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The Preparation Of Zirconium And Sulfur Co-doping TiO2 And Sm2Ti2S2O5 And Their Performance Of Photocatalytic Hydrogen Evolution Under Visible Light Irradiation

Posted on:2009-06-07Degree:MasterType:Thesis
Country:ChinaCandidate:Q Z ZhangFull Text:PDF
GTID:2121360278971069Subject:Inorganic Chemistry
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In this thesis,the preparation of zirconium and sulfur co-doping TiO2 and Sm2Ti2S2O5 and their performance of photocatalytic hydrogen evolution under visible light irradiation were researched.The research work is composed of two parts as follows:Part 1:the preparation of zirconium and sulfur co-doping TiO2 photocatalyst and performance of photocatalytic hydrogen evolution under visible light irradiation.The sulfur doping TiO2(S-TiO2) was prepared by the calcinations of mixture of TiO2 and thiourea.Using the S-TiO2 and ZrOCl2 solution,zirconium and sulfur co-doping TiO2 TiO2(Zr-S-TiO2) was prepared by impregnation-calcination method.Pt was deposited on Zr-S-TiO2 by in situ photochemical reduction under visible light irradiation.Using EDTA as an electron donor,the activities of catalysts were evaluated by photocatalytic hydrogen production under visible light(λ≥420nm).The sulfur doping TiO2(S-TiO2) has absorption in visible region and activity for hydrogen evolution under visible light irradiation;zirconium doping enhances further the activity of Zr-S-co-doped TiO2 compared to that of S-TiO2.When calcinated temperature is 500℃,the Pt/S-TiO2 and Pt/Zr-S-TiO2 have the highest activity for evolution of H2 under visible light irradiation. X-ray diffraction,UV-Vis diffuse reflectance spectroscopy,and Fourier transform infrared spectroscopy were used to characterize the catalyst samples.The results showed that the S-Ti-O bond formed in the catalyst could extend the absorption edge to the visible light region.Due to Zr4+ doping,the separation of photoinduced electron-hole pairs can be effectively promoted and thus the evolved H2 activity of Zr-S-co-doped TiO2 is improved compared to that of S-TiO2.Part 2:the preparation of Sm2Ti2S2O5 photocatalyst and performance of photocatalytic hydrogen evolution under visible light irradiation.The precursor was prepared by dropping the mixed solution of TiCl4,SmCl3 and H2O2 into the NaOH solution.Then Sm2Ti2S2O5 was synthesisied by high temperature reaction with the dried precursor and H2S.Pt was deposited on Sm2Ti2S2O5 by in situ photochemical deposition under visible light irradiation.Using HCOOH as an electron donor,the activities of catalysts were evaluated by photocatalytic hydrogen production under visible light(λ≥420nm) irradiation.Experiment results showed that the dried precursor reacted with H2S to produce the Sm2Ti2S2O5 at 850℃for 10 hours.The Sm2Ti2S2O5 has strong absorption in visible region and activity for hydrogen evolution under visible light irradiation.
Keywords/Search Tags:photocatalyst, titanium dioxide, visible ligh, hydrogen evolution, zirconium and sulfur co-doping, Sm2Ti2S2O5, gas solid reaction, coprecipitation
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