Introduction of Cluster-to-Metal Charge Transfer in Uio-66-Nh2 for Enhancing Photocatalytic Degradation of Bisphenol a in the Existence of Peroxymonosulfate

Abstract

Nowadays photocatalysis assisted advanced oxidation processes exhibited a great application prospects in pollution control. Herein, for the first time, a series of transition metal modified UiO-66-NH2 (namely Fe-UiO-66-NH2, Co-UiO-66-NH2 and Ni-UiO-66-NH2) were synthesized via a simple method. After that, these functional materials were employed as photocatalyst to activate PMS for degrading BPA under visible light irradiation. Significantly, prepared Fe-UiO-66-NH2 exhibited the highest photocatalytic activity among these samples. More importantly, proposed Fe-UiO-66-NH2/PMS/light oxidation system showed excellent degradation ability for various organic pollutants, including BPA, TC, OFX, IBP as well as SMX. Owing to the occurrence of d-d transitions after the coordination of transition metal ions, UiO-66-NH2 displayed the enhanced utilization efficiency of visible light. Furthermore, introduced Fe ion as a mediator could boost the charge transfer by the cluster-to-metal way, thereby effectively inhibiting the recombination of photogenerated electrons and holes. In addition, embedding cluster-to-metal charge transfer in UiO-66-NH2 modified the band structure, and both SO4−• and •OH were major active species in the photocatalytic reaction system. Developed Fe-UiO-66-NH2/PMS/light oxidation system with good stability also presented great antibacterial performance. To sum up, current work could provide some novel inspirations for designing the high-efficiency photocatalyst.

Keywords: photocatalysis, Metal-organic frameworks, Peroxymonosulfate activation, Photocatalytic mechanism, Pollutant degradation