Graphene-Based Composites for Thermoelectric Applications at Room Temperature
The thermoelectric materials that operate at room temperature represent a scientific challenge in finding chemical compositions with three optimized, independent parameters, namely electrical and thermal conductivity and the Seebeck coefficient. Here, we explore the concept of the formation of hybri...
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| Format: | Article |
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MDPI AG
2023-11-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/16/23/7262 |
| _version_ | 1797399939343450112 |
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| author | Sonya Harizanova Vassil Vulchev Radostina Stoyanova |
| author_facet | Sonya Harizanova Vassil Vulchev Radostina Stoyanova |
| author_sort | Sonya Harizanova |
| collection | DOAJ |
| description | The thermoelectric materials that operate at room temperature represent a scientific challenge in finding chemical compositions with three optimized, independent parameters, namely electrical and thermal conductivity and the Seebeck coefficient. Here, we explore the concept of the formation of hybrid composites between carbon-based materials and oxides, with the aim of modifying their thermoelectric performance at room temperature. Two types of commercially available graphene-based materials are selected: N-containing reduced graphene oxide (NrGO) and expanded graphite (ExGr). Although the NrGO displays the lowest thermal conductivity at room temperature, the ExGr is characterized by the lowest electrical resistivity and a negative Seebeck coefficient. As oxides, we choose two perspective thermoelectric materials: p-type Ca<sub>3</sub>Co<sub>4</sub>O<sub>9</sub> and n-type Zn<sub>0.995</sub>Al<sub>0.005</sub>O. The hybrid composites were prepared by mechanical milling, followed by a pelleting. The thermoelectric efficiency was evaluated on the basis of its measured electrical resistivity, Seebeck coefficient and thermal conductivity at room temperature. It was found that that 2 wt.% of ExGr or NrGO leads to an enhancement of the thermoelectric activity of Ca<sub>3</sub>Co<sub>4</sub>O<sub>9</sub>, while, for Zn<sub>0.995</sub>Al<sub>0.005</sub>O, the amount of ExGr varies between 5 and 20 wt.%. The effect of the composites’ morphology on the thermoelectric properties is discussed on the basis of SEM/EDS experiments. |
| first_indexed | 2024-03-09T01:48:24Z |
| format | Article |
| id | doaj.art-e49994e0b8ba465cb545b7aa9dcc1e0b |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T01:48:24Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-e49994e0b8ba465cb545b7aa9dcc1e0b2023-12-08T15:20:24ZengMDPI AGMaterials1996-19442023-11-011623726210.3390/ma16237262Graphene-Based Composites for Thermoelectric Applications at Room TemperatureSonya Harizanova0Vassil Vulchev1Radostina Stoyanova2Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, BulgariaFaculty of Physics, University of Sofia, 1164 Sofia, BulgariaInstitute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, BulgariaThe thermoelectric materials that operate at room temperature represent a scientific challenge in finding chemical compositions with three optimized, independent parameters, namely electrical and thermal conductivity and the Seebeck coefficient. Here, we explore the concept of the formation of hybrid composites between carbon-based materials and oxides, with the aim of modifying their thermoelectric performance at room temperature. Two types of commercially available graphene-based materials are selected: N-containing reduced graphene oxide (NrGO) and expanded graphite (ExGr). Although the NrGO displays the lowest thermal conductivity at room temperature, the ExGr is characterized by the lowest electrical resistivity and a negative Seebeck coefficient. As oxides, we choose two perspective thermoelectric materials: p-type Ca<sub>3</sub>Co<sub>4</sub>O<sub>9</sub> and n-type Zn<sub>0.995</sub>Al<sub>0.005</sub>O. The hybrid composites were prepared by mechanical milling, followed by a pelleting. The thermoelectric efficiency was evaluated on the basis of its measured electrical resistivity, Seebeck coefficient and thermal conductivity at room temperature. It was found that that 2 wt.% of ExGr or NrGO leads to an enhancement of the thermoelectric activity of Ca<sub>3</sub>Co<sub>4</sub>O<sub>9</sub>, while, for Zn<sub>0.995</sub>Al<sub>0.005</sub>O, the amount of ExGr varies between 5 and 20 wt.%. The effect of the composites’ morphology on the thermoelectric properties is discussed on the basis of SEM/EDS experiments.https://www.mdpi.com/1996-1944/16/23/7262thermoelectric oxidesexpanded graphitegraphene oxidelayered oxideszinc oxidemultiphase composites |
| spellingShingle | Sonya Harizanova Vassil Vulchev Radostina Stoyanova Graphene-Based Composites for Thermoelectric Applications at Room Temperature Materials thermoelectric oxides expanded graphite graphene oxide layered oxides zinc oxide multiphase composites |
| title | Graphene-Based Composites for Thermoelectric Applications at Room Temperature |
| title_full | Graphene-Based Composites for Thermoelectric Applications at Room Temperature |
| title_fullStr | Graphene-Based Composites for Thermoelectric Applications at Room Temperature |
| title_full_unstemmed | Graphene-Based Composites for Thermoelectric Applications at Room Temperature |
| title_short | Graphene-Based Composites for Thermoelectric Applications at Room Temperature |
| title_sort | graphene based composites for thermoelectric applications at room temperature |
| topic | thermoelectric oxides expanded graphite graphene oxide layered oxides zinc oxide multiphase composites |
| url | https://www.mdpi.com/1996-1944/16/23/7262 |
| work_keys_str_mv | AT sonyaharizanova graphenebasedcompositesforthermoelectricapplicationsatroomtemperature AT vassilvulchev graphenebasedcompositesforthermoelectricapplicationsatroomtemperature AT radostinastoyanova graphenebasedcompositesforthermoelectricapplicationsatroomtemperature |