Insight into the adsorption and photocatalytic properties of in-situ synthesized g-C3N4/SnS2 nanocomposite

In this paper, a novel g-C3N4/2 wt% SnS2 nanocomposite was successfully synthesized using an in-situ growth of SnS2 on g-C3N4. X-ray diffraction (XRD), atomic force microscopy (AFM), Brunauer-Emmett-Teller (BET) method, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectrometer were used to characterize the photocatalysts. Exploring adsorption behavior, as an importatnt stage during photocatalytic reactions, is of great importance. Hence, both adsorption and photocatalytic performance of the synthesized photocatalysts have been investigated in detail. The adsorption isotherm fittings exhibited that Freundlich and Langmuir-Freundlich models can be applied to the methylene blue (MB) adsorption on the photocatalysts, indicating surface heterogeneity should be considered. A pseudo-second-order model was fitted to explore the adsorption kinetics. According to the observed redshift in the Fourier transform infrared spectroscopy (FTIR) result of g-C3N4/SnS2 nanocomposite, pi-pi interaction was dominant during MB adsorption. Also, a slight redshift and significant PL intensity reduction in g-C3N4/SnS2 nanocomposite led to 96% photocatalytic efficiency after 180 min under visible light radiation. The kinetics of photodegradation over g-C3N4/SnS2 was about 9 and 3 times higher than those of g-C(3)N(4 )and SnS2 photocatalysts, respectively. The superoxide and hydroxyl radicals were the main reactive species in the photocatalytic degradation with a Z-scheme charge transfer mechanism. The g-C3N4/SnS2 nanocomposite was found to be remarkably stable after three consecutive cycles of MB degradation.

Automated summary

In this study, a novel g-C3N4/2 wt% SnS2 nanocomposite was successfully synthesized using an in-situ growth method. The synthesized photocatalysts were characterized using various techniques, and their adsorption and photocatalytic performance were investigated. The results showed that the nanocomposite exhibited high photocatalytic efficiency under visible light radiation, and it remained stable after multiple cycles of degradation.