Chemically derived quinary Cu2Co1–xNaxSnS4 photon absorber material and its photocatalytic application

Abstract The solar absorbing materials attract attention for the opto-electronic device applications such as solar cells and photocatalysis. Interest in photocatalytic materials to clean up the wastewater has started to increase. Generally, semiconductors sensitive to UV region are used. However, most of the light from the sun is in the visible region. Cu 2 CoSnS 4 is a promising material that exhibits superior photo-response in the visible regions with an appropriate band gap. In this study, Cu 2 CoSnS 4 films were prepared by the sol–gel method. Cu 2 Co 1–x Na x SnS 4 was synthesized for the first time by partly substituting sodium with cobalt. With this approach, noticeable improvements were observed in the physical properties of the material. With the sodium replacement, the Cu 2 Co 1–x Na x SnS 4 exhibited high photocatalytic performance toward the degradation of methylene blue (MB) under visible-light irradiation. According to the results, Cu 2 CoSnS 4 and Cu 2 Co 1–x Na x SnS 4 samples degraded the MB solution by degradation efficacy values of 89.69% and 94.57%, respectively, in a short time like 40 min under visible light. This study shows that the substitution of sodium boosted the degradation efficiency by 5.4%. For the Cu 2 CoSnS 4 and Cu 2 Co 1–x Na x SnS 4 samples, the computed reaction rate constants are 0.059 min −1 and 0.077 min −1 , respectively.