Solar degradation of malachite green using nickel-doped TiO₂ nanocatalysts

Abstract

Malachite green (MG) is one of the most used dyes in textile industries. The aim of this research work was to degrade MG, a model dye, using nickel-doped TiO₂ nanocatalysts. Nickel-doped TiO₂ nanocatalysts were fabricated under mild hydrothermal conditions (p = autogenous, T = 100°C, and t = 12 h). Nickel oxide and n-butylamine were used as dopant and surface modifier, respectively. The samples dried were characterized using powder X-ray diffraction, zeta potential, SEM, and electron diffraction X-ray analysis. The batch experiments of MG degradation were performed under UV light and sunlight irradiation. The effect of operational parameters including nanocatalyst dosage, pH, contact time, initial concentration of dye solution, and light source were investigated systematically. It was found that nickel-doped TiO₂ nanocatalysts had better solar degradation efficiency compared with bare TiO₂ under both UV light and sunlight irradiation. The optimum solar degradation efficiency for MG dye solution was achieved at pH 8, nanocatalyst dosage = 1.2 g/l, contact time = 120 min, and initial dye concentration = 250 mg/l.

Keywords:

• Nanocatalysts
• Hydrothermal technique
• Sunlight
• SEM
• Dye

Acknowledgment

The authors are thankful to the Deputy of Research, Kermanshah University of Medical Sciences, Kermanshah, Iran, for financial support.