Synthesis of CuInS2 thin film photocathode with variation of sulfurization sources and Pt-In2S3 modification for photoelectrochemical water splitting

Abstract

CuInS₂ thin films have been successfully synthesized from the electrodeposition of copper (Cu), indium (In), and sulfurization on a molybdenum glass substrate as a water splitting photocathode. The effect of various sources of sulfurization with thiourea, sulphur, and H₂S and modification with Pt-In₂S₃ on the character and performance of the material was observed. The success of the synthesis was confirmed by the typical peaks of 28.2, 46.8, and 55.4° on XRD, the presence of Cu, In, S elements on SEM-EDX analysis, the appearance of peaks of 298 cm⁻¹ on Raman analysis, and the detection peaks of Cu 2p, In 3d, and S 2p with XPS analysis. Meanwhile, performance effectiveness and photoelectrochemical properties were analysed with photocurrent linear sweep voltammetry (LSV), applied bias photon-to-current efficiency (ABPE), and incident photon-to-current conversion efficiency (IPCE). Variations of sulfurization sources give different character and photocurrent results due to differences in the existing reaction mechanisms. While the modification treatment with Pt-In₂S₃ increased the resulting photocurrent. Sulfurization with H₂S and modification of Pt-In₂S₃ gave the best results with a photocurrent of 18 mA cm⁻², an efficiency of 3% ABPE, 47.2% IPCE, was evolved 467 μmol H₂ and 230,1 μmol O₂. This shows good potential as a water splitting material to produce environmentally friendly hydrogen fuel.