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

1133082 PI：侧面技术说明：该项目的核心假设是胶体颗粒可以作为局部电化学电流密度的探针。 创新的本质是利用电极极化过程中胶体颗粒的散射光。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电极附近产生渐逝辐射。 粒子将这些倏逝波散射为可见光。 颗粒动态地响应于局部电流密度，这意味着颗粒将局部电流密度传递给具有可测量的强度的光。 理论将光强度转换为电流密度的确定。当使用粒子集合时，该方法在电极上产生电流密度的图像。在膜的极化期间，对在组成散布合金工作电极上的颗粒的2D集合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，其中在一侧上的区域的分辨率小至或可能小于100微米。这将意味着，一个面积为1平方厘米的样本库将拥有104个样本。该项目的重点是从水溶液中析氧作为测试电化学反应。这种反应是高度不可逆的，几十年来一直受到相当大的关注。更广泛的意义和重要性：人们对开发高通量方法以加速研究产生了广泛的兴趣。 该项目的重点是开发一种高通量的方法，用于研究电化学反应，这对实现氢作为燃料的供应至关重要。 该项目将使生产率提高数千倍，以寻找新的电极材料，用于分解水生产氢气和纯氧。成像电流分析法的概念可能是解决这个问题的最佳方案;如果是这样，该方法将被其他实验室采用和/或由电化学仪器公司或初创公司开发科学仪器。拟议中的研究除了丰富其教育研究外，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.