Bio-extract assisted in-situ green synthesis of Ag-RGO nanocomposite film for enhanced naproxen removal

The present study reports in-situ green synthesis of Ag-RGO nanocomposite film using turnip leaves-extract as a reducing as well as a capping agent and its application as a highly efficient naproxen adsorbent from a contaminated aqueous solution. The nanocomposite was characterized employing XRD, Raman and FT-IR spectroscopy, FETEM and FESEM microscopy, EDS spectroscopy. The pseudo-second-order and Elovich kinetic model furnished the best correlation of the experimental data, specifying the adsorption as the rate-limiting step for naproxen (NPX) removal by Ag-RGO composite film. The Freundlich and Dubinin-Radushkevich (D-R) isotherms represented the experimental adsorption data satisfactorily, suggesting a multilayered chemical adsorption process on the heterogeneous adsorbent surfaces. The process parameters were optimized to get the maximum adsorption capacity, which was obtained as 229.25 mg g−1 (92.62%). The parametric effects of pHs and NPX concentrations were tested within a range of 2.50–8.50 and 25–100 mg dm−3, respectively, for the contact time of 0.33–3 min at a constant temperature (298 K) and adsorbent dose (20.2 mg). The feasibility of the regeneration of the materials after adsorption is based on the experimental results. The experimentally optimized process parameters were validated using response surface methodology (RSM).