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[{"key": "dc.contributor.advisor", "value": "Lahtinen, Manu", "language": null, "element": "contributor", "qualifier": "advisor", "schema": "dc"}, {"key": "dc.contributor.author", "value": "Kuikka, Terhi", "language": null, "element": "contributor", "qualifier": "author", "schema": "dc"}, {"key": "dc.date.accessioned", "value": "2024-04-30T06:14:22Z", "language": null, "element": "date", "qualifier": "accessioned", "schema": "dc"}, {"key": "dc.date.available", "value": "2024-04-30T06:14:22Z", "language": null, "element": "date", "qualifier": "available", "schema": "dc"}, {"key": "dc.date.issued", "value": "2024", "language": null, "element": "date", "qualifier": "issued", "schema": "dc"}, {"key": "dc.identifier.uri", "value": "https://jyx.jyu.fi/handle/123456789/94574", "language": null, "element": "identifier", "qualifier": "uri", "schema": "dc"}, {"key": "dc.description.abstract", "value": "Fossiilisten polttoaineiden k\u00e4ytt\u00f6 ja siit\u00e4 johtuva hiilidioksidipitoisuuden kasvu ilmakeh\u00e4ss\u00e4 ovat johtaneet ilmastokriisiin, joka aiheuttaa tuhoisia seuraamuksia ymp\u00e4ri maailmaa. Muiden uusiutuvien energiaratkaisujen joukossa vety on tunnustettu yhdeksi painopistealueista puhtaaseen energiaan siirtymisess\u00e4. Jo t\u00e4ll\u00e4 hetkell\u00e4 on k\u00e4yt\u00f6ss\u00e4 useita vedyn tuotantotekniikoita, mutta niist\u00e4 tehokkaimmat pohjautuvat edelleen uusiutumattomiin luonnonvaroihin. Kasvihuonekaasup\u00e4\u00e4st\u00f6jen v\u00e4hent\u00e4miseksi vetysektorin on siksi kehitett\u00e4v\u00e4 nopeasti vihre\u00e4mpi\u00e4 tuotantotekniikoita. T\u00e4ss\u00e4 pro gradu \n-tutkielmassa metalliorgaaniset verkkorakenteet (eng. metal-organic framework, MOF) esitell\u00e4\u00e4n yhten\u00e4 lupaavista ratkaisuista vihre\u00e4n vedyn tuotannossa niiden monien sopivien ominaisuuksien vuoksi. MOF-yhdisteit\u00e4 voidaan esimerkiksi k\u00e4ytt\u00e4\u00e4 valoa absorboivissa elektrodeissa valos\u00e4hk\u00f6kemiallisissa (eng. photoelectrochemical, PEC) kennoissa tarjoten reaktiopinta-alaa, ohjaten s\u00e4hk\u00f6varausten siirtoa ja laajentaen valon absorptiospektri\u00e4. N\u00e4in vety\u00e4 voidaan tuottaa veden halkaisun avulla hy\u00f6dynt\u00e4en energianl\u00e4htein\u00e4 ainoastaan s\u00e4hk\u00f6\u00e4 ja suoraa auringonvaloa. Kokeellisessa osassa syntetisoitiin erilaisia veden halkaisureaktioihin soveltuvia MOF-yhdisteit\u00e4. Aiemmin raportoituja MOF-rakenteita, CuI-(bpy):\u00e4 ja erilaisilla ligandeilla varustettuja Ce-UiO-66- yhdisteit\u00e4 valmistettiin miedoissa reaktio-olosuhteissa, ja Ce-UiO-66:n aminofunktionalisoitua rakennemuotoa \u2013 joka on raportoitu lupaavimmaksi erilaisista Ce-UiO-66-yhdisteist\u00e4 vedyn tuotannossa \u2013 yritettiin kasvattaa fluoriseostetun tinaoksidilasin (FTO) p\u00e4\u00e4ll\u00e4 mahdollista jatkok\u00e4ytt\u00f6\u00e4 varten PEC-kennoissa. Muut tutkimusryhm\u00e4t ovat jo raportoineet erilaisia ZIF-8- ja NH2-MIL-125-MOF-yhdisteit\u00e4, joita on kasvatettu suoraan elektrodimateriaalina toimivan nikkelihuovan (eng. nickel foam, NF) tai FTO:n pinnalle, ja n\u00e4m\u00e4 synteesit toistettiin my\u00f6s t\u00e4ss\u00e4 ty\u00f6ss\u00e4. Yksi hyvin tunnettu MOF-rakenne, NH2-UiO-66, pyrittiin syntetisoimaan yhdist\u00e4m\u00e4ll\u00e4 kahden eri synteesireseptin reaktio-olosuhteet. Sovelletun reaktion tavoitteena oli saavuttaa aiempaa yksinkertaisempi ja nopeampi valmistusmenetelm\u00e4 kyseiselle yhdisteelle. Kokeellisen osuuden synteeseiss\u00e4 k\u00e4ytettiin muun muassa saturaatiokiteytyksi\u00e4, solvo- ja hydrotermisi\u00e4 reaktioita sek\u00e4 refluksointia. Pulverimaiset n\u00e4ytteet karakterisoitiin termogravimetrisella analyysill\u00e4 (TGA) sek\u00e4 jauher\u00f6ntgendiffraktiolla (eng. powder X-ray diffraction, PXRD), ja elektrodin\u00e4ytteille k\u00e4ytettiin n\u00e4iden menetelmien lis\u00e4ksi pyyhk\u00e4isyelektronimikroskopiaa (eng. scanning electron microscopy, SEM), jossa hy\u00f6dynnettiin my\u00f6s energiadispersiivist\u00e4 r\u00f6ntgenspektroskopiaa (eng. energy-dispersive X-ray spectroscopy, EDX) alkuaineiden tunnistamiseksi. Kuitenkin havaittiin, ett\u00e4 n\u00e4m\u00e4 karakterisointimenetelm\u00e4t eiv\u00e4t