Polyelectrolyte-Assisted Oxygen Vacancies : A New Route to Defect Engineering in Molybdenum Oxide

The presence of oxygen vacancy sites fundamentally affects physical and chemical properties of materials. In this study, a dipole-containing interaction between poly(diallyldimethylammonium chloride) PDDA and α-MoO3 is found to enable high-concentrations of surface oxygen vacancies. Thermal annealin...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 34(2018), 21 vom: 29. Mai, Seite 6296-6306
1. Verfasser: Yazdani, Sajad (VerfasserIn)
Weitere Verfasser: Kashfi-Sadabad, Raana, Huan, Tran Doan, Morales-Acosta, Mayra Daniela, Pettes, Michael Thompson
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.
LEADER 01000naa a22002652 4500
001 NLM283747005
003 DE-627
005 20231225041619.0
007 cr uuu---uuuuu
008 231225s2018 xx |||||o 00| ||eng c
024 7 |a 10.1021/acs.langmuir.8b00539  |2 doi 
028 5 2 |a pubmed24n0945.xml 
035 |a (DE-627)NLM283747005 
035 |a (NLM)29727580 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Yazdani, Sajad  |e verfasserin  |4 aut 
245 1 0 |a Polyelectrolyte-Assisted Oxygen Vacancies  |b A New Route to Defect Engineering in Molybdenum Oxide 
264 1 |c 2018 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Completed 10.09.2018 
500 |a Date Revised 10.09.2018 
500 |a published: Print-Electronic 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a The presence of oxygen vacancy sites fundamentally affects physical and chemical properties of materials. In this study, a dipole-containing interaction between poly(diallyldimethylammonium chloride) PDDA and α-MoO3 is found to enable high-concentrations of surface oxygen vacancies. Thermal annealing under Ar resulted in negligible reduction of MoO3 to MoO3- x with x = 0.03 at 600 °C. In contrast, we show that the thermochemical reaction with PDDA polyelectrolyte under Ar can significantly reduce MoO3 to MoO3- x with x = 0.36 (MoO2.64) at 600 °C. Thermal annealing under H2 gas enhanced the substoichiometry of MoO3- x from x = 0.62 to 0.98 by using PDDA at the same conditions. Density functional theory calculations, supported by experimental analysis, suggest that the vacancy sites are created through absorption of terminal site oxygen (Ot) upon decomposition of the N-C bond in the pentagonal ring of PDDA during the thermal treatment. Ot atoms are absorbed as ionic O- and neutral O2-, creating Mo5+-vO· and Mo4+-vO·· vacancy bipolarons and polarons, respectively. X-ray photoemission spectroscopy peak analysis indicates the ratio of charged to neutral molybdenum ions in the PDDA-processed samples increased from Mo4+/Mo6+ = 1.0 and Mo5+/Mo6+ = 3.3 when reduced at 400 °C to Mo4+/Mo6+ = 3.7 and Mo5+/Mo6+ = 2.6 when reduced at 600 °C. This is consistent with our ab initio calculation where the Mo4+-vO·· formation energy is 0.22 eV higher than that for Mo5+-vO· in the bulk of the material and 0.02 eV higher on the surface. This study reveals a new paradigm for effective enhancement of surface oxygen vacancy concentrations essential for a variety of technologies including advanced energy conversion applications such as electrochemical energy storage, catalysis, and low-temperature thermochemical water splitting 
650 4 |a Journal Article 
650 4 |a Research Support, Non-U.S. Gov't 
650 4 |a Research Support, U.S. Gov't, Non-P.H.S. 
700 1 |a Kashfi-Sadabad, Raana  |e verfasserin  |4 aut 
700 1 |a Huan, Tran Doan  |e verfasserin  |4 aut 
700 1 |a Morales-Acosta, Mayra Daniela  |e verfasserin  |4 aut 
700 1 |a Pettes, Michael Thompson  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1992  |g 34(2018), 21 vom: 29. Mai, Seite 6296-6306  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:34  |g year:2018  |g number:21  |g day:29  |g month:05  |g pages:6296-6306 
856 4 0 |u http://dx.doi.org/10.1021/acs.langmuir.8b00539  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 34  |j 2018  |e 21  |b 29  |c 05  |h 6296-6306