{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T17:54:54Z","timestamp":1775584494005,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2014,6,27]],"date-time":"2014-06-27T00:00:00Z","timestamp":1403827200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Thin films of tungsten trioxide were deposited on quartz substrates by RF magnetron sputtering. Different annealing temperatures in the range from 423 to 973 K were used under ambient atmosphere. The influence of the annealing temperature on the structure and optical properties of the resulting WO3 thin films were studied. The surface morphology of the films is composed of grains with an average size near 70 nm for the films annealed between 773 and 973 K. Some of the WO3 thin films were also coated with Pt nanoparticles of about 45 nm in size. Spectrometric measurements of transmittance were carried out for both types of WO3 samples in the wavelength range from 200\u2013900 nm, to determine the effect of the exposure to two different gases namely H2 and CO. Films showed fast response and recovery times, in the range of few seconds. The addition of Pt nanoparticles enables reducing the operation temperature to room temperature.<\/jats:p>","DOI":"10.3390\/s140711427","type":"journal-article","created":{"date-parts":[[2014,6,27]],"date-time":"2014-06-27T11:23:16Z","timestamp":1403868196000},"page":"11427-11443","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Effect of Pt Nanoparticles on the Optical Gas Sensing Properties of WO3 Thin Films"],"prefix":"10.3390","volume":"14","author":[{"given":"Muhammad","family":"Qadri","sequence":"first","affiliation":[{"name":"Cristal\u00b7lograf\u00eda de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"},{"name":"Dept. d'Enginyeria Electronica i Automatica-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"},{"name":"Microsystems and nanotechnologies for chemical analysis (MINOS-EMaS), Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alex","family":"Diaz","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Industriale,Universita' di Padova,Via Marzolo 9, Padova 35131, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michaela","family":"Cittadini","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Industriale,Universita' di Padova,Via Marzolo 9, Padova 35131, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9601-8640","authenticated-orcid":false,"given":"Alessandro","family":"Martucci","sequence":"additional","affiliation":[{"name":"Dipartimento di Ingegneria Industriale,Universita' di Padova,Via Marzolo 9, Padova 35131, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maria","family":"Pujol","sequence":"additional","affiliation":[{"name":"Cristal\u00b7lograf\u00eda de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Josep","family":"Ferr\u00e9-Borrull","sequence":"additional","affiliation":[{"name":"Dept. d'Enginyeria Electronica i Automatica-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6164-4342","authenticated-orcid":false,"given":"Eduard","family":"Llobet","sequence":"additional","affiliation":[{"name":"Microsystems and nanotechnologies for chemical analysis (MINOS-EMaS), Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Magdalena","family":"Aguil\u00f3","sequence":"additional","affiliation":[{"name":"Cristal\u00b7lograf\u00eda de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francesc","family":"D\u00edaz","sequence":"additional","affiliation":[{"name":"Cristal\u00b7lograf\u00eda de Materials i Nanomaterials (FiCMA-FiCNA)-EMaS, Universitat Rovira i Virgili, (URV), Campus Sescelades, c\/Marcel\u00b7\u00ed Domingo s\/n, Tarragona 43007, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2014,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"508","DOI":"10.1016\/j.snb.2004.11.068","article-title":"Distributed hydrogen determination with fiber-optic sensor","volume":"108","author":"Sumida","year":"2005","journal-title":"Sens. Actuators B"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1016\/j.snb.2007.04.012","article-title":"Ozone monitoring by micro-machined sensors with WO3 sensing films","volume":"126","author":"Vallejos","year":"2007","journal-title":"Sens. Actuators B"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/0927-0248(92)90071-V","article-title":"Preparation conditions of sputtered electrochromic WO3 films and their infrared absorption spectra","volume":"25","author":"Kitao","year":"1992","journal-title":"Sol. Energy Mater. Sol. C"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/S0925-8388(96)02416-4","article-title":"Hydrogen transport through r.f.-magnetron sputtered amorphous and crystalline WO, films","volume":"244","author":"Pyun","year":"1996","journal-title":"J. Alloy. Compd."