Fang Siman, Li Songsong, Ge Lei, Han Changcun, Qiu Ping, Gao Yangqin
State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum Beijing, No. 18 Fuxue Rd., Beijing 102249, People's Republic of China.
Dalton Trans. 2017 Aug 15;46(32):10578-10585. doi: 10.1039/c6dt04682g.
Cobalt oxide decorated octahedral ceria hollow structures (CoO/CeO) with various contents of CoO nanoparticles were prepared via a simple chemical impregnation method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse-reflectance spectroscopy (DRS), surface photovoltage spectroscopy (SPV) and transient photovoltage spectroscopy (TPV). The photocatalytic oxygen evolution via water oxidation was investigated for the as-prepared CoO/CeO nanocage composites. The photocatalytic results indicate that the CoO/CeO nanocage composite with 1 mol% CoO shows the highest photocatalytic activity. The excellent photocatalytic activity can be attributed to the improved visible-light absorption of CoO/CeO composites and the efficient separation of excited electron-hole pairs between CoO and CeO, which can effectively enhance the lifetime of charge carriers in the CoO-modified samples and then improve the oxygen evolution activity. Cobalt oxide is expected to be an excellent water oxidation co-catalyst for semiconductor photocatalysts.
通过简单的化学浸渍法制备了具有不同含量氧化钴纳米颗粒的氧化钴修饰八面体氧化铈空心结构（CoO/CeO）。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、高分辨率透射电子显微镜（HRTEM）、X射线光电子能谱（XPS）、紫外-可见漫反射光谱（DRS）、表面光电压光谱（SPV）和瞬态光电压光谱（TPV）对所得样品进行了表征。对制备的CoO/CeO纳米笼复合材料通过水氧化进行光催化析氧研究。光催化结果表明，含1 mol% CoO的CoO/CeO纳米笼复合材料具有最高的光催化活性。优异的光催化活性可归因于CoO/CeO复合材料可见光吸收的改善以及CoO和CeO之间激发电子-空穴对的有效分离，这可以有效提高CoO修饰样品中载流子的寿命，进而提高析氧活性。氧化钴有望成为半导体光催化剂优异的水氧化助催化剂。
