Synthesis of lead-free Cu/CuFeO2/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 a high efficiency value of 25.44% using Cu/CuFeO 2 (delafossite)/CZTS (Cu 2 ZnSnS 4 , kesterite) as an investigated photocatalyst. The X-ray diffraction (XRD) analysis of the investigated photocatalyst (Cu/CuFeO 2 /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/CuFeO 2 /CZTS, Cu/CuFeO 2 , 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/CuFeO 2 /CZTS. The photoelectrochemical (PEC) performance of the investigated photocatalyst for hydrogen (H 2 ) generation was examined in wastewater. The current–time characteristic and the PEC behavior of Cu/CuFeO 2 /CZTS in dark and under light illumination using various power densities, monochromatic wavelengths, and different temperatures were studied. The current densities (J Ph ) under light illumination and (J o ) in the dark were − 8.0 and − 0.7 mA cm −2 , respectively. The H 2 generation rate for the Cu/CuFeO 2 /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 energy production and the hindrances of sewage treatment at the same time.