Synthesis of Crosslinked Chitosan-Tartaric Acid/Nano Copper Oxide Polymer Nanocomposite for Safranin T Dye Adsorption: Characterization and Adsorption Optimization

This study aims to prepare a chitosan-based nanocomposite of crosslinked chitosan-tartaric acid/copper oxide nanoparticles (CTS-TA/CuO) for safranin T (SFT) dye adsorption. The CTS-TA/CuO nanocomposite was extensively characterized using Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), and X-ray diffraction (XRD). The BET analysis revealed a mean pore diameter of 12.14 nm and surface area of 7.49 m²/g. The adsorption process was optimized using the Box–Behnken design (BBD), considering key parameters such as CTS-TA/CuO dosage (0.02–0.08 g), solution pH (4–10), and contact time (10–50 min). Kinetic modeling demonstrated that the adsorption followed the pseudo-first-order model, while equilibrium data best fit the Freundlich isotherm model. The maximum adsorption capacity of the CTS-TA/CuO nanocomposite for SFT was computed to be 210.48 mg/g. The adsorption mechanism was attributed to multiple interactions, including electrostatic attractions, n-π interactions, and hydrogen bonding. Overall, the findings of this study highlight the promising capability of the CTS-TA/CuO nanocomposite as an efficient and reliable adsorbent for the removal of SFT dye from polluted water, signifying its prospective utilization in wastewater treatment techniques.