A review on conductive polymers-modified TiO2 photocatalyst for environmental remediation

Titanium dioxide (TiO2) has garnered significant research interest in recent years for its application in the photocatalytic degradation of organic matter, owing to its affordability, high chemical stability, and environmental compatibility. However, TiO2's wide band gap (3.0-3.2 eV) and low quantum efficiency (< 20 %) hinder its photocatalytic performance. Conductive polymers (CPs), due to their high electrical conductivity and adjustable band gaps, can enhance the absorption of visible light by TiO2 and inhibit the recombination of electron-hole pairs, providing a solution to address these limitations. As a result, CPs are widely employed to modify TiO2. This paper reviews the most commonly used CPs for TiO2 modification, such as polyaniline (PANI), polypyrrole (PPy), and polythiophene (PTh), along with typical modification techniques. Studies the photocatalytic mechanism and the mechanism of enhanced photocatalytic activity of CPs-modified TiO2, highlighting the roles of photosensitization and the synergistic effects of CPs modification in enhancing photocatalytic efficiency. Discusses the application of CPs-modified TiO2 in water treatment, and finally looks ahead to the opportunities and challenges faced by the research on CPs-modified TiO2.