Department of Applied and Environmental Chemistry, University of Szeged, Hungary.
Phys Chem Chem Phys. 2013 Oct 14;15(38):15917-25. doi: 10.1039/c3cp51502h. Epub 2013 Aug 15.
Co nanoparticles were produced and characterized on protonated titanate nanowires. Co deposits were obtained after low-temperature decomposition of Co2(CO)8 on titanate nanostructures. The carbonylation was carried out by vapor-phase adsorption in a fluidized bed reactor and the decarbonylation processes were followed by FT-IR spectroscopy and microbalance combined with temperature programmed reaction mass spectrometry. The band gap of Co-decorated titanate nanostructures determined by UV-VIS diffuse reflectance spectroscopy decreased sharply from 3.14 eV to 2.41 eV with increasing Co content up to 2 wt%. The Co-decorated titanate morphology was characterized by high-resolution transmission electron microscopy (HRTEM) and electron diffraction (ED). The chemical environment of Co deposition was studied by photoelectron spectroscopy (XPS). A certain amount of cobalt underwent an ion exchange process. Higher cobalt loadings led to the formation of nanosized-dispersed particles complexed to oxygen vacancies. The average sizes were found to be mostly between 2 and 6 nm. This size distribution and the measured band gap could be favorable regimes for some important low-temperature thermal- and photo-induced catalytic reactions.
钴纳米粒子在质子化钛酸盐纳米线上进行制备和表征。在钛酸盐纳米结构上，通过低温分解 Co2(CO)8 得到钴沉积物。在流化床反应器中通过气相吸附进行羰基化作用，并用傅里叶变换红外光谱（FT-IR）和微天平结合程序升温反应质谱法（TPR-MS）跟踪脱羰过程。通过紫外-可见漫反射光谱（UV-VIS DRS）确定的 Co 修饰的钛酸盐纳米结构的带隙从 3.14 eV 急剧下降到 2.41 eV，随着 Co 含量增加到 2 wt%。Co 修饰的钛酸盐形态通过高分辨率透射电子显微镜（HRTEM）和电子衍射（ED）进行了表征。通过光电子能谱（XPS）研究了 Co 沉积的化学环境。一定量的钴经历了离子交换过程。更高的钴负载导致形成纳米分散的颗粒与氧空位络合。平均尺寸大多在 2 到 6nm 之间。这种尺寸分布和测量的带隙可能有利于一些重要的低温热诱导和光诱导催化反应。
