Pt在CdS表面的控制沉积及其助催化机理（英文）

Controllable deposition of Pt on CdS surface and its co-catalytic mechanism

通过化学还原制备Pt NPs,然后在光分解水反应时通过光诱导沉积于CdS表面.高分辨透射电镜(HRTEM)显示Pt NPs的直径为2～5 nm;X射线光电子能谱分析(XPS)表明,通过化学还原得到的Pt NPs主要为Pt0和Pt2+,而在后续的光诱导沉积过程中,大多数Pt2+进一步被还原成Pt0;CdS光催化剂采用溶剂热法合成,具有纳米棒状结构,直径为40～60 nm,长度为1～2μm.X射线粉末衍射(XRD)分析表明,合成的CdS为六方单晶,纯度较高.紫外-可见漫反射(UV-vis DRS)光谱显示CdS光催化剂的吸收带边为530 nm,荧光(PL)谱图表明负载Pt可以降低CdS荧光峰强度,说明Pt作为光生电子的捕获剂有效分离了CdS的光生电子,提高其光化学转化效率.光解水产氢性能评价实验结果表明,当Pt的负载量为1.25%(质量分数)时,产氢速率最高,为34 mmol·h-1·g-1.

Nano-Pt was prepared by chemical reduction and then photo-induced deposition on the Cd S surface during photodecomposition water reaction. HRTEM showed that the diameter of Pt NPs was 2-5 nm. XPS revealed that Pt NPs obtained by chemical reduction was a complex of Pt0 and Pt2＋,and after the water splitting reaction,most of the Pt2＋was further reduced to Pt0. The Cd S photocatalyst was synthesized by solvothermal method,and had a nanorod structure with its length of 1-2 μm and diameter of 40-60 nm. XRD indicated that the synthesized Cd S is a hexagonal single crystal with high purity. UV-Vis diffuse reflectance spectrum showed that the absorption band edge of Cd S photocatalyst was 530 nm,and PL spectrum indicated that loading Pt decreased the PL peaks intensity,which means Pt functions as the trapper of photo-generated electrons. The experimental results show that when the hydrogen production rate is high up to 34 mmol·h-1·g-1 with the 1.25%（ mass fraction） loading capacity of Pt.