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/0925-4005(96)80020-7","article-title":"Sensitivity of WO3 thin film obtained by high vacuum thermal evaporation","volume":"31","author":"Cantalini","year":"1996","journal-title":"Sens. Actuators B"},{"key":"ref_6","first-page":"29","article-title":"Structure and properties of electrochromic WO3 produced by sol-gel methods","volume":"1536","author":"Bell","year":"1991","journal-title":"Proc. Soc. Photo Opt. Instrum. Eng. SPIE"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2296","DOI":"10.1557\/JMR.2003.0321","article-title":"Fabrication of nanoporous tungsten oxide by galvanostatic anodization","volume":"18","author":"Mukherjee","year":"2003","journal-title":"J. Mater. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1016\/0022-3093(94)90290-9","article-title":"Characterization of amorphous tungsten trioxide thin films prepared by rf magnetron sputtering method","volume":"178","author":"Nanba","year":"1994","journal-title":"J. Non Cryst. Solids"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.solmat.2007.01.026","article-title":"Opportunities and challenges in science and technology of WO3 forelectrochromic and related applications","volume":"92","author":"Deb","year":"2008","journal-title":"Sol. Energy Mater. Sol. C"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/S0920-5861(96)00206-4","article-title":"Combined effects of small gold particles on the optical gas sensing by transition metal oxide films","volume":"36","author":"Ando","year":"1997","journal-title":"Catal. Today"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/S0925-4005(01)00561-5","article-title":"Optical hydrogen senstivity of noble metal- tungsten oxide composite films prepared by sputtering deposition","volume":"76","author":"Ando","year":"2001","journal-title":"Sens. Actuators B"},{"key":"ref_12","first-page":"3748","article-title":"Fast coloration in sputtered gasochromic tungsten oxide films","volume":"203","author":"Shanak","year":"2006","journal-title":"Phys. Stat. Sol. A"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3843","DOI":"10.1002\/adfm.200800864","article-title":"Gold Nanoparticle-Doped TiO2 Semiconductor Thin Films Gas Sensing Properties","volume":"18","author":"Buso","year":"2008","journal-title":"Adv. Funct. Mater."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.snb.2008.12.035","article-title":"Absorption spectral response of nanotextured WO3 thin films with Pt catalyst towards H2","volume":"137","author":"Yaacob","year":"2009","journal-title":"Sens. Actuators B"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1799","DOI":"10.1016\/j.electacta.2005.12.061","article-title":"Nanostructures from directionally solidified NiAl\u2013W eutectic alloys","volume":"52","author":"Hassel","year":"2006","journal-title":"Electrochim. Acta"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1583","DOI":"10.1021\/cm0403816","article-title":"tmospheric Pressure Chemical Vapor Deposition of Crystalline Monoclinic WO3 and WO3-x Thin Films from Reaction of WCl6 with O-Containing Solvents and Their Photochromic and Electrochromic Properties","volume":"17","author":"Blackman","year":"2005","journal-title":"Chem. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.1016\/j.poly.2006.11.017","article-title":"The APCVD of tungsten oxide thin films from reaction of WCl6 with ethanol and results on their gas-sensing properties","volume":"26","author":"Ashraf","year":"2008","journal-title":"Polyhedron"},{"key":"ref_18","unstructured":"Nau, D., Orzekowsky, R.B., Seidel, A., Meyrath, T.P., and Giessen, H. (2008). A Hydrogen Sensor Based on Metallic Photonic Crystal Slabs. OSA Tech. Dig. Photon. Cryst. Waveguid. Cavit. QFG [CD], QFG2."},{"key":"ref_19","first-page":"1","article-title":"WO3-Au-Pt Nanocrystalline Thin Filmsas Optical Gas","volume":"9","author":"Della","year":"2011","journal-title":"Sens. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2367","DOI":"10.1021\/nl048570a","article-title":"Polyol Synthesis of Platinum Nanoparticles: Control of Morphology with Sodium Nitrate","volume":"4","author":"Herricks","year":"2004","journal-title":"Nano Lett."},{"key":"ref_21","unstructured":"Cullity, B.D. (1978). Element of X-Ray Diffraction, Addison-Wesley."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5972","DOI":"10.1039\/c2nr31443f","article-title":"Cooperative effect of Au and Pt inside TiO2 matrix for optical hydrogen detection at room temperature using surface plasmon spectroscopy","volume":"4","author":"Della","year":"2012","journal-title":"Nanoscale"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1006\/jssc.1996.0051","article-title":"Structural Studies of Tungsten\u2013Titanium Oxide Thin Films","volume":"121","author":"Depero","year":"1996","journal-title":"J. Solid State Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1771","DOI":"10.1016\/j.electacta.2006.01.081","article-title":"Anodic formation of low-aspect-ratio porous alumina films for metal-oxide sensor application","volume":"52","author":"Gorokh","year":"2006","journal-title":"Electrochim. Acta"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.ssi.2003.08.030","article-title":"Optical and electrochromic properties of RF reactively sputtered WO3 films","volume":"165","author":"Washizu","year":"2003","journal-title":"Solid State Ionics"},{"key":"ref_26","unstructured":"Rodriguez-Carvajal, J., and Brilluin, L.L. (1998). Short Reference Guide for the Computer Program FULLPROF, CEA-CNRS."