Degradation of ofloxacin by UVA-LED/TiO2 nanotube arrays photocatalytic fuel cells

Abstract

The degradation of ofloxacin (OFX) at low concentration in aqueous solution by UVA-LED/TiO2 nanotube arrays photocatalytic fuel cells (UVA-LED/TiO2 NTs PFCs) was investigated. TiO2 nanotube arrays (TiO2 NTs) photoanode prepared by anodization-constituted anatase–rutile bicrystalline framework. The results indicated that the degradation efficiency of OFX by UVA-LED/TiO2 NTs PFC was significantly enhanced by 14.3% compared with UVA-LED/TiO2 NTs photocatalysis. The pH affected the degradation efficiency markedly; the highest degradation efficiency (95.0%) and the pseudo-first-order reaction rate constant k value (0.049 min−1) were achieved in neutral condition (pH 7.0). The degradation efficiency increased with the increasing concentration of dissolved oxygen (DO) in the UVA-LED/TiO2 NTs PFC. The main reactive species of OFX degradation are positive holes (h+) and superoxide ion radicals (O 2 ·− ) in a DO sufficient condition. Furthermore, the possible pathways of OFX degradation were proposed.