Citrus medica mediated Ag-doped MgO nanocomposites as green adsorbent and its catalytic performance in the rapid treatment of water contaminants

This research article focuses on the synthesis and comprehensive characterization of Ag-MgO nanocomposites (Ag-MgO NCs) using a plant-based material + peels extract as a stabilizing and reducing agent. The primary objective is to investigate the properties of the fabricated nanomaterial through a range of characterization techniques, including UV–visible spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (SEM–EDX), transmission electron microscopy, and thermogravimetric analysis (TGA). Two different peaks were obtained at different wave lengths in the UV–visible spectrum for fabricated nanocomposite. The investigation revealed that the UV–visible spectrum displayed two prominent peaks at 346 nm and 293 nm, corresponding to Ag-NPs and MgO-NPs, respectively. X-ray diffraction patterns indicated a cubic crystalline nature of the fabricated nanomaterials, while the TGA plot demonstrated excellent thermal stability of the Ag-MgO nanocomposite up to 600 °C. SEM analysis unveiled the non-uniform and crystalline characteristics of the nanomaterials. The fabricated nanomaterial proved to be an efficient adsorbent for methylene blue (MB) dye, with a remarkable 100% removal rate achieved at a 4 g/L dose of Ag-MgO NCs. The study further explored the impact of varying doses and exposure times on the adsorption efficiency of the nanomaterial. Additionally, the synthesized Ag-MgO nanocomposite exhibited exceptional catalytic activity, effectively degrading up to 90% of toxic dyes, particularly MB, within a short duration of 8 min. The reaction kinetics followed a pseudo-first-order behavior, with a calculated rate constant of 8.69 × 10^–3 s⁻¹, as determined using a spectrophotometer. In summary, the synthesized Ag-MgO NCs possesses promising potential as an efficient photocatalyst, capable of degrading various hazardous dyes and contributing to water quality improvement.