Green Synthesis and Characterization of a ZnO-ZrO2 Heterojunction for Environmental and Biological Applications

Abstract

The zinc oxide–zirconium dioxide (ZnO-ZrO2) heterojunction was prepared by a green method using rubber leaves as reducing and capping agents. Various physicochemical techniques were used to study the chemical composition and the structural and optical properties of the synthesized nanocomposite. The nature of the heterojunction was confirmed through X-ray diffraction and the average sizes of ZnO and ZrO2 crystallites were found to be 70 and 24 nm, respectively. The photocatalytic potential of the ZnO-ZrO2 heterojunction was examined against rhodamine 6G (Rh-6G), and 97.30 percent of the dye was degraded due to the synergistic effect of the light and the catalyst. The commercial ZnO nanopowder was used as a reference catalyst and 86.32 percent degradation was noted under the same reaction conditions. The in vitro antioxidant activity was also performed to scavenge the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, where the activity of the ZnO-ZrO2 heterojunction was found to be higher than the ascorbic acid.