Galvanic synthesis of Cu2−XSe thin films and their photocatalytic and thermoelectric properties

Abstract Cu 2− X Se thin film with cubic berzelianite phase was prepared by a simple, low-cost two electrode electrochemical technique and the photocatalytic and thermoelectric properties of the thin films were investigated. The results showed that Cu 2− X Se crystallized in the cubic berzelianite phase and found to possess both direct and indirect band gaps of 2.9 and 1.05 eV respectively, covering almost the entire range of solar-spectrum. The photocatalytic discoloration of aqueous methylene blue (MB) and rose-bengal (RB) dyes over Cu 2− X Se thin films were investigated under visible light irradiation. Cu 2− X Se thin films showed higher catalytic activity for MB compared to RB in presence of H 2 O 2 . The photocatalytic discoloration followed first-order reaction kinetics. Complete removal of aqueous MB was realized after visible light irradiation for 150 min with Cu 2− X Se thin film catalyst in presence of H 2 O 2 . Thermoelectric performances through power factor and figure of merit have been evaluated. Carrier concentration obtained from thermoelectric power was used to evaluate the mobility of carriers from electrical conductivity measurement.