Low-cost nano-TiO2 composites for remediation of textile dyes: Appraisal on the effect of solar and ultraviolet irradiations

The study evaluates the azo dye degradation potential of nano-TiO2; its composites with low-cost substrates in the form of powder and encapsulated bead for two widely used azo dyes, methyl orange (MO) and congo red (CR) under solar and ultraviolet (UV) irradiation. Degradation potential varied according to the dye concentration, chemistry of dye, light source, and the formulation of the photocatalyst. Both the dyes were completely decolorized at 100 mg/L concentration and to some extent at 1,000 mg/L concentration. The activated charcoal-titanium dioxide (AC-TiO2) nanocomposite in the presence of solar radiations proved to be an economic and efficient substrate for degradation of the test dyes exhibiting combined action of adsorption and photocatalytic phenomena.