Structural, Adsorptive, and Antibacterial Properties of a Novel Silver (Diethyldithiocarbamate)-Decorated Reduced Graphene Oxide Nanocomposite for Sustainable Wastewater Treatment

Eco-friendly silver nanoparticle systems are highly effective due to their large surface area and strong adsorption capacity. In this study, a novel silver (diethyldithiocarbamate)-decorated reduced graphene oxide nanocomposite (Ag(DDTC)@rGO) was synthesized via a simple green method, yielding a stable and monodispersed material. SEM and HRTEM analyses revealed uniform anchoring of the Ag(DDTC) complex on rGO, producing a coherent nanocomposite with strong physicochemical coupling. The Ag(DDTC)@rGO nanocomposite exhibited a high Brunauer–Emmett–Teller (BET) surface area (289 m2 g−1) with an average pore diameter of 45 nm, confirming the mesoporous nature of the composite. FTIR spectra showed characteristic bands of rGO and DDTC ligands, with new peaks at 620–640 cm−1 confirming the successful anchoring of silver–diethyldithiocarbamate species onto rGO via Ag–S and Ag–O bond formation. Raman spectroscopy further confirmed the multilayered rGO structure after Ag(DDTC) incorporation. X-ray diffraction (XRD) identified a broad hybrid amorphous–crystalline pattern, favorable for catalytic and sensing functions. The superior malachite green adsorption capacity of Ag(DDTC)@rGO was attributed to synergistic electrostatic, π–π stacking, hydrogen bonding, and silver-mediated interactions. Furthermore, antibacterial assays demonstrated significant inhibition of P. aeruginosa ATCC 9027 and S. enterica ATCC 14028, further enhanced by mild heat activation (40–50 °C) that significantly improved the surface activation of silver nanoparticles. The multifunctional Ag(DDTC)@rGO nanocomposite exhibits strong adsorption and antibacterial properties, highlighting its potential for sustainable wastewater treatment and environmental remediation applications.