Introduction

The term photocatalysis is used broadly to describe the activity of photoactive semiconductor materials in a variety of applications. Although the principle of photochemistry is generally understood, the problem lies in the identification of economically feasible applications. Photochemistry is often applied for the degradation of organic pollutants in the environment, and photocatalysis is one such application. Most of the literature dealing with solar photocatalysis describes photocatalysis for wastewater treatment. Semiconductor photocatalysis can suggest one alternative for disposal of waste plastics. Photocatalysts dispersed in polymer matrix and the film of the composite polymer is exposed to sunlight in the presence of air and water. The indoor air polluted with volatile organics can be purified using the principle of photocatalysis. A few studies have been carried out on the removal of volatile matters using gas-phase photocatalysis. Sunlight-assisted photochemical reactions are, therefore, very important with respect to environmental remediation.