Particulate-based Imaging Amperometry for Rapid Measurement of Current Dist ribution

技术描述：本项目的核心假设是胶体粒子可以作为局部电化学电流密度的探针。这项创新的本质是在电极极化过程中利用胶体粒子发出的散射光。在实验中，胶体颗粒将分散在电化学电池中使用的测试电极上。以大于临界角的入射角引入的激光辐射将在靠近电极的地方产生倏逝辐射。这些粒子将这些转瞬即逝的波散射成可见光。粒子动态响应局部电流密度，这意味着粒子将局部电流密度转换为具有可测量强度的光。理论将光的强度转化为电流密度的测定。当使用粒子群时，该方法在电极上创建电流密度图像。在薄膜极化过程中，对二维粒子集合在复合扩散合金工作电极上的散射进行成像，将在几分钟内揭示整个样品上的高电化学活性区域，其分辨率为小区域，或者可能更小，一侧小于100微米。这意味着一个由一平方厘米大小的样本组成的图书馆将拥有104个样本。该项目重点研究水溶液中的析氧反应，作为测试电化学反应。这种反应是高度不可逆的，几十年来一直引起人们的极大兴趣。更广泛的意义和重要性：人们对开发高通量方法来加速研究有着广泛的兴趣。该项目的重点是开发一种高通量方法，用于研究电化学反应，这对于实现氢作为燃料的供应至关重要。该项目将使寻找用于分解水以产生氢和纯氧的新电极材料的生产力提高数千倍成为可能。成像安培法的概念可能是解决这一问题的最佳方案；如果是这样，该方法将被其他实验室采用，并且/或者由电化学仪器公司或初创公司开发科学仪器。本研究除了具有丰富的教育研究内容外，还具有在能力方面获得巨大回报的潜力。

1133082PI: SidesTechnical description: The core hypothesis of this project is that colloidal particles can function as probes of local electrochemical current density. The essence of the innovation is using scattered light from colloidal particles during polarization of electrodes. In experiments, colloidal particles will be scattered across test electrodes used in electrochemical cells. Laser radiation introduced at an angle of incidence greater than a critical angle will create evanescent radiation proximate to the electrodes. The particles scatter these evanescent waves as visible light. The particles respond dynamically to local current density, which means that the particles transduce the local current density to light having an intensity that can be measured. Theory will convert the light intensity to a determination of current density. When ensembles of particles are used, the method creates an image of current density on the electrode. Imaging the scattering of a 2D ensemble of particles on a composition spread alloy working electrode during polarization of the film will reveal the regions of high electrochemical activity over the entire sample within minutes, with a resolution of areas as small, or perhaps smaller, than 100 microns on a side. This will mean that a library made from a sample one square centimeter in area will have 104 samples in its collection. The project focuses on oxygen evolution from aqueous solution as the test electrochemical reaction. This reaction is highly irreversible and has been of considerable interest for decades. Broader significance and importance: There is broad interest in developing high throughput methods for accelerating research. This project focuses on development of a high throughput method for investigation of an electrochemical reaction that is critical to enabling the supply of hydrogen as a fuel. The project will make possible a thousandfold increase in productivity in the search for new electrode materials for carrying out the splitting of water to produce hydrogen and pure oxygen. The concept of imaging amperometry might be the best solution to this problem; if so, the method will be adopted at other laboratories and/or a scientific instrument will be developed by an electrochemical instrument company or a startup. The proposed research has the potential for a large payoff in capability in addition to the richness of its research in education.