In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions
Nanoparticle suspensions represent a promising route toward low cost, large area solution deposition of functional thin films for applications in energy conversion, flexible electronics, and sensors. However, parameters such size, stoichiometry, and electronic properties must be controlled to achiev...
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| Format: | Article |
| Language: | English |
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Wiley
2012-01-01
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| Series: | Journal of Nanotechnology |
| Online Access: | http://dx.doi.org/10.1155/2012/195761 |
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| author | Yun-Ju Lee Diego Barrera Kaiyuan Luo Julia W. P. Hsu |
| author_facet | Yun-Ju Lee Diego Barrera Kaiyuan Luo Julia W. P. Hsu |
| author_sort | Yun-Ju Lee |
| collection | DOAJ |
| description | Nanoparticle suspensions represent a promising route toward low cost, large area solution deposition of functional thin films for applications in energy conversion, flexible electronics, and sensors. However, parameters such size, stoichiometry, and electronic properties must be controlled to achieve best results for the target application. In this report, we demonstrate that such control can be achieved via in situ chemical oxidation of MoOx nanoparticles in suspensions. Starting from a microwave-synthesized suspension of ultrasmall (d~2 nm) MoOx nanoparticles in n-butanol, we added H2O2 at room temperature to chemically oxidize the nanoparticles. We systematically varied H2O2 concentration and reaction time and found that they significantly affected oxidation state and work function of MoOx nanoparticle films. In particular, we achieved a continuous tuning of MoOx work function from 4.4 to 5.0 eV, corresponding to oxidation of as-synthesized MoOx nanoparticle (20% Mo6+) to essentially pure MoO3. This was achieved without significantly modifying nanoparticle size or stability. Such precise control of MoOx stoichiometry and work function is critical for the optimization of MoOx nanoparticles for applications in organic optoelectronics. Moreover, the simplicity of the chemical oxidation procedure should be applicable for the development of other transition oxide nanomaterials with tunable composition and properties. |
| format | Article |
| id | doaj-art-44357ed0921f4bad821a1153c4f553cd |
| institution | Kabale University |
| issn | 1687-9503 1687-9511 |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Nanotechnology |
| spelling | doaj-art-44357ed0921f4bad821a1153c4f553cd2025-02-03T05:59:37ZengWileyJournal of Nanotechnology1687-95031687-95112012-01-01201210.1155/2012/195761195761In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in SuspensionsYun-Ju Lee0Diego Barrera1Kaiyuan Luo2Julia W. P. Hsu3Department of Materials Science and Engineering, University of Texas at Dallas, 800 W Campbell Road, RL10, Richardson, TX 75080, USADepartment of Materials Science and Engineering, University of Texas at Dallas, 800 W Campbell Road, RL10, Richardson, TX 75080, USADepartment of Materials Science and Engineering, University of Texas at Dallas, 800 W Campbell Road, RL10, Richardson, TX 75080, USADepartment of Materials Science and Engineering, University of Texas at Dallas, 800 W Campbell Road, RL10, Richardson, TX 75080, USANanoparticle suspensions represent a promising route toward low cost, large area solution deposition of functional thin films for applications in energy conversion, flexible electronics, and sensors. However, parameters such size, stoichiometry, and electronic properties must be controlled to achieve best results for the target application. In this report, we demonstrate that such control can be achieved via in situ chemical oxidation of MoOx nanoparticles in suspensions. Starting from a microwave-synthesized suspension of ultrasmall (d~2 nm) MoOx nanoparticles in n-butanol, we added H2O2 at room temperature to chemically oxidize the nanoparticles. We systematically varied H2O2 concentration and reaction time and found that they significantly affected oxidation state and work function of MoOx nanoparticle films. In particular, we achieved a continuous tuning of MoOx work function from 4.4 to 5.0 eV, corresponding to oxidation of as-synthesized MoOx nanoparticle (20% Mo6+) to essentially pure MoO3. This was achieved without significantly modifying nanoparticle size or stability. Such precise control of MoOx stoichiometry and work function is critical for the optimization of MoOx nanoparticles for applications in organic optoelectronics. Moreover, the simplicity of the chemical oxidation procedure should be applicable for the development of other transition oxide nanomaterials with tunable composition and properties.http://dx.doi.org/10.1155/2012/195761 |
| spellingShingle | Yun-Ju Lee Diego Barrera Kaiyuan Luo Julia W. P. Hsu In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions Journal of Nanotechnology |
| title | In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions |
| title_full | In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions |
| title_fullStr | In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions |
| title_full_unstemmed | In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions |
| title_short | In Situ Chemical Oxidation of Ultrasmall MoOx Nanoparticles in Suspensions |
| title_sort | in situ chemical oxidation of ultrasmall moox nanoparticles in suspensions |
| url | http://dx.doi.org/10.1155/2012/195761 |
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