Visible Light Induced Photocatalytic Degradation of Methyl Orange by Polythiophene/TiO₂ Composite Particles

The adsorption and photocatalytic degradation of methyl orange (MO) aqueous solution under visible light illumination by polythiophene/titanium dioxide (PTh/TiO₂) composite particles were studied. The experimental observations from UV-vis spectrophotometer indicate that MO molecules were degraded in a different degree during the visible light-induced photocatalysis reaction. We propose a new degradation mechanism of MO during the photocatalytic reaction, based on blue shift of UV-vis absorption spectra of MO solution and other researches. The data from total organic carbon analyzer definitely prove that MO can be mineralized to CO₂ and H₂O, and some intermediate products are generated during the photocatalysis degradation of MO.