One-pot synthesis of Bi2O3/Bi2O4 p-n heterojunction for highly efficient photocatalytic removal of organic pollutants under visible light irradiation

Abstract

Construction of p-n heterojunction is an effective strategy to obstacle the rapid recombination of photo-generated carriers for single photocatalyst. Herein, visible-light-active Bi2O3/Bi2O4 p-n junction was prepared by a one-pot hydrothermal method, using Bi(NO3)3·5H2O, KCl, and NaBiO3·2H2O as precursors. The in-situ formed BiOCl reacts with NaBiO3·2H2O during the hydrothermal process, producing the target product of Bi2O3/Bi2O4 p-n heterojunction. As expected, the obtained Bi2O3/Bi2O4 heterojunction photocatalysts exhibited higher photocatalytic activity than Bi2O4 for the degradation of MO (methyl orange) and phenol under visible-light irradiation. The superior photocatalytic performance of Bi2O3/Bi2O4 hybrid is mainly attributed to the improved separation efficiency of e--h+ pair induced by the internal electric field of p-n junction. The present work may provide a rational and facile strategy to construct a highly efficient Bi2O4-based p-n heterojunction photocatalyst toward pollutant removal.