SYNTHESIS AND CHARACTERIZATION OF COBALT OXYHYDROXIDE NANOMATERIAL FOR WASTEWATER REMEDIATION

Abstract

The unregulated discharge of synthetic dyes into water bodies has emerged as a critical environmental concern, endangering aquatic ecosystems and posing serious health risks to humans. The present study reports the synthesis of novel cobalt oxyhydroxide (CoOOH) nanomaterial, via facile and sustainable two-step route, for efficient adsorptive removal of cationic dye i.e. Brilliant Green (BG) from wastewater. The synthesized CoOOH was comprehensively characterized using powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (FE-SEM/EDX), Brunauer–Emmett–Teller (BET) surface area analysis, and dynamic light scattering (DLS). From the BET analysis, it was observed that CoOOH nanomaterial exhibited a mesoporous structure with a specific surface area of 36.160 m² g-1 and a substantial negative zeta potential of –34.4 mV, promoting strong electrostatic interactions with BG dye molecules. Batch adsorption experiments demonstrated an outstanding removal efficiency of 99.40% for BG dye within just 30 minutes, under optimized conditions. The adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. The equilibrium data fitted best to multilayer, non- homogeneous Freundlich isotherm model, exhibiting a maximum uptake capacity of 111.11 mg g-1. This study not only underscores the potential of CoOOH as an adsorbent but also presents a scalable, low-cost, and environmentally benign solution for dye- contaminated wastewater remediation. The findings offer a promising platform for the advancement of next-generation adsorbent nanomaterials for sustainable environmental remediation strategies.