Ta3N5 nanoparticles/TiO2 hollow sphere (0D/3D) heterojunction: facile synthesis and enhanced photocatalytic activities of levofloxacin degradation and H2 evolution

Abstract

Active removal of recalcitrant antibiotic contaminants for wastewater purification and hydrogen evolution from water splitting using hollow-structured photocatalysts has attracted considerable interest in the field of environmental governance and energy conversion. Herein, 0D Ta₃N₅ nanoparticles anchored on 3D TiO₂ hollow nanosphere composites (0D/3D Ta/Ti) were designed and fabricated via a feasible surface self-assembly process for the first time. Various techniques were employed to characterize the structure and optical properties of the as-prepared samples. The photocatalytic activities of Ta₃N₅/TiO₂ hybrids were systematically evaluated via both photodegradation of levofloxacin (LEV) and water splitting for hydrogen evolution under solar light irradiation. The degradation results showed that the x-Ta/Ti composites exhibit remarkably better performances for LEV degradation than pristine TiO₂. The 3 wt% Ta₃N₅ nanoparticle-loaded hollow TiO₂ composite material exhibited optimal photocatalytic activity (92.79%), and its degradation rate constant was 3.04 times that of TiO₂. Simultaneously, the 3-Ta/Ti composite also possessed high ability to degrade other antibiotics such as ciprofloxacin (CIP) and tetracycline hydrochloride (TCH) and colored organic dyes such as Rhodamine B (RhB). Besides, x-Ta/Ti composites exhibited higher photocatalytic hydrogen evolution activities compared with TiO₂ hollow spheres. The efficient charge transfer and separation between the close heterogeneous interfaces, broadened spectral response range and improved specific surface area were mainly responsible for the superior photocatalytic performance of the x-Ta/Ti nanocomposite. Our study provides an effective strategy for the design of hollow structure composite photocatalysts with excellent photocatalytic performances not only for pollutant removal, but also for efficient solar-to-fuel conversion.