Mechanically synthesized S@rGO nanocomposites for dye photodegradation

Abstract

This study reports the enhanced photocatalytic performance of mechanically synthesized sulfur-intercalated reduced graphene oxide (S@rGO) nanocomposites against methylene blue (MB) and methyl orange (MO) dyes. XRD analysis confirmed sulfur intercalation with increased interlayer spacing and crystallite size ranging from 18 to 44 nm, along with induced tensile strain. Raman and FTIR spectra validated sulfur insertion at oxygen-containing sites in rGO. SEM revealed sheet-like homogeneous morphology, and EDX showed appropriate elemental composition. UV-Vis and PL spectroscopy indicated a tunable band gap (2.04–3.00 eV), crucial for efficient photocatalysis. Kinetic studies followed pseudo-zeroth, first, and second-order models, with rapid dye degradation observed under alkaline conditions. Notably, increased sulfur content enhanced photocatalytic efficiency and reduced long-range crystallinity. Reusability tests confirmed the excellent stability and recyclability of S@rGO nanocomposites, making them promising candidates for optoelectronic and environmental applications.