Highly efficient photocatalytic oxidation of sulfur-containing organic compounds and dyes on TiO2 with dual cocatalysts Pt and RuO2

Photocatalytic oxidation has been demonstrated to be an effective way for removing organic pollutants via a complete mineralization. The removal of sulfur-containing organic compounds in fuel oils and pollutants such as rhodamine B (RhB) and methyl orange (MO) present in the industrial wastewater is highly desired. Here we studied the photocatalytic oxidation of the pollutants on Pt–RuO2/TiO2 photocatalyst. We found that TiO2 co-loaded with noble metal Pt and metal oxide RuO2 shows the considerably synergistic effect between the two cocatalysts on photocatalytic oxidation activity. This effect has been demonstrated for photocatalytic oxidation of thiophene and successfully extended to photocatalytic oxidation of organic dyes. The high activity is achieved by co-loading less than 0.05 wt% Pt and 0.05 wt% RuO2 as cocatalysts on TiO2. ESR measurements give the evidence for that the active oxygen species (OH and O2−) generated by photocatalytic processes are involved in photocatalytic oxidation reactions. The reduction cocatalyst Pt and oxidation cocatalyst RuO2 play significant roles in the photocatalytic oxidation reaction and the co-existing of the dual function cocatalysts is crucial for developing highly active photocatalysts for environmental protection.

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► Highly efficient photocatalytic oxidation of pollutants was achieved on TiO2 co-loaded with Pt and RuO2.
► The co-loaded reduction cocatalyst and oxidation cocatalyst shows considerably synergistic effect.
► The active oxygen species are involved in the photocatalytic oxidation of the pollutants.