High Internal Phase Emulsion Template Strategy for the Preparation of UiO-66-NH2 Foam Photocatalysts: A Pseudomonas putida Intimately Coupled UiO-66-NH2 System for Efficient Removal of Antibiotics

Abstract

Intimately coupled photocatalysis and biodegradation (ICPB) is a promising strategy for antibiotic wastewater treatment. Nonetheless, for typical ICPB, the coated photocatalysts not only occupy the carrier’s internal pores for loading microorganisms but also have insufficient adhesion to the carrier, which leads to the loss of gradation performance and cycle stability. Herein, a simple high internal phase emulsion template strategy for constructing a porous UiO-66-NH2 foam (UIO/foam) photocatalyst was designed to couple Pseudomonas putida (P. putida) for the preparation of ICPB. A series of characterizations demonstrated that the UIO/foam with a 3D porous structure not only can work as the excellent photocatalyst with outstanding mass transport ability for degradation of contaminants in the photocatalytic reaction but also serve as the stable biocompatible carrier to in situ cultivate and load P. putida in its internal pores which will further decompose the photocatalytic intermediate products. Profiting from the unique structure and composition, the obtained P. putida/UIO/foam displayed outstanding degradation efficiencies for tetracycline hydrochloride (TCH, 96.9% in 8 h) and ciprofloxacin (CIP, 87.9% in 8 h) and wonderful stabilities after 6 cycles. Also, the liquid chromatography–mass spectrometry test reveals that TCH and CIP are predominantly transformed into non-toxic intermediates in 8 h.