{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T23:50:39Z","timestamp":1762300239451,"version":"build-2065373602"},"reference-count":47,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2022,12,2]],"date-time":"2022-12-02T00:00:00Z","timestamp":1669939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004410","name":"TUBITAK","doi-asserted-by":"publisher","award":["121M681","UID\/05367\/2020"],"award-info":[{"award-number":["121M681","UID\/05367\/2020"]}],"id":[{"id":"10.13039\/501100004410","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["121M681","UID\/05367\/2020"],"award-info":[{"award-number":["121M681","UID\/05367\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemosensors"],"abstract":"<jats:p>The present work aims to investigate the feasibility of utilizing Pt and PtCo alloy ultrathin films as hydrogen gas sensors in order to reduce the cost of the hydrogen gas sensors by using low-cost metallic materials. In this study, ultrathin Pt and PtCo alloy thin films are evaluated for hydrogen sensors. The stoichiometry and structural characterization of the thin films are observed from XPS, SEM, and EDX measurements. The 2-nm-thick Pt and PtCo films deposited by sputtering onto Si\/SiO2 covers homogeneously the surface in an fcc crystalline plane (111). The hydrogen gas-sensing properties of the films are assessed from the resistance measurement between 25 \u00b0C and 150 \u00b0C temperature range, under atmospheres with hydrogen concentration ranging from 10 ppm to 5%. The hydrogen-sensing mechanism of ultrathin PtxCo1-x alloy films can be elucidated with the surface scattering phenomenon. PtCo thin alloy films show better response time than pure Pt thin films, but the alloy films show lower sensor response than pure Pt film\u2019s sensor response. Aside from these experimental investigations, first-principles calculations have also been carried out for bare Pt and Co, and also PtCo alloys. Compared to the theoretical calculations, the sensor response to change decreases with increasing Co content, a result that is compatible with the experimental results. In an attempt to explain the decrease in the sensor response of PtCo alloy films compared to bare Pt film, a variety of different phenomena are discussed, including the shrinking lattice of the structure or dendritic surface structure of PtCo alloy films by the increasing cobalt ratio.<\/jats:p>","DOI":"10.3390\/chemosensors10120512","type":"journal-article","created":{"date-parts":[[2022,12,2]],"date-time":"2022-12-02T03:00:36Z","timestamp":1669950036000},"page":"512","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Hydrogen-Sensing Properties of Ultrathin Pt-Co Alloy Films"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4527-2056","authenticated-orcid":false,"given":"Mustafa","family":"Erkovan","sequence":"first","affiliation":[{"name":"Instituto de Engenharia de Sistemas E Computadores\u2014Microsistemas e Nanotecnologias (INESC MN), 1000-029 Lisbon, Portugal"},{"name":"Instituto Superior Tecnico (IST), Universidade de Lisboa, 1040-001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8472-1651","authenticated-orcid":false,"given":"Caner","family":"Deger","sequence":"additional","affiliation":[{"name":"Department of Physics, Marmara University, Ziverbey, 34722 Istanbul, T\u00fcrkiye"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6913-6529","authenticated-orcid":false,"given":"Susana","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas E Computadores\u2014Microsistemas e Nanotecnologias (INESC MN), 1000-029 Lisbon, Portugal"},{"name":"Instituto Superior Tecnico (IST), Universidade de Lisboa, 1040-001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2123-2938","authenticated-orcid":false,"given":"Necmettin","family":"Kilinc","sequence":"additional","affiliation":[{"name":"Department of Physics, Inonu University, 44280 Malatya, T\u00fcrkiye"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/S1364-0321(02)00004-7","article-title":"Current status of hydrogen energy","volume":"6","author":"Momirlan","year":"2002","journal-title":"Renew. 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