Photocatalytic activity of pectin capped bio-synthesized NiO nanoparticles for in situ synthesis of 2-phenylbenzimidazoles

Due to its simplicity, affordability, convenience, and lack of hazardous chemicals, the production of metal nanoparticles made from herbal extracts is one of the environmentally benign processes. Green tea aqueous extract is used as a reducing/stabilizing agent under ultrasonic conditions to effectively formulate nickel oxide nanoparticles stabilized by pectin (NiO NPs/pectin) using a number of environmentally friendly techniques nowadays. X-ray diffractometer (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and a field emission scanning electron microscope (FE-SEM) were used to characterize the generated NiO NPs/pectin. According to the TEM image, the NiO NPs were evenly distributed and had spherical, average diameters between 30 and 50 nm. By testing its photocatalytic performance for the synthesis of 2-phenylbenzimidazoles using the benzyl alcohol reaction with o-phenylenediamine, the novelty of surface-engineered nanocomposite was validated. In situ photocatalytic oxidation of benzyl alcohols to their related benzaldehydes in ambient air without the need of an oxidizing reagent is the key focus of the current study. Excellent yield were obtained in short reaction time (90-96%). Eight successful recycling cycles of the produced catalyst were achieved without a discernible drop in catalytic potential that justifies the material as a promising and novel photocatalyst.