Co~(2+)掺杂的纳米TiO_2薄膜光催化特性及电化学阻抗谱研究

本文采用交流电沉积技术,在多孔氧化铝模板中合成出Co2+掺杂的纳米TiO2薄膜(Co2+/TiO2薄膜)。以次甲基蓝为降解物,研究了纳米Co2+/TiO2薄膜在可见光下的催化性能,考察了阳极偏压对光催化活性的影响。用电化学阻抗谱(EIS)研究了纳米Co2+/TiO2薄膜在次甲基蓝溶液中的电化学行为,给出了相应的等效电路和半导体能带结构参数-空间电荷层宽度。研究表明,适量Co2+掺杂可以提高TiO2薄膜的光催化活性。在Co2+/TiO2膜电极上施加一定阳极偏压,使空间电荷层宽度增加,因此能有效实现光生电子-空穴分离,进一步提高次甲基蓝的光催化降解效率。     

电沉积法制备金属纳米线阵列膜的偏光特性

Metal nanowire array films were prepared by electrodepositing Cu, Ag, Ni, Co and Cu-Ag on porous anodic alumina film. Optical transmittance of both the porous anodic alumina film and metal nanowire array film was measured in the wavelength range of 400---2600 nm under an obliquely incident light. The experimental results show that metal nanowire array films exhibit a prominent polarization function. It was found that optical polarization properties can be improved by choosing suitable kinds of electrodepositing metal, controlling the shape and length of nanowire, and changing the incident angle.     

双自由基CH燃烧反应机理的研究

应用量子理论从头算和密度泛函理论(DFT)对双自由基CH(X2Π)与O2(X3∑g-)的反应机理进行了研究.在B3PW91/6-311G**水平上优化了反应通道上各驻点(反应物、中间体、过渡态和产物)的几何构型,并计算了零点能和过渡态的虚频率.并由B3PW91/6-311G**给出了各物种的总能量.计算表明,反应物中自由基CH与O2反应主要在二重态势能面上进行,CH中的C原子可以插在O2分子中两个氧原子中间形成中间体1(2HCO2),中间体1(2HCO2)可以经过不同的反应通道形成不同的产物P1(1CO2 2H)和P2(1CO 2OH),各反应通道的反应热的计算与实验值吻合较好.     

模板法合成Co纳米线有序阵列的偏光特性

Co nanowire arrays were prepared by anodic alumina oxide template，which formed during DC superposed pulse source anodization process. The structure of porous alumina template and properties of optical polarization of Co nanowire arrays are studied with the help of the scanning electron microscope， X-ray diffraction and infrared spectroscopy. The results showed that Co nanowire arrays have an excellent polarization property in near infrared region in 2700nm. We also found that the properties of optical polarization can also be controlled by adulterating kinds of electrodepositing metal and its alloys， by controlling length of nanowire， and by changing incidence angle.     

纳米金属微粒M-Al2O3介孔复合薄膜的光谱特性

用电化学方法合成了纳米金属微粒M(M=Au,Ag,Cu,Co,Ni,CuAg)-Al₂O₃介孔复合薄膜,并研究了其在近紫外至可见光波范围的光谱特性.研究结果表明,复合薄膜的光吸收峰位置与纳米金属微粒和Al₂O₃介孔薄膜的介电常数有关,且随着膜层中纳米金属微粒复合量的增加,大幅度向红外波段移动;通过共沉积的方法形成的合金微粒复合膜也能使吸收边发生移动.同时还发现Ag-Al₂O₃,Au-Al₂O₃介孔复合薄膜分别在波长为360,500nm处存在等离子体共振吸收峰.