Photocatalytic performance of SnS2 nanoflakes synthesized through a facile reflux method

Developing an effective yet convenient synthesis method to achieve visible light-responsive metal sulfides has been one of the main challenges in the photocatalysis field. In this study, a facile reflux approach has been proposed to synthesize SnS2 nanoflakes for photocatalytic degradation of methylene blue (MB) as an organic pollutant. X-ray diffraction (XRD) pattern and Raman spectroscopy confirmed the formation of SnS2 with hexagonal crystal structure. The results of the nitrogen (N2) adsorption-desorption were analyzed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. BET results exhibited specific surface area, total pore volume, and average pore diameter of 84.3 m2/g, 0.22 cm3/g, and 10.3 nm, respectively. The BJH outcomes indicated a distribution of about 40 nm for pore size with a peak of 1.64 nm. The nanoflake morphology and band gap energy of approximately 2.15 eV were revealed through field emission electron microscope (FESEM) and diffuse reflectance spectroscopy (DRS), proving the successful synthesis of visible light-responsive SnS2 nanoflakes. The efficiency of MB photodegradation over SnS2 nanoflakes was 78% under visible light radiation. The photocatalytic reaction followed a pseudo-first-order kinetic model with the calculated rate constant of 0.0045 min-1. Additionally, the photocatalytic degradation mechanism over SnS2 nanoflakes was investigated, and the results proved the successful contribution of holes and hydroxyl radicals in the mineralization of MB.