Photocatalytic degradation of RB5 dye using commercial TiO2 nanopowder and synthesized TiO2 nanotubes

Abstract

The textile industries use a number of dyes, chemicals to impart desired quality to the fabrics. These industries generate a substantial quantity of effluents which cause environmental problems, if disposed off without proper treatment. At present, due to the increasing resource constraints and the environmental requirements, these textile industries need to adopt a sustainable approach, and wastes generated therefore to be viewed as unutilized resources. Ways and means must be found to recover water and chemicals from these “waste” resources. The conventional treatment processes have various disadvantages and limitations, therefore, cannot be successfully implemented in the textile industry. Advanced oxidation processes seem to be promising as these methods can efficiently degrade the highly toxic and recalcitrant compounds and do not generate any secondary pollutants for disposal. Heterogeneous photocatalysis is the promising method among AOP’s to remove colorants and also to completely degrade into simple substances like CO₂, H₂O and mineral acids. Various catalysts are used of which one of the most is studied TiO₂ due to its unique features such as absolute and relative band positions. The main disadvantage of using TiO₂ is the recombination of electrons and holes which can decrease the efficiency of the process which can be overcome by modifying its structure or incorporating some impurities. This thesis seeks to give a method to study the kinetics of adsorption and of photocatalytic degradation of bare TiO2 as well as TiO2 nanotubes . The dye used was Reactive black 5.