Nickel doped zinc oxide with improved photocatalytic activity for Malachite Green Dye degradation and parameters affecting the degradation

Zn1 − xNixO (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) was synthesized successfully using chemical co-precipitation method. The structural, morphological and optical properties of the synthesized samples were investigated using XRD (X-ray diffraction), SEM (scanning electron microscope), EDX (energy-dispersive X-ray), TEM (transmission electron microscope), FTIR (Fourier transform infrared) and UV–Vis spectroscopy. The photocatalytic activities of the synthesized samples toward the degradation of Malachite Green (MG) dye under UV light irradiation were studied. Zn0.94Ni0.06O was observed to be the better photocatalyst among the studied samples which degrades 77% of the dye under 4 h of irradiation. The effect of operational parameters such as catalyst dosage, initial dye concentration and pH on the degradation percentage was investigated. An optimum condition was obtained for a catalyst load of 0.10 g/L into 15 ppm dye solution at pH 9 which degrades 76% of the dye under 1hour of UV irradiation. Reusability test of the photocatalyst was also performed to check the stability for long-term application of the samples.