A high-performance Bi2O3/Bi2SiO5 p-n heterojunction photocatalyst induced by phase transition of Bi2O3

Abstract In this work, Bi 2 O 3 /Bi 2 SiO 5 p-n heterojunction photocatalyst was successfully fabricated via a facile one-step synthesis using Bi(NO 3 ) 3 and nano-SiO 2 as precursors. With the increasing amount of SiO 2 , α-Bi 2 O 3 gradually transferred into β-Bi 2 O 3, and Bi 2 O 3 /Bi 2 SiO 5 p-n heterojunction was obtained at the same time. The as-prepared samples were systematically characterized by XRD, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS). The Bi 2 O 3 /Bi 2 SiO 5 heterojunction photocatalysts exhibited higher photocatalytic activity than α-Bi 2 O 3 on the degradation of organic pollutants under simulated sunlight irradiation. The enhanced photocatalytic activity could be ascribed to the larger specific surface area, the larger contact angle, the formation of β-Bi 2 O 3 and construction of p-n heterojunction. More importantly, the phase transition mechanism of Bi 2 O 3 in Bi 2 O 3 /Bi 2 SiO 5 heterojunction photocatalyst was proposed, which is significant for the theoretical study and application of photocatalytic materials.