Ni-Co doped TiO2 catalyst for efficient photocatalytic degradation of Malachite Green under UV and direct sunlight

Abstract

In the present study combustion synthesized TiO2 nanoparticles were wet impregnated with Ni, Co and Ni-Co, respectively. The photocatalytic performance of synthesized catalysts was evaluated against Malachite Green dye. The synthesized materials were characterized for crystallite size, surface morphology, elemental composition, and band-gap using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and ultra-violet diffused reflectance spectroscopy, respectively. The optimum parameters for maximum degradation were found by examining the effects of catalyst loading, initial dye concentration and light intensity. A comparative analysis of Ni-doped, Co-doped, and Ni-Co-doped TiO2 photocatalysts was conducted. The results indicate superior photocatalytic activity of Ni-Co doped TiO2 among the catalysts investigated under UV light. The degradation kinetics was studied and the underlying degradation mechanism is proposed with the help of LC-MS analysis. Furthermore, a comparative study on the degradation under solar radiation using Co-Ni/TiO2 was conducted.