Point-defect-induced electronic polarization to enhance H* generation for removal of bisphenol A

Abstract

Intrinsic point defects in metal core-shell materials can regulate electron redistribution, thereby reducing catalytic energy barriers and enhancing their ORR activity. However, their specific contributions to electron transfer and mass transport pathways remain unclear. In this study, defect-rich hollow O_Co@Co₃O₄ nanoparticles were successfully synthesized using ZIF-67(Co) as a sacrificial template through controlled annealing and internal electric field substitution reactions. High-resolution electron microscopy analysis and density functional theory (DFT) calculations co-revealed the growth mechanism of Co and O vacancies, as well as antisite defects. The formation of oxygen vacancies significantly lowered the energy barrier for Co vacancy formation, playing a crucial bridging role in the development of antisite defects. The electric field polarization induced by Co-O atomic displacement resulted in asymmetric charge distribution, optimizing the adsorption of active hydrogen (H*) and oxygen atoms and facilitating the generation and release of reactive oxygen species (ROS). Electrocatalytic experiments demonstrated that under the combined action of singlet oxygen (¹O₂) and H*, bisphenol A (BPA) can be efficiently degraded. This study successfully bridges the knowledge gap between atomic defects and advanced electrocatalysis, providing a new perspective and insight for the in-depth analysis of the structure-performance relationship of electrocatalyst materials in the future.