金@氧缺陷二氧化钛核壳纳米颗粒的制备及光催化产氢

通过水解TiCl_3在金纳米颗粒外表生长TiO_2,然后在Ar/H2气氛中高温煅烧成功地合成了核壳形貌的Au@H-TiO_2缺陷结构。采用XRD、TEM、XPS、UV-Vis测试方法对产物的物相结构、形貌及光吸收能力做了系统的分析。与不存在缺陷态的TiO_2和Au@A-TiO_2相比,Au@H-TiO_2表现出最高的产氢速率,这可以归因于其电荷分离效率的提高和电荷转移阻抗的降低,瞬态光电流测试以及电化学阻抗数据证实了这一结论。这些性能的改进可能与Au@H-TiO_2中的Ti~(3+)自掺杂和Au修饰有关。     

Self-Organized Micro-Columns and Nano-Spheres Generated by Pulsed Laser Ablation of Ti/A1 Alloy in Water

Dense arrays of micro-columns are formed on the surface of Ti-AI alloy by cumulative nanosecond pulsed laser ablation in water. The fabric-like structure characterized by Ti-A1 nano-spheres absorbed on micro-duster in liquid is most likely responsible for the occurrence of laser micro-etching and localized melting, resulting in continuous deepening of micro-holes and the formation of micro-columns. Laser induced plasma spectroscopy is carried out to reveal the effect of micro-columns on subsequent pulse laser ablation. The intensity of spectral lines from Ti ions by additional laser ablation of the modified spot is higher than that created over a smooth surface. These results suggest that the micro-columns lead to an enhanced absorption of the following laser energy. The proposed results and relevant discussions are of importance for the development of light-trapping coatings on a metal surface.     

金@氧缺陷二氧化钛核壳纳米颗粒的制备及光催化产氢

通过水解TiCl₃在金纳米颗粒外表生长TiO₂,然后在Ar/H₂气氛中高温煅烧成功地合成了核壳形貌的Au@H-TiO₂缺陷结构。采用XRD、TEM、XPS、UV-Vis测试方法对产物的物相结构、形貌及光吸收能力做了系统的分析。与不存在缺陷态的TiO₂和Au@A-TiO₂相比,Au@H-TiO₂表现出最高的产氢速率,这可以归因于其电荷分离效率的提高和电荷转移阻抗的降低,瞬态光电流测试以及电化学阻抗数据证实了这一结论。这些性能的改进可能与Au@H-TiO₂中的Ti³⁺自掺杂和Au修饰有关。     

H原子和SiH2Cl2抽提反应的理论研究

对H+SiH2Cl2反应进行了详细的理论研究,理论证明了抽提氢的通道是唯一可行的反应通道。并在从头算给出的电子结构信息基础上,用变分过渡态理论(CVT)加小曲率隧道效应校正(SCT)等方法对该反应进行了直接的动力学研究,得到该反应的理论速率常数,并详细讨论了各动力学参数沿反应坐标的变化。在较宽的温度范围内,反应速率常数表现出非Arrhenius行为,用三参数公式似合了速-温关系式,为k(T)=(1.32×10^-22)T^3.67exp(-26/T)。理论计算的速率常数与实验数值符合得很好。