本文利用溶胶?凝胶法制备不同Pt掺杂量的纳米TiO2光催化剂（Pt/TiO2），使用X射线衍射仪、透射电镜、紫外可见漫反射光谱和光致发光光谱对其进行表征，并在紫外光与可见光下进行了CO2光催化还原实验。实验结果表明，Pt离子掺杂TiO2纳米催化剂颗粒排列紧密，大小分布均匀，粒径为20 nm左右。Pt/TiO2催化剂在紫外光及可见光下均表现出较高的光催化活性。紫外光下，Pt掺杂量为0.2wt%的催化剂活性最高，其甲烷产率可达66 μmol gcat−1?h−1；可见光下0.3wt% Pt/TiO2活性最优，这是由于铂离子掺杂能有效地将TiO2光响应范围拓展至可见光区，并可抑制光生电子空穴对的复合。
Platinum-ion-doped titania (Pt/TiO2) nanoparticles with varied doping concentration were synthesized by sol-gel method, and characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis) and photoluminescence (PL) spectroscopy. The photocatalytic reduction experiment of CO2 was carried out under UV/visible light irradiation. Results showed that the Pt/TiO2 nanoparticles were arranged closely and uniform-sized, the mean diameter was about 20 nm. CH4 was found to be the primary product for Pt/TiO2 catalysts. The 0.2wt% Pt/TiO2 catalyst showed the best photocatalytic activity with a maximum CH4 production rate of 66 μmol gcat−1?h−1 under UV light irradiation. The activity of 0.3wt%Pt/TiO2 catalyst was highest under visible light irradiation. This is attributed to the doping of Pt ion can effectively extend the spectral response from UV to visible area and slow the recombination of photogenerated electron-hole pairs.
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