A competitive candidate for the Cu<sub>2</sub>ZnSnS<sub>4</sub> compound in solar photocatalytic degradation of organic pollutants

This study focused on preparing and analyzing two sulfide compounds: Cu2ZnSnS4 and Cu2BiSnS4, in order to assess their effectiveness in breaking down pollutants using solar radiation as a photocatalyst method. The results indicated the formation of crystalline phases for both compounds with variations in crystal lattice parameters while closely matching the desired composition ratios. The research also highlighted a nanoparticle morphology with variances in nanoparticle size and distribution observed between the two compounds. The results indicated that both compounds possess an energy gap falling within the visible light spectrum and are thus capable of absorbing radiation effectively. Enough tests under sunlight for photocatalytic purposes demonstrated a superior performance in breaking down organic pollutants with methyl green dye, achieving an 82% degradation efficiency in the Cu2BiSnS4 compound compared to the Cu2ZnSnS4 compound, which exhibited a photodegradation efficiency of 75%, over a similar exposure duration. The distinct disparity in efficiency between the two compounds is from differences in the size and shape of the nanoparticles as well as their distribution and surface characteristics, influencing the movement of charge carriers and light absorption dynamics. According to the findings, the authors suggest that Cu2BiSnS4 shows potential as a catalyst for solar photocatalysis applications due to its unique optical and structural properties, making it an asset in the development of environmentally friendly solutions for water purification and mitigation of environmental pollutants.