Fe(III)-incorporated UiO-66(Zr)–NH2 frameworks: Microwave-assisted scalable production and their enhanced photo-Fenton degradation catalytic activities

Abstract

In this work, the photocatalytic feasibility of UiO-66(Zr)–NH2 was tuned by combining a scalable producing approach and incorporating Fe3+. Different contents of Fe3+ were effectively incorporated into the UiO-66(Zr)–NH2 frameworks utilizing a microwave-assisted continuous flow tubular reactor within 10 min. It was observed that with increasing the Fe3+ content from 0.5 to 1.0, 2.0 and 3.0 M %, the production rate diminished from ∼ 1.72 to 1.65, 1.55, and 1.46 g/h, respectively. The hybrid Fe@UiO-66-NH2 (Fe@UON) showed enhanced light absorption and charge carrier separation efficiency owing to the newly formed heterostructures, Zr-O-Fe linkages, and –H2N:→ Fe3+ chelating. The optimal Fe@UON catalyst achieved the highest photo-Fenton degradation efficiency of ∼ 96 % towards tetracycline (TC) under energy-saving visible LED light (VLEL) conditions. The photodegradation was predominantly governed by the photo-induced species of ·O2–, h+, and •OH and facilitated by the Fe3+/Fe2+ cycles. At the same time, LC/MS analyses detailedly revealed the reaction pathways for the degradation. After several consecutive tests, the constructed hybrid Fe@UiO-66-NH2 catalysts maintained good catalytic durability, and there was an insignificant Fe leak to the environment. The findings showed that hybrid Fe3+@UiO-66(Zr)–NH2 derived from energy-effective, environmental and scalable methods could be a good material for treating antibiotic-polluted effluents.