Core-Shell Structural CdS@SnO2 Nanorods with Excellent Visible-Light Photocatalytic Activity for the Selective Oxidation of Benzyl Alcohol to Benzaldehyde
Core-Shell Structural CdS@SnO2 Nanorods with Excellent Visible-Light Photocatalytic Activity for the Selective Oxidation of Benzyl Alcohol to Benzaldehyde
复制标题
具有优异可见光光催化活性的核壳结构CdS@SnO2纳米棒用于苯甲醇选择性氧化为苯甲醛
DOI：
10.1021/acsami.5b04128
复制
发表时间：
2015-07-01
影响因子：
9.5
通讯作者：
Zhang, Jinlong
中科院分区：
文献类型：
--
作者：
Liu, Ya;Zhang, Ping;Zhang, Jinlong
通过溶剂辅助界面反应合成SnO 2纳米粒子，并在超声搅拌下将其锚定在CdS纳米棒表面，制备了核壳结构的CdS@SnO2纳米棒。采用场发射扫描电子显微镜、透射电子显微镜、X射线衍射、X射线光电子能谱和氮气吸附-脱附等手段对样品的形貌、成分和微观结构进行了表征。结果表明，SnO 2纳米粒子可以牢固地锚定在CdS纳米棒表面，且SnO 2壳层的厚度可以通过简单地改变SnO 2量子点的加入量来方便地调节。UV-vis漫反射光谱表明SnO 2壳层也能在一定程度上增强CdS纳米棒的可见光吸收。瞬态光电流和光致发光光谱的结果表明，核壳结构能有效地促进电子空穴对的分离，延长电子寿命。与单一CdS纳米棒相比，核壳结构的CdS@SnO2在可见光下对苯甲醇（BA）选择氧化为苯甲醛（BAD）的光催化活性显著提高，这归因于核壳结构更有效的电子和空穴分离、更大的比表面积和更强的可见光吸收。自由基清除实验证明，在乙腈溶液中，O-中心点（2）-和空穴是BA向BAD转化的主要反应物种，（OH）-O-中心点自由基的缺乏有利于获得高的反应选择性。
Core-shell structural CdS@SnO2 nanorods (NRs) were fabricated by synthesizing SnO2 nanoparticles with a solvent-assisted interfacial reaction and further anchoring them on the surface of CdS NRs under ultrasonic stirring. The morphology, composition, and microstructures of the obtained samples were characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption. It was found that SnO2 nanoparticles can be tightly anchored on the surface of CdS NRs, and the thickness of SnO2 shells can be conveniently adjusted by simply changing the addition amount of SnO2 quantum dots. UV-vis diffuse reflectance spectrum indicated that SnO2 shell layer also can enhance the visible light absorption of CdS NRs to a certain extent. The results of transient photocurrents and photoluminescence spectra revealed that the core-shell structure can effectively promote the separation rate of electron-hole pairs and prolong the lifetime of electrons. Compared with the single CdS NRs, the core-shell structural CdS@SnO2 exhibited a remarkably enhanced photocatalytic activity for selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) under visible light irradiation, attributed to the more efficient separation of electrons and holes, improved surface area, and enhanced visible light absorption of core-shell structure. The radical scavenging experiments proved that in acetonitrile solution, O-center dot(2)- and holes are the main reactive species responsible for BA to BAD transformation, and the lack of (OH)-O-center dot radicals is favorable to obtaining high reaction selectivity.