Sustainable NiO@Chitosan Hybrid Photocatalysts for Advanced Organic Pollutant Remediation

Abstract Organic dye contamination of aquatic habitats has become a global issue, necessitating the urgent adoption of radical remediation methods using environmentally benign techniques. This study aims to synthesize and characterize a novel NiO@Chitosan (NiO@CS) composite material that can be used as a photocatalyst for wastewater treatment. The successful preparation of nanocomposites by a coprecipitation method is followed by characterization studies using various techniques, including X‐ray diffraction (XRD), scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FTIR), and UV‐visible spectroscopy, to measure structural and optical properties. The NiO nanoparticles are homogeneously distributed within the chitosan matrix and establish an appreciable crystallographic structure, improving photocatalytic activity. Under UV light irradiation, a degradation efficiency of 86.0% for Crystal Violet (CV) and 86.6% for Rose Bengal (RB) is achieved in 60 min for the NiO@CS nanocomposite. Moreover, the catalyst maintained over 85% of its initial activity for three consecutive cycles, exhibiting excellent reusability and stability. These results indicate the promise of NiO@Chitosan nanocomposites as efficient, recyclable, and eco‐friendly photocatalysts for dye‐based water pollution.