to be 71.42 and 58.37 kJ/mol, respectively.