Dual purpose of graphene decorated with Cu3SnS4 as a counter electrode for dye sensitized solar cells and degradation of tetracycline antibiotics

Abstract

This article describes the synthesis of a series of Cu₃SnS₄/graphene composites using a simple one-pot solvothermal technique. XRD, SEM, TEM, Raman, UV–visible absorption, PL, and N₂ adsorption-desorption isotherms characterised sample structure, morphology, optical characteristics, and porosity. XRD and TEM examinations show that Cu₃SnS₄ has a tetragonal crsyalline structure with spherical nanoparticles of 30–35 nm equally distributed over graphene sheets.. The band gap was determined to be 3.35, 3.12, 2.92, and 2.63 eV for Cu₃SnS₄, CSSG1, CSSG2, and CSSG5 CEs, respectively. CSSG5 CEs exhibits strong SSA (117.5 m²/g and 36.4 nm) and PS, which are about 2.2 times higher than those of pure Cu₃SnS₄ (52.3 m²/g and 13.4 nm). As a result, the DSSC equipped with Cu₃SnS₄/graphene (50 mg) nanocomposite CE achieved a power conversion efficiency (PCE) of 10.21 %, which was higher than that of using Cu₃SnS₄ nanoparticles (4.22 %) and comparable to the 5.91 % obtained with pure Pt CE as a reference. The nanohybrid structure of catalyst-active Cu₃SnS₄ nanoparticles established on electrically conducting 2D graphene sheets provides fast ion diffusion pathways, a large accessible surface area, and superb chemical and thermal stability, improving the electrode's performance. This research offers an alternative CE in non-Pt system materials and a better solution in other fields. Moreover, the CSSG5 sample showed high degradation percentage (95 %), rate constant (0.5612 min^-1) and long-term stability towards tetracycline (TC) under visible light irradiation.