Interface-induced efficient adsorption and photocatalytic degradation of organic pollutants using rGO/SnO2 nanocomposites: exploring the role of rGO concentration at the interface

Abstract

This study presents the synthesis and characterization of rGO/SnO2 nanocomposites and investigates their efficacy in the adsorption and photocatalytic degradation of organic contaminants. The nanocomposites were synthesized via a one-step hydrothermal route, which is an environmentally friendly method without the use of hazardous reducing agents. The incorporation of rGO onto SnO2 nanostructures led to bandgap modification and increased specific surface area, synergistically enhancing the adsorption and photocatalytic properties of the nanocomposites. The influence of varying rGO concentrations on the performance of the nanocomposite was systematically examined. An optimal weight ratio of 15% of rGO was identified, providing the most effective adsorption-photodegradation synergy, resulting in the rapid degradation of organic contaminants under simulated sunlight irradiation. The nanocomposites demonstrated high degradation rates for a mixture of rhodamine B (RhB) and methylene blue (MB) dyes within 50 min. Scavenger experiments identified superoxide anion radicals (O 2 •−) and hydroxyl free radicals (OH•) as the primary active species involved in the photocatalytic degradation process. Furthermore, the study explored the influence of initial dye concentration and photocatalyst mass under optimized conditions. The interfacial contact between rGO nanosheets and SnO2 nanostructures played a crucial role in enhancing the photocatalytic performance by facilitating efficient charge carrier separation. The results indicated the efficient degradation of high concentrations of dyes and demonstrated the potential of rGO/SnO2 nanocomposites for real-world wastewater treatment applications. Overall, this study highlights the remarkable adsorption-photocatalytic synergy of rGO/SnO2 nanocomposites, offering a promising solution for the simultaneous degradation of mixed organic contaminants.