Silica Nanosphere‐Coated Cellulose Nanocomposite for Copper and Zinc Adsorption From Wastewater: Isotherm Analysis

ABSTRACT This study investigated the potential of a silica nanosphere–coated cellulose (SNCC) nanocomposite as an innovative adsorbent with a high surface area to efficiently remove copper (Cu 2+ ) and zinc (Zn 2+ ) from aqueous solutions. The synthesis of the SNCC nanocomposite involves a combination of decolorized cellulose and silica extracted from rice husk using the sol‐gel technique, resulting in a cost‐effective synthesis procedure. Nanocomposite was characterized using FTIR analysis, field‐emission scanning electron microscopy, and energy‐dispersive x‐ray dot‐mapping analysis to detect chemical functional groups on it, investigate the morphology of the adsorbent particles, and study the uniform distribution of silica nanospheres on the SNCC nanocomposite, respectively. Adsorption experiments of Cu 2+ and Zn 2+ were performed in which various parameters, such as the effect of adsorbent dose, pH, temperature, and contact time. Moreover, the adsorption data were fitted to several adsorption isotherms to more precisely evaluate the governing adsorption mechanism. The experimental results revealed the high efficiency of the nanocomposite in removing Cu 2+ and Zn 2+ ions under various batch conditions, with maximum adsorption capacities of 32.370 and 52.870 mg/g for Cu 2+ and Zn 2+ , respectively. Hence, the promising results demonstrated a cost‐effective, environmentally friendly adsorbent that effectively removed heavy metal ions from wastewater.