Synthesis And Photocatalytic Activity Of Mesoporous Photocatalyst

In recent years, people are facing the increasingly serious environmental pollution and energy crisis problem. Therefore, the use of high efficiency, low energy consumption, clean and no secondary pollution photocatalytic technology to remove pollutants is becoming a hot spot of research. As a kind of photocatalyst, Ti O2 has been widely studied. However, the 3.2 e V broadband gap of Ti O2 semiconductor limits its application in visible light catalysis. Meanwhile, the high electronic-hole recombination of Ti O2 lead to its low photocatalytic efficiency. In order to improve the photocatalytic efficiency, it is very important to study the Ti O2 modification. In this paper, the mesoporous Ti O2 were modified by hydrothermal treatment, ion doping and semiconductor compound. Specific research contents and conclusions are as follows:(1) The mesoporous Ti O2 photocatalyst was prepared by sol-gel method. And then,five kinds of different concentration of acid and alkali solution were used to treat the mesoporous Ti O2 by hydrothermal process. The samples were characterizated by SEM,XRD and nitrogen adsorption-desorption. And the photocatalytic activitythe samples were evaluated by degradation of RB and MB under 500 W xenon lamp. The results showed that hydrothermal treatment can change the surface morphology of Ti O2, after hydrothermal treatment, the Ti O2 surface become rough, surface area increased and pore diameter reduced. Lower concentration of acid and alkali solution hydrothermal treatment can help the growth of Ti O2 grain, and higher concentration of alkali hydrothermal treatment can hinder the growth of Ti O2 grain size. Compared with the untreated mesoporous Ti O2, the Ti O2 after acid solution hydrothermal treatment and 450 ℃ calcined, have better removal effect to RB. The Ti O2 after five kinds of solution hydrothermal treatment without calcined all have better adsorption ability of MB. The Ti O2 after 0.1 mol/L HCl solution hydrothermal treatment and 450 ℃ calcined have better photocatalytic effect to MB.(2) The mesoporous Fe2O3/Ti O2 photocatalysts were synthesized via a sol-gel process.The samples were characterized by SEM, XRD, nitrogen adsorption-desorption,fluorescence and UV-vis DRS. The photocatalytic activity of the Fe2O3/Ti O2 photocatalysts were evaluated by degradation of BPA, RB and MB under 500 W xenon lamp. The results indicated that the Ti O2 was mainly anatase type. With the increase of Fe, the surface area ofthe obtained photocatalysts increased, the absorption edge appeared red shift,electronic-hole recombination time reduced and its quantum efficiency increased. The Fe2O3/Ti O2 photocatalysts with Fe/Ti of 3% have better photocatalytic activity.(3) The mesoporous Cdx Zn1-x S/Ti O2 photocatalysts were synthesized via a sol-gel process. The samples were characterized by SEM, XRD and UV-vis DRS. The photocatalytic activity of the Cdx Zn1-x S/Ti O2 photocatalysts were evaluated by degradation of BPA, RB and MB under 500 W xenon lamp. The results indicated that Cdx Zn1-x S was successfully added to the Ti O2, the Ti O2 was mainly anatase type. After the incorporation of Cdx Zn1-x S, new diffraction peaks appeared and the visible light response of Ti O2 were extended. The Zn S/Ti O2 have better degradation effect to BPA, the Cd0.8Zn0.2S/Ti O2 have better degradation effect to RB and MB.