Preparation of three-dimensionally ordered macroporous composite Bi2O3/TiO2 and its photocatalytic degradation of crystal violet under multiple modes

Abstract

Polystyrene latex (PS) spheres and EO20PO70O20 (P123) were used as dual template agents, with TiO2 as the matrix, to prepare a three-dimensionally ordered macroporous (3DOM) composite Bi2O3/TiO2, using a sol-gel method and post-processing calcination. The phase structures, chemical composition, morphology, and surface physicochemical properties were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), ultraviolet-visible diffuse reflectance (UV-Vis DRS) and X-ray photoelectron spectroscopies (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), scanning electron microscopy (SEM), and N2 adsorption-desorption measurements. The results show that the composite is well crystallized and has a highly ordered porous structure with mesoporous walls; it is a 3DOM material. The light absorption of 3DOM-Bi2O3/TiO2 is red-shifted by about 60 nm to the visible region compared with TiO2. In the photocatalytic degradation of crystal violet using various methods, namely ultraviolet, visible-light, and microwave-assisted irradiation, the activity of 3DOM-Bi2O3/TiO2 is significantly higher than those of P25, Bi2O3, and Bi2O3/TiO2. The 3DOM-Bi2O3/TiO2 composite also shows good photocatalytic activity in the degradations of various dyes under ultraviolet irradiation. The 3DOM-Bi2O3/TiO2 activity is well retained after three cycles. © Editorial office of Acta Physico-Chimica Sinica.