Photodiscoloration of textile reactive dyes on Ni/TiO2 prepared by the impregnation method: Effect of calcination temperature

Abstract

In this work, we report the preparation of Ni/TiO2 (2 and 5wt%) catalysts by the impregnation method and calcinations temperature (250, 300 and 400°C) for the discoloration of dyes reactive orange-122, reactive blue-19 and reactive yellow-145 under artificial and solar light. The characterization techniques used were: N2 adsorption measurements (BET method), scanning electron microscopy (SEM) with energy dispersive X-ray (EDS), temperature programmed reduction (TPR), X-ray diffraction (XRD), thermogravimetric analyzer (TGA) and photoacoustic spectroscopy (PAS). The experimental results under artificial light indicate that the photocatalyst 5% Ni/TiO2 calcined at 400°C discolored dye reactive yellow-145 aqueous solutions 91.78% in 8h, in contrast to 2% Ni/TiO2 calcined at 400°C with 41.82% to dye reactive blue-19 and 5% Ni/TiO2 calcined at 250°C to dye reactive orange-122 with 48.20%. The photocatalyst 5% Ni/TiO2 calcined at 400°C under solar irradiation in 60min, is more efficient in the discolored dye reactive orange-122 aqueous solutions 92.16%.