| Semiconductor photocatalysis technology has attracted the attention of many researchers due to its advantages of simplicity,high efficiency and environmental friendliness.This technology has strong application potential in the environmental protection.In this work,Bi2WO6 with different morphologies were synthesized by the hydrothermal method,and the In2O3/Bi2WO6 and y-AgI/Bi2WO6 composites were prepared through the modification method of which combined with another semiconductor.The properties of the photocatalyst were analyzed by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),transmission electron microscope(TEM),UV-vis diffuse reflectance spectrum(UV-vis DRS),photocurrent(PT)and so on.Besides,the photocatalytic degradation of several common antibiotics or dyes was carried out under visible light irradiation to evaluate the photocatalytic performance of the as-prepared composites.Finally,combining the results of experiments and characterization analysis,the possible photocatalytic degradation mechanisms in the two systems were discussed.The details are as follows:1.In this experiment,Bi2WO6 nanosheets were synthesized by a simple hydrothermal method using Bi(NO3)3·5H2O and Na2WO4·2H2O as raw materials,with the assistance of cetyltrimethylammonium bromide(CTAB).Then,the In2O3 nanoparticles were loaded on the surface of the Bi2WO6 nanosheets through calcination method,and a series of binary composites were obtained by optimizing the loading of In2O3.The morphological characterization results showed that the agglomeration of single-component was effectively reduced due to the construction of heterojunction.The photocatalytic activity was evaluated by degrading tetracycline(TC)and oxytetracycline(OTC)under visible light.The results of the study showed that the In2O3/Bi2WO6 composites had higher catalytic performance.Finally,the main active species in the photodegradation process was analyzed through the capture experiments.And based on the characterization results,a possible transfer mechanism of the photogenerated carriers was proposed.2.The Bi2WO6 with three-dimensional spherical structure was prepared via a hydrothermal method,in which bismuth nitrate and sodium tungstate were used as bismuth source and tungsten source,respectively.Then AgNO3 and KI were added,andγ-AgI/Bi2WO6 heterojunction photocatalysts with different mass ratios were prepared by a simple precipitation method.The rhodamine B(RhB),hydrochloride(TC)and ciprofloxacin(CIP)were selected as target pollutants for photodegradation reaction under visible light.The results showed that all the γ-AgI/Bi2WO6 composite materials exhibited enhanced photocatalytic activity compared with single components.Its excellent photocatalytic performance might be due to the formation of a heterojunction between spherical Bi2WO6 and nano-particle γ-AgI,which could improve the visible light response capability and the separation efficiency of photogenerated carriers.Finally,a possible Z-scheme mechanism was also proposed combining the capture experimental and ESR tests. |
