Interfacial interaction-induced shift of d-band center promotes photocatalytic antibiotics mineralization

The position and offset of the center of the d band affected by the interface electric field improve the catalytic activity, and the formation of chemical bonds at the interface provides an atomic fast path for electron transfer. In this work, oxygen-containing vacancies in WO3-x/C3N4+x heterojunction were prepared through the hydrothermal method. UPS and DFT results show that the giant work function difference between WO3-x and C3N4+x leads to the redistribution of orbital charge at the heterojunction interface, thus creating an interfacial electric field and N-W bond. The upward shift of the center of the W 5d electron orbit triggered the adsorption capacity of WO3-x/C3N4+x heterojunction for molecular oxygen, which improves photocatalytic degradation efficiency. The degradation of antibiotics in real lake water and the toxicity study by degraded wastewater have demonstrated the thoroughness of mineralization, while the continuous light Fenton system has been shown the stability of the catalyst. This study provides a new insight into the association between the interface electric field and the d-band center, opening a facile avenue for the design of catalysts towards antibiotics photocatalytic mineralization.