In this study, ternary systems of M1M2TiO2 (M1:Co, Cu, Zn) M2 (WO3, MoO3) were prepared and tested for the photocatalytic degradation of sulfamethoxazole. It was found that W-oxo species can be used without significant alteration of the TiO2 activity, while only Cu is a possible candidate for the ternary system either due to its chemical hardness and/or its p-type semiconducting nature.