ole kaikkein sopivimpia elektrodimateriaalien p\u00e4\u00e4lle kasvatettujen rakenteiden tutkimiseen kohdeyhdisteiden nanomittakaavan sek\u00e4 elektrodien makromittakaavan vuoksi. Kyseinen kokoero sai elektrodimateriaalien signaalit peitt\u00e4m\u00e4\u00e4n MOF:ien ja niihin mahdollisesti liittyneiden lis\u00e4aineiden signaalit. Vaikka k\u00e4ytetyt karakterisointimenetelm\u00e4t antoivat hyv\u00e4n yleiskuvan analysoitujen jauhemaisten MOF-n\u00e4ytteiden koostumuksesta, elektrodilla kasvatetut yhdisteet vaativat my\u00f6s edell\u00e4 mainittuja tarkempia analyysitekniikoita, jotka mahdollistavat eri komponenttien rakenteellisten ominaisuuksien tarkastelun my\u00f6s nanoskaalassa.", "language": "fi", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.abstract", "value": "The use of fossil fuels and the resulting increase in CO2 concentrations in the atmosphere have led to a climate crisis that is causing devastating consequences around the globe. Among the other renewable energy solutions, hydrogen is acknowledged to be one of the priority areas in clean energy transition. Today, several hydrogen production technologies are being used, but the most efficient ones are still based on non-renewable resources. Therefore, in order to reduce the greenhouse gas emissions, the hydrogen sector needs to develop greener production technologies fast. In this Master\u2019s thesis, metal-organic frameworks (MOFs) are proposed as a promising solution to green hydrogen production due to their many suitable properties. For example, MOFs can be used in light absorbing photoelectrodes in photoelectrochemical (PEC) cells offering more active sites, directing charge transfers, and expanding the range of light absorption. In this way, hydrogen can be produced via water splitting utilizing only electricity and direct solar radiation as energy sources. In the experimental part, different MOF compounds suitable for water splitting were synthetised. Previously reported MOFs, CuI-(bpy) and Ce-UiO-66 compounds with different ligands were synthetised in mild reaction conditions, and the Ce-UiO-66-NH2 structure \u2013 reported as the most promising for hydrogen production of the Ce-UiO-66 compounds \u2013 was attempted to be grown on a fluorine doped tin oxide (FTO) electrode for the further use in PEC cells. Other research groups have already reported modified ZIF-8 and NH2-MIL-125 MOFs to be directly grown on electrode materials, nickel foam (NF) and FTO respectively, and these syntheses were repeated in this work as well. One well known MOF structure, NH2-UiO-66 was attempted to be synthetised by combining reaction parameters from two different articles for a simpler and faster production. The reactions of the work were carried out as saturation crystallization, solvothermal and hydrothermal reactions and by refluxing. Powdery samples were characterised by thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD), and for the electrode samples, TGA, PXRD and scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscopy (EDX) were used. However, it was noticed, that these characterisation methods might not be the most suitable for investigating structures grown on top of the electrode materials, because of the nano scale of the target compounds and the macro scale of the electrodes. This size difference caused the signals of the electrode materials to cover the signals of the MOFs and their possible dopants. Therefore, even if the used characterisation methods give a good overview of the success of known powdery MOF samples, compounds grown on an electrode require other, more precise techniques.", "language": "en", "element": "description", "qualifier": "abstract", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Submitted by Paivi Vuorio (paelvuor@jyu.fi) on 2024-04-30T06:14:22Z\nNo. of bitstreams: 0", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.description.provenance", "value": "Made available in DSpace on 2024-04-30T06:14:22Z (GMT). No. of bitstreams: 0\n Previous issue date: 