Biogenic approach for synthesis of ZnO/NiO nanocomposites as a highly efficient photocatalyst and evaluation of their biological properties

Abstract

Mixed metal oxide-based nanocomposites (NCs) have remained broadly used for photocatalysis-facilitated elimination of harmful substances from the aquatic ecosystem. Nowadays, searching for an improved photocatalyst looks plentiful; metal oxide-based materials have begun to emerge from studies. In the present work, the use of ZnO/NiO NCs as photocatalytic treatment of wastewater utilizing oxides of metals as photocatalysts has become a subject of major concern. The way of coupling with other semiconductors for improved photodegradation in the presence of UV-visible light. NCs were mainly characterized by XRD, FT-IR, UV-DRS, morphological studies such as SEM and TEM, and elemental composition by EDAX, which all affirmed the effective synthesis of NCs. For instance, ZnO/NiO NCs having a bandgap of about 3.11 eV achieved outstanding degradation activity toward 100% photodegradation of methylene blue (MB) within a short period of time. Further, prepared ZnO/NiO NCs have excellent antibacterial activity against both Gram-negative and Gram-positive bacteria. This behavior is primarily caused by the accumulation of ZnO/NiO NCs on the bacteria’s surface, which results in cytotoxic bacteria and a relatively increased ZnO, resulting in cell death. Also, ZnO/NiO NCs exhibit essential, harmless effects on human red blood cells and their intervention with the action of clotting on both PPP and PRP in human erythrocytes. As an outcome, the studies have shown that Phyllanthus Niruri (L) mediated synthesis by combustion methods performs well as a good capping agent to synthesize ZnO/NiO NCs with important multi-disciplinary applications.

Graphical abstract