The Influence of the Preparing Method of a Ag/Ga2O3 Catalyst on its Activity for Photocatalytic Reduction of CO2 with Water
The Influence of the Preparing Method of a Ag/Ga2O3 Catalyst on its Activity for Photocatalytic Reduction of CO2 with Water
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DOI：
10.1380/ejssnt.2014.263
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发表时间：
2014-01-01
影响因子：
0.7
通讯作者：
Yoshida, Hisao
中科院分区：
文献类型：
--
作者：
Yamamoto, Naoto;Yoshida, Tomoko;Yoshida, Hisao
采用溶液等离子体法（SPM）和浸渍法（imp）制备了载银氧化镓（Ag/Ga 2 O3）光催化剂，考察了Ag纳米粒子的化学状态和粒径对其光催化活性的影响。在所有的Ag/Ga 2 O3光催化剂上，CO2与水的光催化还原反应都能生成CO，但CO的生成速率在光催化反应过程中有所降低。UV-VIS漫反射光谱、XANES光谱和TEM图像的测量结果表明：Ag/Ga 2 O3（imp）样品中存在Ag氧化物纳米颗粒，其粒径分布较宽，在5 ~ 10 nm之间。在紫外光的照射下，它们变成了大量的金属纳米粒子，并且变成了尺寸约为100 μ m的大颗粒。20 nm的光催化反应。另一方面，所制备的Ag/Ga 2 O3（SPM）样品中的Ag纳米颗粒是尺寸小于10 nm的金属。在紫外光照射下，样品的粒径基本不变，但在光催化反应过程中，样品的粒径变大，与Ag/Ga 2 O3（imp）样品的情况相似。这种尺寸为5-10 nm的小金属Ag纳米颗粒适合于CO生产。然而，他们聚集在反应过程中为5小时，降低光催化活性。
We have prepared silver-loaded gallium oxide (Ag/Ga2O3) photocatalysts by the solution plasma method (SPM) and impregnation method (imp), and investigate the effects of the chemical states and the size of the Ag nanoparticles on their photocatalytic activities. The photocatalytic reduction of CO2 with water proceeds over all the Ag/Ga2O3 photocatalysts to produce CO, however the CO production rates decrease during photocatalytic reaction. Measurements of UV-VIS diffuse reflectance spectra, XANES spectra and TEM images reveal the followings: the Ag oxide nanoparticles in the as-prepared Ag/Ga2O3 (imp) samples exist and their size distribution is wide from 5 to 10 nm. They become a lot of metallic nanoparticles by UV light-irradiation, and become larger particles with the size of ca. 20 nm during the photocatalytic reaction. On the other hand, the Ag nanoparticles in the as-prepared Ag/Ga2O3 (SPM) samples are metallic with the size of less than 10 nm. The size does not change under UV light irradiation, while become larger particles during the photocatalytic reaction as similar to the case of the Ag/Ga2O3 (imp) samples. Such small metallic Ag nanoparticles with the size of 5-10 nm are suitable for CO production. However, they aggregate during the reaction for 5 h to degrade the photocatalytic activity.