Sustainable Fabrication of Metal-doped rGO Nanocomposites for Photocatalytic Antibiotic Degradation in Aqueous Systems

Antibiotic contamination in aquatic environments has been widely reported due to the extensive discharge from pharmaceutical industries, as well as human and veterinary medical practices. Even at trace concentrations, these compounds have been found to exert serious mutagenic and carcinogenic effects, raising significant environmental and public health concerns. β-lactam antibiotics, including ampicillin and cephalexin, represent a major class of antibacterial agents characterized by the presence of a β-lactam ring. However, no universally accepted treatment strategy has been established for their effective removal from water bodies. Conventional physical and chemical remediation methods were reported to be either time-consuming or economically inefficient. In response, numerous studies have explored the green synthesis of silver-based graphene nanocomposites using plant-derived biomass, such as Azadirachta indica, as cost-effective and eco-friendly alternatives for antibiotic degradation. These nanocomposites demonstrated promising photocatalytic activity under various environmental conditions, including variations in pH, contact time, and initial drug concentration. Characterization techniques such as UV-Vis spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), particle size analysis, and zeta potential measurements were employed to evaluate their structural and surface properties. The efficiency of photocatalytic degradation was commonly assessed through UV-Vis spectrophotometry, while statistical optimization using Response Surface Methodology (RSM) provided insights into the interaction of operational parameters. This review summarizes recent advances in the development, characterization, and application of green-synthesized Ag/rGO nanocomposites for the photocatalytic removal of β-lactam antibiotics from aqueous systems.