NANO-PARTICLES ZINC OXIDE FOR WATER CLEANING

Abstract

Organic dye is a major industrial pollutant and needs innovative methods to clear it. Zinc oxide (ZnO) is an attractive material for photocatalytic degradation of organic dyes. In this paper, the photocatalytic activity of ZnO nanoparticles (ZnO NPs) synthesised using chemical bath deposition (CBD) and laser-assisted chemical bath deposition (LACBD) are studied. Field Emission Scanning Electron Microscopy (FESEM) showed that ZnO NPs synthesised using LACBD obtained a more packed structure, resembling nanosheets. This translates to a larger specific exposed area. Energy Dispersive X-ray (EDX) study shows ZnO NPs synthesised using the LACBD method exhibited a Zn:O ratio closer to 1:1, suggesting an adequate concentration of oxygen vacancies, which are crucial for photocatalytic degradation. For the photocatalyst degradation measurement, ZnO NPs are utilized as catalysts in water degradation applications, where 0.01 g of ZnO was added to 50 mL of 20 ppm methylene orange solution. The concentration of methylene orange solution was studied using UV-Vis measurements during photocatalyst degradation. ZnO NPs synthesised using LACBD exhibited the highest photocatalytic degradation performance under UV light, with the highest degradation rate constant, k, of 0.02521 min^-1 and 71% photodegradation efficiency within 30 minutes