【作者】 潘高峰；

【导师】 李越湘；

【作者基本信息】 南昌大学 ， 物理化学， 2007， 硕士

【摘要】 本文研究了TiO₂、ZnO的改性及其可见光光催化制氢性能,研究内容分为两个部分;一、铍、氮共掺杂TiO₂光催化剂的制备及其可见光下光解水制氢性能研究。通过煅烧硫酸钛的氨水水解沉淀物制备氮掺杂TiO₂（N-TiO₂）,再用浸渍法制备了铍、氮共掺杂TiO₂光催化剂（Be-N-TiO₂）。通过可见光光还原沉积法载铂,以EDTA为电子给体,可见光（λ=420nm）光催化制氢为探针反应考察了催化剂的活性。实验表明;氮的掺杂使TiO₂在可见光下具有较强的吸收和活性;铍的掺杂进一步提高了氮掺杂TiO₂在可见光下的活性。当煅烧温度为300℃时,Pt/N-TiO₂和Pt/Be-N-TiO₂可见光光催化制氢活性最高,分别为5.3μmol/3h和11.2μmol/3h。通过DRS、FT-IR、Raman、XRD等手段对掺杂催化剂进行了表征,N掺杂可在TiO₂中形成N-Ti-O键,使其具有可见光吸收能力;掺入Be²⁺可以有效的分离光生电子和空穴,减少了两者的复合,同时能够消除由于氮掺杂引入的氧空位,使共掺杂催化剂相对于单一的N-TiO₂具有较高的可见光制H₂活性。二、伊红-Y敏化ZnO的制备及其可见光制氢性能研究。用浸渍法制备出伊红-Y（Eosin-Y）敏化的M/ZnO（Eosin-Y-M-ZnO,M=Pt,Ru,Cu,Ag）光催化剂,以三乙醇胺为电子给体,通过可见光（λ=420nm）下光解水制氢考察了催化剂的光催化活性,利用IR和UV-Vis漫反射光谱对样品进行了表征。并且研究了染料的浸渍浓度,负载不同的贵金属以及贵金属的负载量对光催化系统制氢活性的影响。实验表明;染料的不同浸渍浓度制备的光催化剂Eosin-Y-Pt-ZnO具有不同的制氢活性,这是由于不同浓度的染料在催化剂的表面达到吸附平衡后,染料的吸附量不同的结果;负载不同贵金属M的光催化剂的制氢活性顺序依次是Ru＞Pt＞Cu＞Ag＞未负载,这是由于染料Eosin-Y在不同贵金属表面的吸附量不同的结果;随着贵金属Pt负载量的增加,光催化剂Eosin-Y-x%-Pt-ZnO的制氢活性提高,这是由于Pt负载量的增加增大了染料Eosin-Y在催化剂表面的吸附量,加速了电子的转移,从而制氢活性得到提高。更多还原

【Abstract】 In this thesis,the modification of TiO₂,ZnO and their performance of photocatalytic hydrogen evolution under visible light irradiation was researched.The research work is composed of two parts;The first part is that preparation of beryllium-nitrogen-codoped TiO₂ and performance of photocatalytic hydrogen evolution under visible light irradiation.The nitrogen doping TiO₂（N-TiO₂）was prepared by the calcinations of hydrolysis product of titanium sulphate with aqueous ammonia.Using the N-TiO₂ and BeSO₄ solution, Be-N-co-doped TiO₂ was prepared by impregnation method.Pt was deposited on Be-N-TiO₂ by photochemical deposition 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 nitrogen doping TiO₂ （N-TiO₂）has strong absorption in visible region and activity for hydrogen evolution under visible light irradiation; Be-N-co-doped TiO₂ further enhances the activity compared to N-TiO₂.When calcinated temperature is 300℃,the Pt/N-TiO₂ and Pt/Be-N-TiO₂ have the highest activity for evolution of H₂ under visible light respectively,namely 5.3μmol/3h and11.2μmol/3h respectively.X-ray diffraction, Raman spectrum,UV-Vis diffuse reflectance spectroscopy,and Fourier transform infrared spectroscopy were used to characterize the catalyst samples.The results showed that the N-Ti-O bond formed in the catalyst could extend the absorption edge to the visible light region.Due to Be²⁺doping,the separation of photoinduced electron-hole pairs can be effectively promoted and the oxygen vacancy produced by nitrogen doping can be removed,and thus the evolved H2 activity is improved compared to N-TiO₂.The second part is that preparation of Eosin-Y sensitized ZnO and performance of photocatalytic hydrogen evolution under visible light irradiation.Using M/ZnO （Eosin-Y-M-ZnO,M=Pt,Ru,Cu,Ag）and Eosin-Y solution,Eosin-Y sensitized M /ZnO was prepared by impregnation method.Using triethanolamine（TEOA）as an electron donor,the activities of Eosin-Y sensitized Pt/ZnO catalyst under visible light （λ=420nm）were evaluated by photocatalytic hydrogen production.Fourier transform infrared spectroscopy,UV-Vis diffuse reflectance spectroscopy were used to characterize the catalyst samples.The effect of concentration of Eosin-Y,loading different noble metal and the amount of noble metal loaded on the activities of the prepared catalysts were investigated.The experimental results are as follows.Because there are different adsorption amounts for dye on catalysts in the various concentration of Eosin-Y when reaching adsorption equilibrium,the catalysts have different activities of hydrogen evolution.When loading the same amount of noble metal M（M=Pt,Ru,Cu,Ag）,the order of activity is Ru＞Pt＞Cu＞Ag＞no metal loaded,because noble metal loaded increases adsorption amount of Eosin-Y,and different noble metal have different adsorption capacity of Eosin-Y.The activities of hydrogen evolution increased with increase of amount of noble metal Pt loading.The reason is that the number of adsorbed Eosin-Y increased with increase of noble metal Pt loading significantly.More metal loading enhances the electron transfer and hydrogen evolution in photocatalytic reaction.更多还原