A novel lateral epitaxial Bi2O3@BiOCl heterostructure for photocatalytic antibiotic degradation in an internal circulation fluidized bed reactor

Designing highly active and stable photocatalysts and promising photocatalytic devices can promote the practical application of photocatalysis, which remains in its early stage. Herein, we design an internal circulation fluidised bed photocatalytic reactor packed with epitaxial Bi2O3@BiOCl (BO@BOC) lateral heterostructures for high-efficiency antibiotic degradation. BO@BOC with defect-free lateral connection forces can initially drive the directional migration of electrons, resulting in efficient charge utilisation, and can subsequently generate abundant hydroxyl and superoxide radicals for superior ciprofloxacin (CIP) degradation (0.0524 min−1). The corresponding pseudo-first-order rate coefficient k of BO@BOC is 0.0524 min−1, which is approximately 57.1 and 10.1 times greater than that of pure BO and BOC, respectively. An 800 mL photocatalytic circulating fluidised bed reactor incorporated with BO@BOC/sponge operated under an LED panel exhibits long-term (10 days) stable CIP degradation (over 90 %) and a satisfactory chemical oxygen demand removal rate in river water, demonstrating its potential as a commercially viable photocatalytic system.