Exploration of Fast Proton Conductors and their Application to New Type Chemical Sensors

质子导电固体电解质（质子导体）具有一个显著的特性，即只有氢离子（质子）可以作为电载体在固体材料中移动。利用质子导体的这一特性，这些材料可以替代传统的液体电解质应用于新的功能器件。特别是在化学传感器方面，质子导体的使用可以使开发新型全固态化学传感器成为可能，如无绳传感器，微型传感器和智能传感器。在本研究中，我们首先进行探索具有高离子导电性以及高稳定性的优良质子导体，并阐明质子导体的导电机制。在此基础上，我们尝试研制了一种新型的质子导体化学传感器，其主要结果如下：（1）在所研究的各种无机离子交换剂中，锑酸和反锑酸是最好的离子交换剂 ...更多信息 发现任何磷酸盐具有相对高的质子传导性和热稳定性和化学稳定性。(2)对锑酸质子传导机理的研究表明，随着吸附水量的增加，锑酸质子传导机理由跳跃型转变为Grotthus型。(3)新设计了一种四探针型传感器元件，其中嵌入了两个银探针。传感器信号（两个探头之间的内部电位差）被发现不仅对湿度不敏感，而且与空气中的氢浓度成正比。(4)为了提高质子导体传感器对空气中CO的气体选择性，用氧化物电极如WO_3和SnO_2代替Pt电极是非常有效的。(5)采用Nafion膜和锑酸厚膜的电流型质子导体传感器可同时检测水中的气态氧和溶解氧。这些传感器将被应用于生物传感器的换能器。(6)采用丝网印刷法和旋涂法制备的锑酸厚膜传感器元件在室温下对空气中的H_2气体具有良好的敏感特性。这样的厚膜型传感器将与小型化以及简化兼容。少

Protonic conducting solid electrolytes (proton conductors) have a remarkable characteristic that only hydrogen ions (protons) can move through the solid material as electrical carriers. By using this property of proton conductors, these materials can be applied to new functional devices in place of conventional liquid electrolytes. Especially in the case of chemical sensors, the use of proton conductors can make it possible to develop new types of all-solid-state chemical sensors, such as cordless sensors, micro sensors, and intelligent sensors. In this study, we first conducted to explore excellent proton conductors with high ionic conductivity as well as high stability, and to clarify the conduction mechanism of proton conductors. Then, we tried to develop new type chemical sensors using proton conductors which can be operated at room temperature.The results obtained in this study are summarized as follows: (1) Among various inorganic ionexchangers examined, antimonic acid and antimo … More ny phosphate were found to have relatively high protonic conductivity and thermal- and chemical-stability. (2) The investigation of protonic conduction mechanism in antimonic acid clarified that the mechanism changed from a hopping-type to a Grotthus-type with an increase in the amounts of adsorbed water. (3) A four-probe type sensor element in which two silver probes were embedded was newly designed. The sensor signal (internal potential difference between two probes) was found to be not only insensitive to humidity but also proportional to hydrogen concentration in air. (4) In order to improve gas selectivity to CO in air of the proton conductor sensor, the use of oxide electrodes, such as WO_3 and SnO_2 in place of Pt electrode, was found to be very effective. (5) The amperometric proton conductor sensors using Nafion membrane and antimonic-acid thick-film could detect both gaseous oxygen and dissolved oxygen in water. These sensors would be applied to transducers of biosensors. (6) The sensor elements using antimonic-acid thick-film fabricated by means of screen-printing method or spin-coating method showed excellent sensing characteristics to H_2 in air at room temperature. Such a thick-film type sensor would be compatible to miniaturization as well as simplification. Less