Thermal and photochemical degradation of dimethylsulfoxide on TiO2

► Thermal decomposition of dimethylsulfoxide on TiO2 occurs at a temperature >100 °C. ► With dissociation of the C-S and C-H bonds, CH3O, HCOO and S are formed. ► O2 has negligible effect on the thermal reaction, but transforming the S to SO4. ► DMSO(a) photodegradation in a vacuum generates CH3O, HCOO and CH3S. ► The presence of O2 further oxidizes the CH3S into CH3SO3.