Synthesis of lead-free Cu/CuFeO 2 /CZTS thin film as a novel photocatalytic hydrogen generator from wastewater and solar cell applications

Abstract The sewage water is tested as a source of hydrogen production with high efficiency value of 25.44% using Cu/CuFeO2 (delafossite)/CZTS (Cu2ZnSnS4, kesterite) as an investigated photocatalyst. The X-ray diffraction (XRD) analysis of the investigated photocatalyst (Cu/CuFeO2/CZTS) revealed a compact crystalline material as witnessed by the diffraction peaks with high intensities. From the optical characterization, the recorded band gap values of Cu/CuFeO2/CZTS, Cu/CuFeO2, and CZTS are 1.15, 1.97, and 1.43 eV, respectively, inferring an obvious enhancement in the optical properties of the investigated photocatalyst, Cu/CuFeO2/CZTS. The photoelectrochemical (PEC) performance of the investigated photocatalyst for hydrogen (H2) generation was examined in wastewater. The current-time characteristic and the PEC behavior of Cu/CuFeO2/CZTS in dark and under light illumination using various power densities or monochromatic wavelengths, and different temperatures were studied. The current densities (JPh) under light illumination and (Jo) in dark were − 8.0 and − 0.7 mA cm− 2, respectively. The H2 generation rate for Cu/CuFeO2/CZTS electrode was 0.049 mA/h. The thermodynamic parameters, respectively, ΔS*, ΔE, and ΔH* were 28.76 kJ mol− 1 K− 1, 21.0, and 18.28 kJ mol− 1 at 390 nm. The findings of the work hold great promise for addressing the energy production and the hindrances of sewage treatment at the same time.