In-situ construction of MOF-5 derivatives photoanode for the rapid degradation of antibiotics: Electrochemical deposition and self-growth strategy

Abstract

Traditional powder-coated photoanodes suffer from poor interfacial-tightness and high complex interfacial mass transfer resistance. In addition, the treatment rate of photoanodes on antibiotics is limited due to the electrode active area and the mutual restriction between the electrode and the height of treated liquid. Ar-ZnO/Ti3+-TiO2-NTs photoanode in this study solved the above problems. Ti3+-TiO2 nanotubes (Ti3+-TiO2-NTs) after electrochemical reduction were used as the conductive substrate. MOF-5 was grown in situ on the substrate by pulsed deposition and microwave hydrothermal self-assembly, which provided both high active sites and effective photosensitivity. Finally, Ar-ZnO/Ti3+-TiO2-NTs photoanode was constructed after reduction atmosphere sculpture. The stable structure of TiO2 hollow nanotubes and the three-dimensional network structure of MOF-5 were beneficial to improve the high-pressure resistance of the structure in the process of photoanode application. Meanwhile, the reduced self-doping of Ti3+ enhanced the substrate conductivity, the pulsed deposition of Zn decreased ion leaching, and the microwave accelerated the self-assembly process of MOF-5. The Ar-ZnO/Ti3+-TiO2-NTs photoanode performed excellent degradability for multiple antibiotics (greater than 90%, 60 min) with the photoelectrocatalytic synergy factor of 21.16, and the performance was maintained after three months. This work enriched photoelectrode development, and provide novel ideas for MOFs to participate in antibiotic removal.