Biogenic Nanomaterials as a Catalyst for Photocatalytic Dye Degradation

The demand for dyes is increasing across a variety of industries, including food, rubber, leather, and plastics. Due to their low cost, stability, and performance, people prefer synthetic and semi-synthetic dyes over natural dyes. However, as these dyes are resistant to biological oxidation they are therefore harmful to the environment. More than 1 lakh dyes are available commercially, of which around 10–15% end up in the environment without being treated and it causes adverse effects on the environment. Nowadays these problems are tackled with the help of nanotechnology. The nanoparticles act as a catalyst for the degradation of dyes in the presence of sunlight. In the process of photocatalysis irradiation of light generates electron–hole pair that reacts with water molecules which produces hydroxyl radicals. If the dye reacts with hydroxyl radical it starts decomposing. At the end of the process, H2O and CO2 get released. the biogenic nanoparticle used in these process such as TiO2, ZnO, Fe2O3, Ag NPs, AgO NPs, Au NPs etc. This chapter discusses photocatalytic dye degradation using biogenic nanomaterials.