Synthesis, Characterization, and Application of a Novel Carboxymethyl Guar Gum/Zinc Oxide (CMGG/ZnO) Nano Biocomposite for Methylene Blue Dye Adsorption

Abstract A novel CMGG/ZnO biocomposite was synthesized via the coprecipitation method, combining carboxymethyl guar gum (CMGG) with uniformly dispersed zinc oxide (ZnO) nanoparticles to enhance the physical and chemical properties of the native biopolymer. Structural and functional characterization using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), dynamic light scattering (DLS), ultraviolet–visible spectroscopy (UV–vis), field emission scanning electron microscopy (FESEM), high‐resolution transmission electron microscopy (HRTEM), and proton nuclear magnetic resonance ( 1 H NMR) confirmed successful nanoparticle incorporation, improved crystallinity, and nanoscale particle size ranging from 28 nm to 30 nm. The biocomposite exhibited enhanced thermal stability, mechanical strength, and a significant improvement in dye adsorption efficiency, reaching 64.7% for methylene blue (MB) after 160 min of contact time. These results demonstrate the biocomposite's effective interaction with contaminants and its potential for long‐term application in wastewater treatment. Thus, CMGG/ZnO presents itself as a multifunctional, eco‐friendly material for water remediation. Future work will focus on optimizing synthesis parameters and broadening its applicability in diverse environmental conditions.