In this paper, the mass-transfer of several basic liquid flow statuses (droplet, ligamentand film), which may appear in the voids of rotating packed beds, is theoretically analyzed.Furthermore, the theoretical results...In this paper, the mass-transfer of several basic liquid flow statuses (droplet, ligamentand film), which may appear in the voids of rotating packed beds, is theoretically analyzed.Furthermore, the theoretical results are compared with the experiments and discussed.展开更多
为开发高效、低成本的电催化氧化系统,在制备Ti_(4)O_(7)多孔膜电极的基础上构建穿流-电催化氧化系统,采用X-射线衍射、压汞法、电子顺磁共振波谱等对Ti_(4)O_(7)多孔膜电极进行表征,分析穿流和非穿流模式下橙黄Ⅱ的电催化降解动力学,...为开发高效、低成本的电催化氧化系统,在制备Ti_(4)O_(7)多孔膜电极的基础上构建穿流-电催化氧化系统,采用X-射线衍射、压汞法、电子顺磁共振波谱等对Ti_(4)O_(7)多孔膜电极进行表征,分析穿流和非穿流模式下橙黄Ⅱ的电催化降解动力学,探究穿流模式下管道压力、电流密度、初始污染物浓度和溶液pH对橙黄Ⅱ电催化降解的影响,验证Ti_(4)O_(7)多孔膜电极的循环稳定性和电催化机制。结果表明:Ti_(4)O_(7)多孔膜电极具有晶体纯度高、比表面积高(10.18 m^(2)/g)、孔径分布集中(0.1~1.0μm)、析氧电位高(2.2 V vs.SHE)等特点;穿流模式可以增强污染物向电极表面的液相传质,进而加速污染物的电催化降解,穿流模式下橙黄Ⅱ的降解率可达91.03%,电流效率为88.77%;穿流模式下,管道压力、电流密度与橙黄Ⅱ的电催化降解速率呈正相关,不同初始质量浓度的橙黄Ⅱ(10~50 mg/L)在穿流模式下均可以被有效降解,最适pH为3~7;Ti_(4)O_(7)多孔膜电极具有良好的循环稳定性,·OH和SO^(-)_(4)·是Ti_(4)O_(7)多孔膜电极电催化过程中最重要的氧化剂。展开更多
Enhancing mass transport to electrodes is desired in almost all types of electrochemical sensing, electrocatalysis, and energy storage or conversion. Here, a method of doing so by means of the magnetic gradient force ...Enhancing mass transport to electrodes is desired in almost all types of electrochemical sensing, electrocatalysis, and energy storage or conversion. Here, a method of doing so by means of the magnetic gradient force generated at magnetic-nanoparticle-modified electrodes is presented. It is shown using Fe3O4-nanoparticle-modified electrodes that the ultrahigh magnetic gradients （〉10^8 T·m^- 1） established at the magnetized Fe3O4 nanoparticles speed up the transport of reactants and products at the electrode surface. Using the Fe（Ⅲ）/ Fe（Ⅱ）-hexacyanoferrate redox couple, it is demonstrated that this mass transport enhancement can conveniently and repeatedly be switched on and off by applying and removing an external magnetic properties of magnetite nanoparticles field, owing to the superparamagnetic Thus, it is shown for the first time that magnetic nanoparticles can be used to control mass transport in electrochemical systems. Importantly, this approach does not require any means of mechanical agitation and is therefore particularly interesting for application in micro- and nanofluidic systems and devices.展开更多
文摘In this paper, the mass-transfer of several basic liquid flow statuses (droplet, ligamentand film), which may appear in the voids of rotating packed beds, is theoretically analyzed.Furthermore, the theoretical results are compared with the experiments and discussed.
文摘为开发高效、低成本的电催化氧化系统,在制备Ti_(4)O_(7)多孔膜电极的基础上构建穿流-电催化氧化系统,采用X-射线衍射、压汞法、电子顺磁共振波谱等对Ti_(4)O_(7)多孔膜电极进行表征,分析穿流和非穿流模式下橙黄Ⅱ的电催化降解动力学,探究穿流模式下管道压力、电流密度、初始污染物浓度和溶液pH对橙黄Ⅱ电催化降解的影响,验证Ti_(4)O_(7)多孔膜电极的循环稳定性和电催化机制。结果表明:Ti_(4)O_(7)多孔膜电极具有晶体纯度高、比表面积高(10.18 m^(2)/g)、孔径分布集中(0.1~1.0μm)、析氧电位高(2.2 V vs.SHE)等特点;穿流模式可以增强污染物向电极表面的液相传质,进而加速污染物的电催化降解,穿流模式下橙黄Ⅱ的降解率可达91.03%,电流效率为88.77%;穿流模式下,管道压力、电流密度与橙黄Ⅱ的电催化降解速率呈正相关,不同初始质量浓度的橙黄Ⅱ(10~50 mg/L)在穿流模式下均可以被有效降解,最适pH为3~7;Ti_(4)O_(7)多孔膜电极具有良好的循环稳定性,·OH和SO^(-)_(4)·是Ti_(4)O_(7)多孔膜电极电催化过程中最重要的氧化剂。
文摘Enhancing mass transport to electrodes is desired in almost all types of electrochemical sensing, electrocatalysis, and energy storage or conversion. Here, a method of doing so by means of the magnetic gradient force generated at magnetic-nanoparticle-modified electrodes is presented. It is shown using Fe3O4-nanoparticle-modified electrodes that the ultrahigh magnetic gradients （〉10^8 T·m^- 1） established at the magnetized Fe3O4 nanoparticles speed up the transport of reactants and products at the electrode surface. Using the Fe（Ⅲ）/ Fe（Ⅱ）-hexacyanoferrate redox couple, it is demonstrated that this mass transport enhancement can conveniently and repeatedly be switched on and off by applying and removing an external magnetic properties of magnetite nanoparticles field, owing to the superparamagnetic Thus, it is shown for the first time that magnetic nanoparticles can be used to control mass transport in electrochemical systems. Importantly, this approach does not require any means of mechanical agitation and is therefore particularly interesting for application in micro- and nanofluidic systems and devices.
