Photocatalytic discoloration of methylene blue by TiO2 P25 under UV light using ISO 10678 standard as a guide

• TiO 2 is the most used semiconductor for photomineralization of organic compounds. • Discoloration of a dye is the most used technique for photocatalytic performance. • ISO 10678:2010 standard was used e for testing the performance of powdered P25 TiO 2 . • Time of exposure, dye concentration and intensity of the UV light were analyzed. • UV intensity was the only factor statistically significant for photocatalysis. In heterogeneous photocatalysis, TiO 2 is the most used semiconductor for mineralization of organic compounds. The most used technique to determine the photocatalytic performance of semiconductors is the discoloration of an organic dye. However, there is no consensus on the procedure for dye discoloration. In this work, the ISO 10678:2010 standard, applied for catalytic surfaces, was used as a guide for testing the performance of the TiO 2 (P25) for the discoloration of methylene blue under UV light. The time of exposure, dye concentration and intensity of the UV light were the parameters of the study. As a result, the UV intensity was the only factor affecting the photocatalysis.