Mechanisms of Positive Electric-Field-Enhanced Ti/Anatase TiO₂ (1 0 1) Interfacial Adsorption of Ozone-Inert Pollutants: A Density Functional Theory Study

Abstract

In heterogeneous advanced oxidation processes (AOPs), rapid capture and enhanced adsorption of trace pollutants are prerequisites for effective degradation and mineralization. Here, we propose a novel strategy for using an applied positive electric field to enhance the interfacial adsorption of emerging contaminants (ECs). Density functional theory calculations were used to systematically investigate the effects of the electric field intensity (E) and adsorption site on the adsorption energy (E ads) of ozone-inert ECs when Ti/anatase TiO2 (1 0 1) was used as an interface. Electronic structure and orbital composition analyses were used to further elucidate the mechanism underlying the enhanced interaction between ECs and reaction sites. The results confirmed that the applied positive electric field significantly increased the E ads of ECs. Double water molecule sites (H2O)2 were more favorable for interfacial adsorption than bihydroxyl group (OH)2 sites because the applied positive electric field enhanced the charge enrichment by promoting charge transfer and orbital hybridization between (H2O)2 and ECs, thereby forming new bonds with lower Fermi energy levels and ultimately enhancing EC adsorption. Our results offer new insights into the enhanced adsorption of ECs to promote the decontamination efficiency of heterogeneous AOPs and provide a theoretical basis for conducting related experimental studies.