Low temperature synthesized ZnO/Al ₂ O ₃ nano-composites for photocatalytic and antibacterial applications

Abstract

Abstract Urbanization promoted the leaching of abiotic and biotic pollutants in freshwater ecosystem and created the demand for sustainable technologies to ensure a supply of fresh water in the future. As a type of sustainable technology, nanomaterials have been enlisted as a potential candidate. In the present study, a series of ZnO/Al 2 O 3 nano-composites (ZANC) were synthesized with a cost-effective method, followed by their application as a photocatalyst and as an antibacterial agent. ZANC were characterized for crystallinity, particle size, surface morphology, chemical state and band gap. ZnO with 10% Al 2 O 3 content, calcined at 400 °C (ZA-2A) was found to be the optimal photocatalyst for the photo-degradation of dye, cibacron red and the pesticide, triclopyr (TC). Additionally ZANC showed improved antibacterial activity against both gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative ( Escherichia. coli and Pseudomonas aeruginosa ) microbes. The enhanced antibacterial and photo-degradation properties of the ZANC could be seen as a synergistic effect of amorphous Al 2 O 3 and ZnO. Based on the outcome, ZANC has shown its potential for a sustainable solution towards the removal of organic dyes, pesticides and microbes in contaminated water.