Experimental Study of the Photocatalytic Behaviour of Zinc Oxide Nanostructure for Cationic Dye (Malachite Green)

In the present study, ZnO nanostructures formed by co-precipitation have been investigated for their photocatalytic behaviour against the cationic dye (Malachite Green). X-ray diffraction (XRD) technique has been used to identify the structure, crystallite size, and phase of the as-synthesized material. Surface morphology and elemental compositional analysis of the ZnO have been carried out using a scanning electron microscope (SEM) attached with an energy-dispersive spectrometer (EDS). The SEM study has revealed the formation of round-shaped pebble-like particles having sizes between 50 to 150 nm and found to be uniformly distributed. XRD analysis has shown well-resolved peaks of ZnO, indicating a polycrystalline nature with a hexagonal structure. The crystallite size has been calculated and found to be about 18 nm. Absorbance spectra have been recorded using a UV-Vis spectrometer and the optical band gap energy has been found to be 3.29 eV. Band-gap excitonic emission displays emission peaks in the photoluminescence spectrum at 390 nm. The results have shown the degradation of Malachite Green dye using ZnO nanoparticles in 3 hours, with 95% efficiency. The decomposition of the dye with ZnO nanoparticles can be utilized in industrial wastewater treatment for the benefit of mankind and the aquatic ecosystem, including their habitats.