Recent Developments in Photocatalytic Techniques of Dye Degradation in Effluents

Abstract

AbstractIn this chapter, we describe how a new trend of materials “nano” and its composites preferential grown as different sizes of small crystallites of structures using varied synthesis routes for photocatalytic dye degradation. Here, we will discuss about the different synthesis methods “traditional and trending” for the purification of water by degradation of dyes using photocatalytic techniques. To support the main outline of this chapter, we have supported various characterizations done to confirm the presence of nanomaterials like XRD for its crystal structure, SEM/TEM for morphology and XPS for elemental analysis; confirming with some functional groups using FTIR and Raman analysis. The modulation of parameters for the purification of water/effluents is pivotal in such work. So, we have compared the new novel techniques and materials trending all over research community as compared to the conventional ones. Certain nanomaterials synthesized are even doped with metals like rare-earth ions and transition metal ions to bring an effective output when illuminated to UV or visible light. Photocatalytic degradation has grown in last 20 years because of the impurities added to water bodies as source from industries and sewage, mainly comprising of waste like chemical dyes. This has paved way for lot of research in the fields of materials science, chemistry, environmental science and energy. Majorly synthetic dyes used in clothes, plastic, leather and other accessories are biggest motif behind this research. Our aim in this chapter is to summarize the whole scenario in compact but covering all relevant information. Usually, the procedure for photocatalytic dye degradation is step-wise process, involving choice of catalyst, concentration of dyes, light illumination and time taken for degradation of dye. Time taken for degradation of dye and choice of materials are inter-related, however efficiency of catalyst for certain dyes is better than other dyes. To make it clearer we will first give a brief introduction on the dyes, photocatalysis process, materials used as catalysts and purification.KeywordsPhotocatalysisDye degradationAdvanced oxidation