Construction of Bi2O3/g-C3N4 composite photocatalyst and its enhanced visible light photocatalytic performance and mechanism

To improve the photocatalytic (PC) performance of g-C3N4 nano-material, a novel Z-scheme Bi2O3/g-C3N4 composite photocatalyst was synthesized by heat treatment method. Subsequently, the morphologies, chemical structures, optical and photoelectrochemical (PECH) properties of as-obtained photocatalysts were investigated through X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface areas, UV visible diffuse reflectance spectroscopy (UV vis DRS), transient photocurrent density, Mott-Schottky (M-S) and electrochemical impedance spectroscopy (EIS) measurement. Furthermore, the PC efficiency was evaluated by degradation of amido black 10B dye. All results indicated that as-fabricated Bi2O3/g-C3N4 photocatalytic system displayed superior PC performance under visible light illumination, which was mainly ascribed to the intense visible light absorbance and the migration of photo-generated carriers adopted a Z-scheme mechanism. Moreover, the degradation of amido black 10B for 3 wt.%Bi2O3/g-C3N4 were about 1.41 and 1.42 times than that of pure g-C3N4 and pure Bi2O3, respectively.