Studies on the titanium dioxide nanoparticles: biosynthesis, applications and remediation

Abstract

Nanoparticles have wide applications in various fields due to their small size. Titanium dioxide nanoparticles are bright with high refractive index (n = 2.4) which makes them suitable for industry dealing with toothpaste, pharmaceuticals, coatings, papers, inks, plastics, food products, cosmetics and textile. Three crystalline phases of titanium dioxide, are anatase (tetragonal), rutile (tetragonal), and brookite (orthorhombic) in which brookite has no commercial value. Due to their self cleaning and antifogging property, they are used in the preparation of cloths, windows, tiles and anti-fogging car mirrors. Titanium dioxide nanoparticles also serve as environment sanitizing agent. Sol–gel route, flame hydrolysis, co-precipitation, impregnation and chemical vapor deposition like techniques are used for the synthesis of TiO2 nanoparticles. Biosynthesis of titanium dioxide nanoparticles has gained wide interest among researchers due to its cost effective, eco-friendly and reproducible approach. The sol–gel route remediation of the titanium dioxide from the environment is an important step and it can be achieved by using physical processes like sedimentation and filtration. The biosynthesis of titanium dioxide nanoparticles can be used in comparison to chemical synthesis. The titanium dioxide nanoparticles have wide applications, viz., reducing toxicity of dyes and pharmaceutical drugs; waste water treatment; reproduction of silkworm; space applications; food industries; etc., and so have immense industrial importance. The applications of nanoparticles synthesized by biological approach will be advantageous for the industries; environment and agriculture.