Preparation of Bi3Fe0.5Nb1.5O9/g-C3N4 heterojunction photocatalysts and applications in the photocatalytic degradation of 2,4-dichlorophenol in environment

Abstract

In this study, ferroelectric oxide Bi₃Fe_0.5Nb_1.5O₉ (BFNO) was selected to self-assemble BFNO and g-C₃N₄ to form a composite heterojunction photocatalyst BFNO/CN. BFNO was used to form a spontaneous polarized electric field, which can accelerate the separation and migration of driving photogenerated electron–hole pairs at the heterojunction interface of the two components. The morphology and structure of the prepared composites were characterized and analyzed using various instruments. Further, the optical and electrical properties of the materials were investigated. The photocatalytic performance of the material was evaluated by the photocatalytic degradation of 2,4-dichlorophenol (2,4-DCP) under visible light irradiation. The degradation efficiency of BFNO/CN is much higher than that of a single component. In 120 min, BFNO/g-C₃N₄ (66 wt%) showed the best degradation performance (83.7%), which was about 7.2 times and 4.0 times those of g-C₃N₄ (11.7%) and BFNO (21.1%), respectively. It showed good reusability and stability even after five cycles and is a good material for the phenol wastewater treatment.