Chitosan Based Polymer Membrane Modified with CuO/Graphene Oxide Nanoparticles: Novel Synthesis, Characterization and Enhanced Methyl Orange Removal

This study developed a novel nanocomposite by blending Chitosan and Polyvinyl Alcohol (Ch/PVA) with 1% Copper Oxide nanoparticles (CuO NPs), cross-linked using tetraethyl orthosilicate (TEOS). Three Ch/PVA-based nanocomposites were synthesized using CuO, Graphene Oxide (GO), and a CuO&GO combination. The research aimed to assess the nanocomposites' efficacy in removing methyl orange (MO) dye. The X-ray diffraction analysis revealed that the fabricated CuO NPs had a monoclinic structure with an average particle size of 16.35 nm. The distinctive bands at 3222 cm-1 for the Ch/PVA composite were confirmed by Fourier-transform infrared spectroscopy (FT-IR). Scanning Electron Microscopy (SEM) results confirmed the NPs were well distributed throughout the matrix and Thermal gravimetric analysis (TGA) verified the stability of chitosan till 350 degrees C. The sorption experiments with methyl orange dye were carried out under different pH (2-12), dye concentration (0.025-1.0 mML-1), contact time (0-60 min), and temperature (25-55 degrees C) to establish the adsorbent at the lab-scale. UV-vis results showed the maximum sorption capacity (72 mM/g) achieved within 10 min with 96% dye removal. The adsorption behavior of nanocomposites was attributed to a physicochemical and monolayer adsorption process. Thermodynamic studies at 328 K confirmed that the adsorption process was spontaneous with Delta G degrees value - 4.2 KJmol-1. Also, Delta H degrees and Delta S degrees were found to be 11.3 and 52.2 KJmol-1 for MO adsorption, respectively. This work paves a new route for developing biodegradable, nontoxic, cost-effective, eco-friendly, and highly efficient adsorbents capable of selectively removing and recycling anionic dyes from wastewater.