2024", "language": "en", "element": "description", "qualifier": "provenance", "schema": "dc"}, {"key": "dc.format.extent", "value": "118", "language": "", "element": "format", "qualifier": "extent", "schema": "dc"}, {"key": "dc.format.mimetype", "value": "application/pdf", "language": null, "element": "format", "qualifier": "mimetype", "schema": "dc"}, {"key": "dc.language.iso", "value": "eng", "language": null, "element": "language", "qualifier": "iso", "schema": "dc"}, {"key": "dc.rights", "value": "In Copyright", "language": "en", "element": "rights", "qualifier": null, "schema": "dc"}, {"key": "dc.subject.other", "value": "photoelectrochemical water splitting", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "PEC", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "water splitting", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "MOF", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.subject.other", "value": "metal-organic frameworks", "language": "", "element": "subject", "qualifier": "other", "schema": "dc"}, {"key": "dc.title", "value": "Metal-organic frameworks for photoelectrochemical hydrogen production", "language": null, "element": "title", "qualifier": null, "schema": "dc"}, {"key": "dc.type", "value": "master thesis", "language": null, "element": "type", "qualifier": null, "schema": "dc"}, {"key": "dc.identifier.urn", "value": "URN:NBN:fi:jyu-202404303202", "language": null, "element": "identifier", "qualifier": "urn", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Master\u2019s thesis", "language": "en", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.type.ontasot", "value": "Pro gradu -tutkielma", "language": "fi", "element": "type", "qualifier": "ontasot", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Faculty of Sciences", "language": "en", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.faculty", "value": "Matemaattis-luonnontieteellinen tiedekunta", "language": "fi", "element": "contributor", "qualifier": "faculty", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Department of Chemistry", "language": "en", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.department", "value": "Kemian laitos", "language": "fi", "element": "contributor", "qualifier": "department", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "University of Jyv\u00e4skyl\u00e4", "language": "en", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.contributor.organization", "value": "Jyv\u00e4skyl\u00e4n yliopisto", "language": "fi", "element": "contributor", "qualifier": "organization", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Nanoscience", "language": "en", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "dc.subject.discipline", "value": "Nanotiede", "language": "fi", "element": "subject", "qualifier": "discipline", "schema": "dc"}, {"key": "yvv.contractresearch.funding", "value": "0", "language": "", "element": "contractresearch", "qualifier": "funding", "schema": "yvv"}, {"key": "dc.type.coar", "value": "http://purl.org/coar/resource_type/c_bdcc", "language": null, "element": "type", "qualifier": "coar", "schema": "dc"}, {"key": "dc.rights.copyright", "value": "\u00a9 The Author(s)", "language": null, "element": "rights", "qualifier": "copyright", "schema": "dc"}, {"key": "dc.rights.accesslevel", "value": "openAccess", "language": null, "element": "rights", "qualifier": "accesslevel", "schema": "dc"}, {"key": "dc.type.publication", "value": "masterThesis", "language": null, "element": "type", "qualifier": "publication", "schema": "dc"}, {"key": "dc.subject.oppiainekoodi", "value": "4033", "language": null, "element": "subject", "qualifier": "oppiainekoodi", "schema": "dc"}, {"key": "dc.subject.yso", "value": "vety", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "uusiutuvat energial\u00e4hteet", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "hydrogen", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.subject.yso", "value": "renewable energy sources", "language": null, "element": "subject", "qualifier": "yso", "schema": "dc"}, {"key": "dc.format.content", "value": "fulltext", "language": null, "element": "format", "qualifier": "content", "schema": "dc"}, {"key": "dc.rights.url", "value": "https://rightsstatements.org/page/InC/1.0/", "language": null, "element": "rights", "qualifier": "url", "schema": "dc"}]
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