Copper sulfide films obtained by spray pyrolysis for dyes photodegradation under visible light irradiation

Thin films of CuxS were deposited by robotic spray pyrolysis technique, at T = 300 °C, using 20–50 spraying sequences, from water:ethanol:glycerol = 7:2:1 (in volumes) precursor solutions with molar ratio Cu:S = 1:2.5–3.5. Relative homogenous and uniform films of CuxS (x = 1.8, 2), with 321–571 nm thickness, granular morphology and Eg = 2.11–2.78 eV were obtained. The photocatalytic activity of the films was evaluated based on the degradation of methylene blue in aqueous solution containing H2O2, under visible (VIS) light irradiation. Efficiencies of 90–99% and 84–89%, after 4 and 12 h, respectively, under visible light irradiation, showed that CuxS films are promising materials for organic pollutants (dyes) photodegradation.