Ultra-high oxygen evolution potential of CuO5-Zn1 active sites on SnO2(1 1 0) surface and its origin: DFT theoretical study

SnO2 is an anode material with the potential to form a high oxygen evolution potential for organic wastewater treatment. Previous experiments found that CuZn, co-doped with SnO2 surfaces were suspected to form Cu-O-Zn sites with high catalytic activity. By utilising DFT calculations combined with previous experimental results, it was found that CuO5-Zn1 active sites were formed on the (1 1 0) surface of CuZn co-doped SnO2 with an oxygen evolution potential of 2.80 V (vs CHE). The electronic density of states, charge density distribution, Bader charge and charge density difference analysis indicated that the formation of ultra-high oxygen evolution potential was caused by the enhanced covalency of Cu-O-Zn. The indirect covalent enhancement between transition metal atoms found on the SnO2 surface means that atomically regulated and controlled catalytic activity can be achieved on the SnO2 surface.