Thermal stability of cobalt oxide thin films and its enhancement by cerium oxide

Kód výsledku v IS VaVaI

RIV/00216208:11320/22:10446936 - isvavai.cz

Výsledek na webu

https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=KZk5M2e9H7

DOI - Digital Object Identifier

10.1016/j.apsusc.2022.153430

Jazyk výsledku

angličtina

Název v původním jazyce

Thermal stability of cobalt oxide thin films and its enhancement by cerium oxide

Popis výsledku v původním jazyce

Thermal stability of Co(3)O(4 )and CeOx-Co3O4 thin films prepared by various "dry " physical techniques is inves-tigated. A model system is represented by well-ordered Co3O4(1 1 1)/Ir(1 0 0), more realistic and industrially relevant Co3O4 thin films were grown by magnetron sputtering and direct oxidation of cobalt. In all cases, combined systems with non-continuous cerium oxide overlayer were prepared and compared to pristine oxides. The thin films were subjected to thermal annealing under vacuum and monitored by X-ray photoelectron spectroscopy (XPS), microscopy (STM or SEM) was used to observe the surface morphology. Thermal reduction of Co3O4 spinel structures to CoO and, eventually, metallic Co depends substantially on layer morphology and type of substrate. Thermal stability of the well-ordered model system is significantly higher than for the high surface area oxides deposited by magnetron sputtering or grown by direct oxidation. In the reduction process, inevitable in many applications utilizing Co3O4, cerium adlayer can act as an efficient stabilizing component, protecting cobalt oxide against reduction and decomposition. There is a temperature dependent synergistic interplay between cerium and cobalt oxides via oxygen transfer involving Co2+/Co3+ and Ce4+/Ce3+ redox pairs. Thermal activation can lead to a formation of surface mixed spinel with higher thermal stability in reducing environments.

Název v anglickém jazyce

Thermal stability of cobalt oxide thin films and its enhancement by cerium oxide

Popis výsledku anglicky

Thermal stability of Co(3)O(4 )and CeOx-Co3O4 thin films prepared by various "dry " physical techniques is inves-tigated. A model system is represented by well-ordered Co3O4(1 1 1)/Ir(1 0 0), more realistic and industrially relevant Co3O4 thin films were grown by magnetron sputtering and direct oxidation of cobalt. In all cases, combined systems with non-continuous cerium oxide overlayer were prepared and compared to pristine oxides. The thin films were subjected to thermal annealing under vacuum and monitored by X-ray photoelectron spectroscopy (XPS), microscopy (STM or SEM) was used to observe the surface morphology. Thermal reduction of Co3O4 spinel structures to CoO and, eventually, metallic Co depends substantially on layer morphology and type of substrate. Thermal stability of the well-ordered model system is significantly higher than for the high surface area oxides deposited by magnetron sputtering or grown by direct oxidation. In the reduction process, inevitable in many applications utilizing Co3O4, cerium adlayer can act as an efficient stabilizing component, protecting cobalt oxide against reduction and decomposition. There is a temperature dependent synergistic interplay between cerium and cobalt oxides via oxygen transfer involving Co2+/Co3+ and Ce4+/Ce3+ redox pairs. Thermal activation can lead to a formation of surface mixed spinel with higher thermal stability in reducing environments.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

GA19-22636S: Nanostrukturní katalyzátory bez přítomnosti drahých kovů pro environmentální a energetické aplikace

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Applied Surface Science

ISSN

0169-4332

e-ISSN

1873-5584

Svazek periodika

593

Číslo periodika v rámci svazku

Aug

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

153430

Kód UT WoS článku

000797927800004

EID výsledku v databázi Scopus

2-s2.0-85130144123