Novel oxygen vacancy–enriched SnO2-x–Sb@SnO2 homojunction integrated with two crystallization levels for efficient degradation of organic pollutants

• An interfacial internal electric field through SnO 2-x -Sb@SnO 2 crystallinity differences. • The homojunction SnO 2-x -Sb@SnO 2 catalyst integrated with two crystallization levels was set up. • The mechanism of oxygen vacancies on conductivity and water adsorption were investigated via DFT. • The 3D electrode demonstrates excellent oxidation performance in degradation of multiple organic pollutants . Electrochemical (EC) oxidation is a promising technology for the degradation of emerging and persistent organic pollutants in water remediation. It is urgent priority to develop an electrode with high efficiency, long cycle life and high safety characteristics. In comparison to traditional titanium (Ti), three-dimensional porous substrates, such as Ti foam, is more beneficial for the rapid mass transfer. Herein, an engineering vacancies (O vs ) homojunction SnO 2-x -Sb@SnO 2 catalyst integrated with two crystallization levels (high-crystallinity and low-crystallinity) is developed to enhance the degradation activity of organic pollutants. The Ar-assisted Ce doping-induced O vs enhance the electrochemical performance and durability of the composite electrode by boosting interfacial electron transfer. Specifically, the Ti foam/SnO 2-x -Sb@SnO 2 with high concentration of O VS demonstrated an exceptionally rapid degradation rate of cephalexin (CFX) at 0.05490 min −1 , facilitated by both radical attack mechanisms and direct electron-transfer (DET) processes. The novel anode demonstrated exceptional stability, with a predicted service life of 2.3 years. The theoretical calculations indicate the multiple contact interfaces present in the homojunction SnO 2-x -Sb@SnO 2 catalyst strengthen the interfacial internal electric field (IEF). This enhanced IEF significantly aids in facilitating charge separation and transfer at the interface, which is vital for improving electrochemical performance. This engineered interfacial design opens up new opportunities for the development of highly efficient and stable electrodes.