ZnO and Ni-doped ZnO photocatalysts: Synthesis, characterization and improved visible light driven photocatalytic degradation of methylene blue

The nickel modified zinc oxide (ZnO) photocatalysts with nominal composition of Zn1-xNixO (x = 0.0–0.5) were synthesized by wet chemical approach. Optical studies were performed using Fourier transformed infrared (FTIR), electronic spectroscopy and X-ray diffraction (XRD) methods. Scanning electron microscopy (SEM) complimented with Energy Dispersive X-ray (EDX) was used to study the morphology and chemical composition of prepared photocatalysts. A significant hypsochromic shift has been observed with respect to un-doped ZnO nanocatalyst due to quantum confinement effect. Subsequently, the band gap has been tuned to the region of lower wavelength. X-ray results reveal that ZnO nanocatalyst are in hexagonal crystalline form. In addition, the effect of nickel impurity on photocatalytic activity of ZnO nanocatalysts in degradation of methylene blue (MB) was also investigated. Degradation results showed that the MB was degraded more effectively by Ni-doped ZnO photocatalysts due to large band gap under visible light irradiation.