Evaluation of photocatalytic and antibacterial properties of SnO2-ZnO nanocomposites developed by Calotropis gigantea leaf extract

In this work, the green synthesis of SnO 2 -ZnO nanocomposites (SnZn NCs) were developed by using Calotropis gigantea (C.G.) leaf extract as a reducing and stabilizing agent. The various SnO 2 - ZnO NCs were prepared by altering the mole ratio of SnO 2 and ZnO such as 80:20, 70:30 and 60:40, respectively. The properties of SnO 2 -ZnO NCs were assessed by XRD, FT-IR, HR-TEM, FE-SEM, EDS, and UV-Vis. DRS analysis. As prepared SnO 2 -ZnO NCs were employed as a photocatalyst for the degradation of Methyl Orange and antibacterial activity. Amongst all NCs, the composition of 70:30 SnZn NCs showed the 99.0 % degradation efficiency against Methyl Orange within 90 min. at 1.5 g/dm 3 catalyst loading. Also, it is found that the individual SnO 2 and ZnO NPs shown 80 and 86 % degradation efficiency of MO respectively. The antibacterial study reveals that SnZn NCs exhibit the better inhibition growth of Staphylococcus aureus and Escherichia coli at the microgram extent compared with SnO 2 and ZnO NPs. The Calotropis gigantea was selected as plant extract because of the presence of bioactive elements which assist in the production and stabilization of SnO 2 - ZnO NCs. • A green ZnO-SnO 2 NCs is developed by using Calotropis gigantea plant leaf extract. • SnO 2 -ZnO NCs (70:30) particles size found to be 12 nm confirmed by HR-TEM. • SnO 2 -ZnO-NCs (70:30) exhibited better photodegradation efficiency of MO(99.95 %) than individual SnO 2 and ZnO NPs. • Antibacterial activity of SnZn (70:30) NCs acted as excellent antibacterial against both gram (+ve) and gram (-ve) bacteria.