This work examined the use of pure TiO2, pure heteropolyacid (HPA) H5PW10V2O40 and TiO2 + H5PW10V2O40 catalysts in the photocatalytic decomposition of dimethyl sulfide (DMS) in the gas phase. DMS was irradiated with visible light from an LED (lambda > 400 nm), black light UV-A (lambda < 400 nm) and visible fluorescent lamp 'daylight' (variable emission in the UV-A and visible range). DMS decomposition reached almost 100% for the system containing the TiO2 + H5PW10V2O40 mixed catalyst with exposure to visible daylight. This system maintained stable catalytic activity up to 500 min. These results strongly suggest that a positive synergistic effect occurred between TiO2 and HPA when visible daylight was used. (C) 2014 Elsevier B.V. All rights reserved.