Sonochemical synthesis and characterization of CuInS2 nanostructures using new sulfur precursor and their application as photocatalyst for degradation of organic pollutants under simulated sunlight

In this research, we investigated the photocatalytic activity of CuInS₂ nanoparticles in visible light during the decomposition of three toxic dyes (Eriochrome Black T, Rhodamine B, and Erythrosine). The CuInS₂ nanostructures were synthesized by a rapid and simple sonochemical method using dithiooxamide as a sulfur reagent and various capping agents, including SDS, CTAB, and PVP, were applied to achieve a pure structure with fine morphology. The flower-like structure was observed through FESEM images, implying different capping agents and fabrication had a considerable influence on the morphology of samples. The suitable bandgap of CuInS₂ (1.53 eV) was obtained from DRS analysis and resulted in higher photodegradation efficiency. The fabricated CuInS₂ revealed better photodegradation efficiency (74.8%) to the anionic dyes than cationic dye. A possible photodegradation mechanism was suggested based on scavenger tests of active species.