TiO₂ nanotube array is a novel inorganic functional material, its unique chemical and physical properties such as chemical inertness, gas sensitivity, dielectric effect, biocompatibility, better photocatalytic activity and resistance to chemical and light attacks, especially excellent photocatalytic activity, which resulted in many researches and applications in various fields such as storage and utilization of solar energy, environmental clean, catalyst, and photocatalytic degradation of pollutants. TiO₂ nanotube array has been successfully used as photoanodes to transfer solar energy to electric energy, which provides a new way to our energy supply. As a highly efficient catalyst, TiO₂ nanotube array has also transferred macromolecules such as dyes and other persistent pollutants into small molecules like CO₂ and H₂O, which will play an important role in the reduction of pollutants in environment. Meanwhile it can transfer CO₂ to hydrocarbons by reduction reaction which cuts down not only the amounts of CO₂ in atmosphere but also hydrocarbon fuel gases like CH₄ that speed up carbon cycle, and further decrease the greenhouse effects. As a special functional material, it has been proved to be used in monitoring COD value and pollutants in environmental mediums based on its electrochemical properties, and also enriching pollutants at trace or ultratrace levels. Moreover, doping or modification will lead to the migration of the adsorption spectra of the TiO₂ nanotube array to visible region, and enhance the effective use of solar energy. Due to the advantages of low cost and environmental friendliness, more attention has been put on TiO₂ nanotube arrays for the reduction and monitoring of environmental pollutants. This review focused on the photocatalytic degradation of pollutants and applications in environmental analytical chemistry of TiO₂ nanotube arrays in recent years, and provided a reference for developing new techniques for treatment and monitoring of pollutants and widened the potential of TiO₂ nanotube arrays.

Key words: TiO₂ nanotube array, photocatalysis, pollutants, environmental monitoring