Abstract

Colourful dyes are primarily used in the textiles, toys, food, inks, paper and plastics. These dyes are water soluble and contaminate the water. The dyes are not bio-degradable and sustain in the water for long time create diseases like bladder tumour and chromosomal damage. Hence dyes are the major cause of pollution and must be removed from domestic and drinking water. The photocatalysts are energy-less technology for dye degradation and expected to solve dean water problems. Most of the photocatalysts are metal oxides and absorbed in the ultra violet region. But, sun light mostly consists of visible light, hence to use the sunlight effectively the absorption spectrum of the photocatalysts must be tuned to the visible region. Herein, we proposed visible light absorbed new TiO2/NiO nanocomposite for methyl orange dye degradation. The integration of NiO modified the TiO2 nanocomposite UV absorption spectrum into visible light region. The photocatalyst was prepared using mechano-thermal method and characterised using PXRD, TGA, FT-IR, HR-TEM, EDS, UV, PL and DRS methods. The photocatalytic property was explored using the degradation of methyl orange and compared the activity with different time intervals and wide range of pH. Within 60 min of irradiation. 98% of degradation was observed. Similarly, at all pH range more than 50% of degradation was observed, but the best performance (98%) was observed at pH - 7 (neural). Thus, the TiO2/NiO nanocomposite catalyst was effective in neutral, acidic and basic polluted water treatment. The synthesized TiO2/NiO nanocomposite is tuneable to visible light and degrade the methyl orange dye in all pH range. (C) 2020 Elsevier B.V. All rights reserved.