Nanostrukturirane tanke plasti $TiO_2$ za elektrokemijsko cepitev vode

Lapajne, Nejc (author), Spreitzer, Matjaž (mentor), Krajnc, Matjaž (co-mentor)

Iskanje novih možnosti in izboljšav na področju alternativnih virov je vse bolj v porastu. Vodik kot gorivo prihodnosti ima pri tem visok potencial. Čisto in okolju neškodljivo pridobivanje vodika je tehnološko zelo zahteven proces. Vzporedno z reakcijo razvijanja vodika poteka reakcija razvijanja kisika, ki pogosto omejuje hitrost reakcije razvijanja vodika in je ključnega pomena pri optimizaciji elektrokemijske cepitve. Magistrska naloga se ukvarja s pripravo katalizatorskih tankih plasti, za namene fotoelektrokemijske cepitve vode, natančneje za reakcijo razvijanja kisika. Kot osrednja tehnika za pripravo omenjenih tankih plasti je bila uporabljena tehnika pulzno laserskega nanašanja. Izbrana sta bila dva različna sistema, na katerih je bila preučevana rast tankih plasti, njihova sestava, struktura in morfologija ter lastnosti. Kot aktivna zgornja plast katalizatorja je bil v obeh primerih uporabljen titanov dioksid. Prav tako je bil v obeh sistemih kot vmesna plast uporabljen lantanov nikelat. V prvem sistemu je bil za substrat uporabljen lantanov aluminat, medtem ko je bil v drugem sistemu za substrat uporabljen platiniziran silicij. Na podlagi analiz s pomočjo XRD, AFM in SEM tehnik so bili optimizirani parametri nanosa TiO2 za oba sistema. V prvem sistemu, kjer je bil kot substrat uporabljen lantanov aluminat je bilo mogoče opaziti epitaksialno rast tankih plasti titanovega dioksida v obliki anatasa. V drugem sistemu, kjer je bil kot substrat uporabljen platiniziran silicij je bilo mogoče opaziti manj urejeno polikristalinično ali teksturirano strukturo tankih plasti titanovega dioksida. Dva tako različna sistema sta bila uporabljena predvsem zaradi primerjave vpliva strukture tankih plasti titanovega dioksida na aktivnost do katalize reakcije razvoja kisika. Najboljša struktura tankih plasti titanovega dioksida je bila opažena pri vzorcih pripravljenih na lantanovem aluminatu, kjer je bilo mogoče opaziti epitaksialno rast titanovega dioksida. Nasprotno pa se je izkazalo pri funkcionalni analizi, kjer so precej boljšo aktivnost do katalize reakcije razvoja kisika izkazali vzorci pripravljeni na platiniziranem siliciju.

• Language: Slovenian
• Keywords: Nanašanje s pulznim laserjem, titanov dioksid, tanke plasti, elektrokemijska cepitev vode
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-150966
• COBISS.SI-ID: 173223939
• Publication date in RUL: 26.09.2023

Secondary language

• Language: English
• Title: Nanostructured $TiO_2$ Thin Films for Electrochemical Water Splitting

Abstract

Research on alternative means of energy production has been on the rise. One of the key elements of clean energy is hydrogen. Clean hydrogen production is technologically speaking a very challenging process. Along with the hydrogen evolution reaction comes the oxygen evolution reaction that is often the limiting factor and it is therefore crucial when optimizing the performance of electrochemical water splitting. The master thesis looks into the production of thin film catalyzers, that could be used in the process of photoelectrochemical water splitting, specifically oxygen evolution reaction. The main technique used in the master thesis to produce such films was pulsed laser deposition. Two different systems were chosen to analyze composition, structure, morphology, and functional properties. Titanium dioxide was used in both systems as the upper active layer. Both systems also used lanthanum nickelate as a conductive middle layer. The first system used lanthanum aluminate as its substrate, whereas the second used platinized silicon. Deposition parameters of TiO2 deposition were optimized based on XRD, AFM, and SEM analysis for each of the systems. In the first system where lanthanum aluminate was used as the substrate, it was possible to observe epitaxial growth of titanium dioxide thin films in the form of anatase. In the second system where platinized silicon was used as the substrate, it was possible to observe a lot less ordered polycrystalline and textured structure of titanium dioxide thin films. Two such different systems were used to get some insight into the dependence of activity towards oxygen evolution reaction on the structure of titanium dioxide thin films. The best structure of titanium dioxide thin films was observed on the samples prepared on lanthanum aluminate substrate, which gave us epitaxial growth of titanium dioxide. The exact opposite was observed when performing the functional analysis of the thin films. It turned out that the activity towards oxygen evolution reaction is a lot better in the samples prepared on platinized silicon.

• Keywords: Pulsed Laser Deposition, Titanium Dioxide, Thin Films, Electrochemical Water Splitting