Improved photoelectrocatalytic degradation of methylene blue by Ti3C2Tx/Bi12TiO20 composite anodes

In order to effectively reduce the high recombination rate of photogenerated carriers when Bi₁₂TiO₂₀ (BTO) was excited by visible light, Ti₃C₂T_x/BTO/fluorine-doped tin oxide photoanodes were conveniently prepared with the aid of mechanical coating by gentle ultrasonic mixing. Systematic characterization and the degradation of methylene blue in a photoelectrochemical cell were performed. The results showed that the Ti₃C₂T_x/BTO composite exhibited a strong light absorption ability and the effective separation of photogenerated carriers. The optimal anode (6 wt% Ti₃C₂T_x/BTO) degraded 85.4% of methylene blue within 120 min at an applied electric field of 1 V, with a reaction rate that was 3.5 times that of BTO. It was proved that Ti₃C₂T_x, as a useful co-catalyst, creates an internal electric field at the contact interface with BTO and an external electric field, which are responsible for the enhanced photoelectrocatalytic degradation capacity of the composite anode materials.