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 was proposed with the help of LC–MS analysis. Furthermore, a comparative study on the degradation under solar radiation using Ni-Co/TiO₂ was conducted.

Graphical Abstract