(2024) Applied Catalysis B: Environmental_Electron transfer-mediated enhancement of superoxide radical generation in fenton-like process: Key role of oxygen vacancy-regulated local electron density of cobalt sites

Khiem T.C.; Huy N.N.; Kwon E.; Lee J.; Oh W.D.; Duan X.; Wacławek S.; Wang H.; Lisak G.; Ghanbari F.; Lin K.-Y.A.

(Elsevier B.V.) Applied Catalysis B: Environmental ISSN: 9263373 Vol.343 Issue. Article No.123490 DOI: 10.1016/j.apcatb.2023.123490

Designing metal oxides with oxygen vacancy (OV) is a prospective strategy for boosted Fenton-like process. However, what OV is, whether OV enhancement increases the catalytic performance, OV-related H₂O₂ activation, and relationship between OV and ROS or non-radical pathways have not been fully understood. Herein, yolk-shell Co₃O₄ nanospheres with various OV were fabricated to overcome the above contentious problems and establish a relationship between OV, ROS, and electron transfer in sulfadiazine (SDZ) degradation via H₂O₂ activation. The results showed that the delocalized electron-rich Co sites around OV with increasing OV allowed the improved conductivity, thereby leading to stronger adsorption and activation of H₂O₂ to generate more •OH as evidenced by the attenuated adsorption energy and prolonged O-O bond. The subsequent rapid depletion of •OH coupled with the increase in O₂•− over time and the emergence of electron transfer from SDZ explored a pathway enhancing O₂•− generation for SDZ degradation. © 2023 Elsevier B.V.