复合光催化剂CdS-Pt/TiO_2制备及可见光光解海水制氢性能

Preparation of CdS-Pt/TiO_2 Composite and the Properties for Splitting Sea Water into Hydrogen under Visible Light Irradiation

水热法制备了单斜CdS与Pt/TiO2复合的光催化剂.通过X射线衍射、紫外-可见漫反射光谱、荧光光谱、扫描电子显微镜和BET方法对催化剂进行了表征.以可见光光解纯水和海水制氢为探针反应,考察了CdS-Pt/TiO2光催化剂的活性.结果表明:海水中无机盐的存在有利于电子给体捕获光生空穴,提高了电子和空穴的分离效果;海水中单斜CdS可转化为立方和六方混合晶相.最佳条件下,催化剂光解海水制氢活性比纯水提高了33%,而且有较高的稳定性.

Composite photocatalyst of monoclinic CdS coupled with Pt/TiO2 was prepared by a hydrothermal met- hod. The photocatalyst was characterized by X-ray diffraction （XRD）, UV-Vis diffusive reflectance spectroscopy （DRS）, scanning electron microscopy （SEM） and BET. The photoactivity was evaluated by hydrogen evolution from pure water and seawater solution under （λ≥420 nm） visible light irradiation. It has been found that the inor- ganic salts in sea water are beneficial to the electron donors trapping photogenerated holes. The separation of photo- generated electrons and holes is promoted. CdS can be transformed into cubic and hexagonal mixed phases in sea water. Under optimal conditions, the activity of hydrogen generation in seawater was 33% higher than that in pure water. CdS-Pt/TiO2 composite photocatalyst has a higher stability in the seawater.