{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,22]],"date-time":"2025-11-22T18:28:48Z","timestamp":1763836128072,"version":"build-2065373602"},"reference-count":48,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2019,11,1]],"date-time":"2019-11-01T00:00:00Z","timestamp":1572566400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51608286, 51420105015, U1706222"],"award-info":[{"award-number":["51608286, 51420105015, U1706222"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007129","name":"Natural Science Foundation of Shandong province","doi-asserted-by":"publisher","award":["ZR2017ZC0737"],"award-info":[{"award-number":["ZR2017ZC0737"]}],"id":[{"id":"10.13039\/501100007129","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen Durability Center for Civil Engineering, Shenzhen University","award":["GDDCE 18-9"],"award-info":[{"award-number":["GDDCE 18-9"]}]},{"name":"the Source Innovation Program of Qingdao City","award":["17-1-1-13-jch"],"award-info":[{"award-number":["17-1-1-13-jch"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Iridium oxide pH electrodes employing the carbonate melt oxidation method were fabricated with oxidation temperatures of 750 \u00b0C, 800 \u00b0C and 850 \u00b0C, respectively. Scanning electron microscope (SEM) and atomic force microscope (AFM) images showed that the oxide film regularized with the increase in oxidation temperatures. The pH response, response time and long-term stability of the electrodes indicated that the electrodes made at 850 \u00b0C had the best performance. X-ray photoelectron spectra (XPS) surveys investigated the change in the electrodes\u2019 chemical composition and element oxidation states at 850 \u00b0C, and the results showed that the relative content of Ir3+ had increased by 23.9%, and the Ir4+ and Ir6+ had decreased by 10.9% and 13%, respectively, in the surface oxide layer after one month of aging. However, the relative contents of Ir3+, Ir4+ and Ir6+ were almost constant for the inner oxide layer. Meanwhile, the XPS result also indicated that the outer oxide layer of the electrode had a higher hydration degree than the inner oxide layer.<\/jats:p>","DOI":"10.3390\/s19214756","type":"journal-article","created":{"date-parts":[[2019,11,1]],"date-time":"2019-11-01T12:30:50Z","timestamp":1572611450000},"page":"4756","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Effect of Oxidization Temperatures and Aging on Performance of Carbonate Melt Oxidized Iridium Oxide pH Electrode"],"prefix":"10.3390","volume":"19","author":[{"given":"Penggang","family":"Wang","sequence":"first","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"},{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"},{"name":"Shenzhen Durability Center for Civil Engineering, Shenzhen University, Shenzhen 518060, China"}]},{"given":"Tengfei","family":"Guo","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"}]},{"given":"Tiejun","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"},{"name":"Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao 266033, China"}]},{"given":"Zhenxing","family":"Du","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"}]},{"given":"Zuquan","family":"Jin","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"},{"name":"Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao 266033, China"}]},{"given":"Biqin","family":"Dong","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"},{"name":"Shenzhen Durability Center for Civil Engineering, Shenzhen University, Shenzhen 518060, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9379-6789","authenticated-orcid":false,"given":"Zhe","family":"Li","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Liu, X., Niu, D., Li, X., Lv, Y., and Fu, Q. 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