Garcinia xanthochymus mediated green synthesis of ZnO nanoparticles: Photoluminescence, photocatalytic and antioxidant activity studies

Green synthesis of multifunctional zinc oxide nanoparticles (ZnO Nps) was achieved employing water extract of Garcinia xanthochymus by solution combustion synthesis. The structure and morphology were determined by XRD, UV-visible and scanning electron microscopy studies. The ZnO Nps were evaluated for photoluminescence (PL), photocatalytic and antioxidant properties. The water extract was found to comprise significantly high amounts of polyphenols and flavonoids. Powder XRD studies indicate the formation of pure wurtzite structure with absorption maximum of 370 nm corresponding to band gap energy of 3.33 eV. SEM studies reveal the formation of spongy cave like structures. The PL spectra exhibited 4 emission edges at 397, 436, 556 and 651 nm upon excitation at 325 nm because of oxygen deficiencies and zinc interstitials. Nps exhibit remarkable photodegradation of methylene blue (MB) in presence of UV and sun light. They exhibit antioxidant activity by inhibiting the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Therefore, the study reveals an efficient, ecofriendly and simple method for the green synthesis of multifunctional ZnO Nps.