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"7382","DOI":"10.1021\/jp000055n","article-title":"In Situ Raman Spectroscopy of Supported Transition Metal Oxide Catalysts: 18O2\u221216O2 Isotopic Labeling Studies","volume":"104","author":"Weckhuysen","year":"2000","journal-title":"J. Phys. Chem. B"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/0022-4596(87)90359-8","article-title":"Infrared and Raman study of WO3 tungsten trioxides and WO3, xH2O tungsten trioxide tydrates","volume":"67","author":"Daniel","year":"1987","journal-title":"J. Solid State Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1557\/S0883769400052465","article-title":"Basic aspects and challenges of semiconductor gas sensors","volume":"24","author":"Shimizu","year":"1999","journal-title":"MRS Bull."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1088\/0957-0233\/8\/3\/003","article-title":"Solid State Gas sensors","volume":"8","author":"Moseley","year":"1997","journal-title":"Meas. Sci. Techn."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.physb.2006.09.010","article-title":"Effect of annealing on structural and optical properties of WO3 thin films prepared by electron-beam coating","volume":"391","author":"Joraid","year":"2007","journal-title":"Phys. B"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2200","DOI":"10.1063\/1.322870","article-title":"Ultrafine metal particles","volume":"47","author":"Granqvist","year":"1976","journal-title":"J. Appl. Phys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2386","DOI":"10.1103\/PhysRevLett.80.2386","article-title":"Lognormal size distributions in particle growth processes without coagulation","volume":"80","author":"Soderlund","year":"1998","journal-title":"Phys. Rev. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1641\/0006-3568(2001)051[0341:LNDATS]2.0.CO;2","article-title":"Log-normal Distributions across the Sciences: Keys and Clues","volume":"51","author":"Limpert","year":"2001","journal-title":"BioScience"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1016\/S0009-2614(02)00407-4","article-title":"Hyper-Rayleigh scattering studies of silver, copper, and platinum nanoparticle suspensions","volume":"356","author":"Johnson","year":"2002","journal-title":"Chem. Phys. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.snb.2006.04.004","article-title":"Basics of oxygen and SnO2 interaction; work function change and conductivity measurements","volume":"118","author":"Sahm","year":"2006","journal-title":"Sens. Actuators B"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/S0925-4005(00)00330-0","article-title":"A fiber-optic evanescent-wave hydrogen gas sensor using palladium-supported tungsten oxide","volume":"66","author":"Sekimoto","year":"2000","journal-title":"Sens. Actuators B"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1016\/0925-4005(90)80193-4","article-title":"The Role of Noble Metals in the Chemistry of Solid-state Gas Sensors","volume":"1","author":"Kohl","year":"1990","journal-title":"Sens. Actuators B"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/0925-4005(95)80037-9","article-title":"H2-induced surface and interface potentials on Pd-activated SnO2 sensor films","volume":"28","author":"Mizsei","year":"1995","journal-title":"Sens. Actuators B"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.snb.2011.11.038","article-title":"Low temperature CO sensitive nanostructured WO3 thin films doped with Fe","volume":"162","author":"Ahsan","year":"2012","journal-title":"Sens. Actuators B"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"445501","DOI":"10.1088\/0957-4484\/22\/44\/445501","article-title":"Hydrogen sensing properties of dielectrophoretically assembled SnO2 nanoparticles on CMOS-compatible micro-hotplates","volume":"22","author":"Kwak","year":"2011","journal-title":"Nanotechnology"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/7\/11427\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:13:02Z","timestamp":1760217182000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/14\/7\/11427"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,6,27]]},"references-count":41,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2014,7]]}},"alternative-id":["s140711427"],"URL":"https:\/\/doi.org\/10.3390\/s140711427","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,6,27]]}}}