Green synthesis of ZnO nanoparticles from Syzygium Cumini leaves extract with robust photocatalysis applications

Abstract The textile industry consumes excess water for their dyeing process and as a response, they are polluting water bodies. This toxic water is perilous to humans; lessen the aquatic plants' activity too. For the removal of dye toxicity, photocatalytic degradation activity is a practical method of interest. In this work, ZnO NPs were synthesized by biogenic synthesis. ZnO NPs bear the desired physicochemical properties in terms of structural, optical, thermal and photocatalytic properties. In this study, the leaf extract of Syzygium Cumini was used for the synthesis of nanoparticles for the removal of toxicity of MB dye with various properties like eco-friendly, cheap, non-toxic and low time-consuming properties. The aqueous leaf extract was put into the ZnO solution results in the change of colour from yellow to reddish-brown that indicates the reduction of zinc ions in the solution. The synthesized ZnO NPs were characterized by XRD, SEM, FTIR spectrum and UV–Vis spectrophotometer which was used to identify the crystallinity, morphology and functional group responsible for reducing and capping of synthesized ZnO NPs and photocatalytic degradation. The photocatalysis of synthesized ZnO NPs were observed by the degradation of methylene blue (MB, a toxic dye) under sunlight which follows pseudo-first-order kinetics. Synthesized nanoparticles effectively helpful in degrading the MB dye nearly 91.4% at pH 7 and 180 min of exposure time and under sunlight. By using this biogenic method, nanoparticles can be synthesized and used in the removal of other harmful dyes.