Preparation Of Bismuth Oxide And Study On The Photocatalytic Properties

In recent years,bismuth semiconductor photocatalyst attracted people's attention research.Bismuth halide BIOX(X = Cl,Br,I)as a new type of photocatalysts,had the special layered structure and proper band gap.It showed a good photocatalytic activity under the light irradiation.Organics could be effectively degraded by it.In this page,we synthesized three kinds of photocatalyst,bismuth oxyiodide,bismuth oxybromide and bismuth oxychloride by hydrothermal synthesis method.In the synthetic process,absolute alcohol was used as a solvent.The influence factors of synthesizing bismuth oxide were studied,including the order and the speed that ionized water and kalium jodalium joined into the solution,the reaction time of the solution at different temperatures,and then the synthesis conditions of preparing bismuth oxyiodide were determined.What's more,an extended experiment was carried out.The GF-BiOI composite material that bismuth oxyiodide adhered to the surface of the modified glass fiber.Three kinds of photocatalyst and GF-BiOI composite were analyzed the by The X-ray diffraction(XRD),scanning electron microscope(SEM),ultraviolet visible diffuse reflectance(UV-vis),infrared spectroscopy analysis(FT-IR)and thermo-gravimetric analysis.Bismuth oxyiodide,bismuth oxybromide and bismuth oxychloride showed a good crystallinity through XRD analysis.The characteristic peaks of Bi-0 bonds were observed their infrared spectra characterized through the FT-IR method.These two methods showed that the photocatalysts can be successfully synthesized.The bismuth oxyiodide particles were three dimensional spherical.Bismuth oxybromide and bismuth oxychloride particles were the shape of clouds,while that the particle size of the fomer is smaller than that of the later by observing the SEM picture.GF-BiOI composite could improve the dispersion of Bismuth oxyiodide powder.UV-vis analysis showed that bismuth oxyiodide photocatalyst can almost absorb visible light that is less than 700 nm.However,the others only can absorb ultraviolet.Based on the thermogravimetric analysis,the decomposition peak of GF-BiOI composites were lower than that of bismuth oxyiodide powder.This change reduced the decomposition temperature and stability of bismuth oxyiodide powder.The photocatalytic activity of these substances was explained through the degradation of methyl orange solution.Under UV irradiation,the degradation rate of methyl orange with bismuth oxychloride powder was about 99.7%,while that of the solution with bismuth oxybromide was 98.2%.Under the irradiation of xenon,the degradation rate of methyl orange was 92%.Three kinds of photocatalyst showed low photocatalytic activity when the solution irradiated by the end optical fiber.The catalytic activity was higher when the side light fiber was used.Its catalytic activity was the highest by the Xe lamp irradiation.The degradation rate of methyl orange was 97.0%with GF-BiOI composite material.Finally,the availability and stability of the photocatalysts were illustrated.