Enhanced photocatalytic activities of facile auto-combustion synthesized ZnO nanoparticles for wastewater treatment: An impact of Ni doping

Abstract

In the current work, we present the facile one-pot synthesis of 0.0, 0.5, 1.0, 2.0 and 3.0 wt% of Ni doped ZnO nanoparticles (Ni:ZnO NPs) through combustion route at 550 °C. Structural and vibrational studies approve the synthesis of monophasic hexagonal Ni:ZnO NPs. The crystallite size was calculated to be in the range of 36–60 nm for pure and doped samples. The composition of all elements in the final product along with their homogeneity, was approved through EDX/FESEM e-mapping analysis. The morphology and phase confirmation of the prepared samples was investigated through FESEM and TEM/HRTEM analyses. TEM/HRTEM study shows that the size of grains is within the range of 100 nm and grown along the c-axis as the lattice spacing is found ∼2.6005 Å. Diffused reflectance study was used to estimate the energy gap for all samples and found to reduce from 3.287 eV for pure to 3.258 eV for 3.0 wt% Ni doping. From an applications point of view, the photocatalytic performance of Ni:ZnO NPs was studied, and with 3.0 wt% of Ni doping in ZnO the degradation of methylene blue (MB) and tetracycline (TCN) pollutants were found to be remarkably improved.