Biogenic Synthesis of Zinc Oxide/Chitosan Nanocomposite Using Callistemon Citrinus (bottle Brush) for Photocatalytic Degradation of Methylene Blue

AbstractDischarges from various industries have polluted water bodies, resulting in adverse health problems both to the aquatic biota and humans. The biological approach to treat these wastewaters is considered ecologically friendly, sustainable, and reliable. The present study investigates the efficiency of green fabricated ZnO/chitosan nanocomposite (NC) for methylene blue (MB) dye photodegradation in an aqueous solution under ultraviolet irradiations. The fabricated NC is characterized using different techniques such as X‐ray diffractometer (XRD), Field Emission Scanning Electron Microscopy (FE‐SEM), UV–Vis spectroscopy, Energy Dispersive X‐rays (EDX), and Fourier Transform‐Infrared spectroscopy (FTIR). ZnO/chitosan NC is used for the photodegradation of MB under different conditions. The results reveal that the ZnO‐Chitosan NC efficiently photodegraded 99.2% of MB dye under the experimental condition (Temp = 25 °C, photocatalyst dose = 0.2 g L‐1, contact time of irradiation 120 min at pH 8). The photodegradation process has been found to follow pseudo first‐order kinetic model. Photocatalyst after desorption can be used seven times effectively. The photodegradation model has also been proposed.