Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing
Semiconducting metal oxide nanocrystals are an important class of materials that have versatile applications because of their useful properties and high stability. Here, we developed a simple route to synthesize nanocrystals (NCs) of copper oxides such as Cu2O and CuO using a hot-soap method, and ap...
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| Language: | English |
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MDPI AG
2019-01-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/19/1/211 |
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| author | Kazuki Mikami Yuta Kido Yuji Akaishi Armando Quitain Tetsuya Kida |
| author_facet | Kazuki Mikami Yuta Kido Yuji Akaishi Armando Quitain Tetsuya Kida |
| author_sort | Kazuki Mikami |
| collection | DOAJ |
| description | Semiconducting metal oxide nanocrystals are an important class of materials that have versatile applications because of their useful properties and high stability. Here, we developed a simple route to synthesize nanocrystals (NCs) of copper oxides such as Cu2O and CuO using a hot-soap method, and applied them to H2S sensing. Cu2O NCs were synthesized by simply heating a copper precursor in oleylamine in the presence of diol at 160 °C under an Ar flow. X-ray diffractometry (XRD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) results indicated the formation of monodispersed Cu2O NCs having approximately 5 nm in crystallite size and 12 nm in colloidal size. The conversion of the Cu2O NCs to CuO NCs was undertaken by straightforward air oxidation at room temperature, as confirmed by XRD and UV-vis analyses. A thin film Cu2O NC sensor fabricated by spin coating showed responses to H2S in dilute concentrations (1–8 ppm) at 50–150 °C, but the stability was poor because of the formation of metallic Cu2S in a H2S atmosphere. We found that Pd loading improved the stability of the sensor response. The Pd-loaded Cu2O NC sensor exhibited reproducible responses to H2S at 200 °C. Based on the gas sensing mechanism, it is suggested that Pd loading facilitates the reaction of adsorbed oxygen with H2S and suppresses the irreversible formation of Cu2S. |
| first_indexed | 2024-04-11T20:38:58Z |
| format | Article |
| id | doaj.art-8358a93764e84ef4b0001a9b9e7082ab |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T20:38:58Z |
| publishDate | 2019-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-8358a93764e84ef4b0001a9b9e7082ab2022-12-22T04:04:17ZengMDPI AGSensors1424-82202019-01-0119121110.3390/s19010211s19010211Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S SensingKazuki Mikami0Yuta Kido1Yuji Akaishi2Armando Quitain3Tetsuya Kida4Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, JapanDepartment of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, JapanDepartment of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, JapanCollege of Cross-Cultural and Multidisciplinary Studies, Kumamoto University, Kumamoto, 860-8555, JapanFaculty of Advanced Science and Technology, Kumamoto University, Kumamoto, 860-8555, JapanSemiconducting metal oxide nanocrystals are an important class of materials that have versatile applications because of their useful properties and high stability. Here, we developed a simple route to synthesize nanocrystals (NCs) of copper oxides such as Cu2O and CuO using a hot-soap method, and applied them to H2S sensing. Cu2O NCs were synthesized by simply heating a copper precursor in oleylamine in the presence of diol at 160 °C under an Ar flow. X-ray diffractometry (XRD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) results indicated the formation of monodispersed Cu2O NCs having approximately 5 nm in crystallite size and 12 nm in colloidal size. The conversion of the Cu2O NCs to CuO NCs was undertaken by straightforward air oxidation at room temperature, as confirmed by XRD and UV-vis analyses. A thin film Cu2O NC sensor fabricated by spin coating showed responses to H2S in dilute concentrations (1–8 ppm) at 50–150 °C, but the stability was poor because of the formation of metallic Cu2S in a H2S atmosphere. We found that Pd loading improved the stability of the sensor response. The Pd-loaded Cu2O NC sensor exhibited reproducible responses to H2S at 200 °C. Based on the gas sensing mechanism, it is suggested that Pd loading facilitates the reaction of adsorbed oxygen with H2S and suppresses the irreversible formation of Cu2S.http://www.mdpi.com/1424-8220/19/1/211gas sensornanocrystalCu2OCuOH2S |
| spellingShingle | Kazuki Mikami Yuta Kido Yuji Akaishi Armando Quitain Tetsuya Kida Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing Sensors gas sensor nanocrystal Cu2O CuO H2S |
| title | Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing |
| title_full | Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing |
| title_fullStr | Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing |
| title_full_unstemmed | Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing |
| title_short | Synthesis of Cu2O/CuO Nanocrystals and Their Application to H2S Sensing |
| title_sort | synthesis of cu2o cuo nanocrystals and their application to h2s sensing |
| topic | gas sensor nanocrystal Cu2O CuO H2S |
| url | http://www.mdpi.com/1424-8220/19/1/211 |
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