Pt掺杂TiO2和TNTs光催化剂的特征及光催化产氢性能比较

采用光沉积法掺杂Pt分别制备光催化剂Pt/TNTs和Pt/TiO₂，采用扫描电镜（SEM）、透射电镜（TEM）、X射线衍射（XRD）和紫外可见分光光度计（UV-Vis）对光催化剂进行表征，考察甲醇溶液浓度和Pt掺杂量对光催化产氢效率的影响，并在紫外光（320~400 nm）和可见光（400~700 nm）下比较TiO₂、TNTs、Pt/TiO₂和Pt/TNTs 4种催化剂催化甲醇溶液的产氢效率。结果显示:掺杂Pt可将光催化剂吸收波长红移至可见光区域，由于TNTs具有更大的比表面积，可负载更多的Pt，使电子有效转移至金属上，降低电子电洞对再结合的概率，并增加光催化效果；Pt/TNTs在紫外光和可见光的照射下，光催化效率均高于Pt/TiO₂，在最佳Pt负载量为1%（以质量分数计），甲醇溶液质量分数为20%的条件下，Pt/TNTs在紫外光和可见光下产氢率分别为2331，137.7 μmol/h。对比可知，本研究的可见光催化产氢系统具有很大的发展潜力。

CHARACTERISTICS OF Pt DOPED TiO2 AND TNTs PHOTOCATALYST AND COMPARISON OF THEIR PHOTOCATALYTIC PROPERTIES

The photocatalysts Pt/TNTs and Pt/TiO₂ were prepared by doping Pt by photodeposition method. Characterization of the catalysts was conducted by SEM, TEM, XRD and UV-Vis spectrophotometer. The effect of methanol concentration and Pt doping content on hydrogen production was investigated. And the hydrogen production efficiency of TiO₂, TNTs, Pt/TiO₂ and Pt/TNTs under UV-light (320~400 nm) and visible light (400~700 nm) was compared. The results showed that Pt doping shifted the photocatalysts absorbance into the visible light region. Because of the higher specific surface area of TNTs than TiO₂, more Pt could be loaded, which effectively transfered electronholes to the genus, reduced the probability of recombination of electrons and electrons holes, and increased the photocatalytic effect. Pt/TNTs showed higher hydrogen production efficiency under both UV-light and visible light. Under Pt doping proportion of 1%(by mass), the hydrogen production rate of Pt/TNTs could achieve 2331 μmol/h under UV light and 137.7 μmol/h under visible light with 20% methanol solution(by volume). Compared with other literatures, the visible-light photocatalytic hydrogen production system in this study had resonable development potential.