Synthesis of a Novel Activated Carbon/ZnO Nanocomposite from the Dead Bark of Indian Jujube for Efficient Removal of Cationic Dye Pollutant

Abstract

In this study, a novel AC/ZnO nanocomposite adsorbent is synthesized from the dead bark of Indian jujube (Ziziphus mauritiana L.). After synthesizing the nanoadsorbent, its structure is elucidated using various spectral techniques. FTIR studies reveal the polar nature of the nanoadsorbent as it consists of carbonyls and alcohol groups. XRD analysis further elaborates that the particle size is 61.72 nm. FESEM and TEM images depict the presence of polar cavities. The pore size was calculated using the BET isotherm and was found to be 3.15nm. After successful synthesis and structure elucidation, the adsorption properties were investigated for their efficiency in adsorbing the toluidine blue (TB) dye from the aqueous phase. To determine the optimal conditions for the adsorption of toluidine blue from water, Batch experiments were conducted by varying the concentrations of both the dye and the nanoadsorbent. The effectiveness of dye removal was confirmed through spectral analysis of the treated dye solutions. The highest removal efficiency recorded was 99.66%, which occurred at a pH of 11.5 with a nanoadsorbent dosage of 50 mg/L. It has been confirmed that the dye is selectively adsorbed by the novel nanoadsorbent, following the Langmuir isotherm, and undergoes pseudo-second-order kinetics, as verified by the kinetic study experiments. Research outcomes highlight the potential of the synthesized nanoadsorbent as an effective dye remover from wastewater. The field implementation of the concerned nanoadsorbent is also economically feasible, as the product is derived from Indian jujube bark, which is abundant in Rajasthan.