Kinoshita E, Ingman F, Edwall G, Thulin S, Głab S
Departments of Analytical Chemistry and Applied Physics, The Royal Institute of Technology, S-100 44 Stockholm, Sweden.
Talanta. 1986 Feb;33(2):125-34. doi: 10.1016/0039-9140(86)80028-5.
Different ways of making pH-sensing electrodes from monocrystalline or polycrystalline antimony, iridium and palladium have been investigated. Monocrystalline antimony and iridium are superior to the polycrystalline elements with respect to reproducibility between electrodes and stability of the electrode potential over long periods of time. No good palladium/palladium oxide electrode could be obtained by electrochemical oxidation and the thermal preparation method could not take advantage of the properties of the monocrystalline palladium. Therefore, only polycrystalline palladium was used to study this type of electrodes. The different electrodes were compared with respect to the manner of preparation, the pH-response (reproducibility and time response) and the effect that different complexing ligands present in the measuring solutions may have on the electrode response. Also, the redox-response of the electrodes and the effect of different oxygen pressures on the electrode potentials were studied. The monocrystalline antimony electrodes have the best reproducibility and long-term stability but also respond to complexing ligands and to variations in the oxygen pressure. Monocrystalline iridium electrodes can be obtained by continuously cycling the potential between -0.25 and +1.25 V (SCE) in 0.5M sulphuric acid. They do not respond to the complexing ligands tested, and have fairly good long-term stability, but the reproducibility between electrodes is inferior to that of the monocrystalline antimony electrodes. Polycrystalline antimony and iridium electrodes were inferior to the monocrystalline ones. The properties of the palladium electrodes were similar to those of the iridium ones.
人们研究了用单晶或多晶锑、铱和钯制作pH感应电极的不同方法。在电极之间的重现性以及电极电位的长期稳定性方面，单晶锑和铱优于多晶材料。通过电化学氧化无法获得性能良好的钯/钯氧化物电极，且热制备方法无法利用单晶钯的特性。因此，仅使用多晶钯来研究这类电极。对不同电极在制备方式、pH响应（重现性和时间响应）以及测量溶液中存在的不同络合配体可能对电极响应产生的影响方面进行了比较。此外，还研究了电极的氧化还原响应以及不同氧压对电极电位的影响。单晶锑电极具有最佳的重现性和长期稳定性，但也会对络合配体和氧压变化做出响应。单晶铱电极可通过在0.5M硫酸中在-0.25至+1.25V（SCE）之间连续循环电位来获得。它们对所测试的络合配体无响应，具有相当好的长期稳定性，但电极之间的重现性不如单晶锑电极。多晶锑和铱电极不如单晶电极。钯电极的性能与铱电极相似。
