Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing
We report a photonic technique to instantaneously synthesize cobalt oxide reduced graphitic oxide (CoO<sub>x</sub>-rGO) supercapacitor electrodes. The electrode processing is achieved through rapidly heating the precursor material by irradiation of high-energy pulsed mostly visible light...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-03-01
|
| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/11/3/717 |
| _version_ | 1797541636444520448 |
|---|---|
| author | Madhu Gaire Najma Khatoon Douglas Chrisey |
| author_facet | Madhu Gaire Najma Khatoon Douglas Chrisey |
| author_sort | Madhu Gaire |
| collection | DOAJ |
| description | We report a photonic technique to instantaneously synthesize cobalt oxide reduced graphitic oxide (CoO<sub>x</sub>-rGO) supercapacitor electrodes. The electrode processing is achieved through rapidly heating the precursor material by irradiation of high-energy pulsed mostly visible light from a xenon lamp. Due to the short duration of the light pulse, we prepared the electrodes at room temperature instantaneously (ms), thus eliminating the several hours of processing times of the conventional techniques. The as-prepared electrodes exhibited a highly porous morphology, allowing for enhanced ionic transport during electrochemical interactions. The electrochemical properties of the CoO<sub>x</sub>-rGO electrodes were studied in 1 M KOH aqueous electrolyte. The non-rectangular cyclic voltammetry (CV) curves with characteristic redox peaks indicated the pseudocapacitive charge storage mechanism of the electrodes. From the discharge curves at 0.4 mA/cm<sup>2</sup> and 1.6 A/g constant current densities, the electrode showed areal specific capacitance of 17 mF/cm<sup>2</sup> and specific capacitance of 69 F/g, respectively. Cyclic stability was tested by performing 30,000 galvanostatic charge–discharge (GCD) cycles and the electrode exhibited 65% capacitance retention, showing its excellent electrochemical performance and ultra-long cycle life. The excellent electrochemical electrode properties are attributed to the unique processing technique, optimum processing parameters, improved conductivity due to the presence of rGO, and highly porous morphology which offers a high specific surface area. The novel photonic processing we report allows for high-temperature heating of the precursor films achieved via non-radiative recombination of photogenerated electron holes pairs during irradiation. Such extremely quick (ms) heating followed by instantaneous cooling results in the formation of a dense and robust bottom layer of the electrode, resulting in a long cycle life. |
| first_indexed | 2024-03-10T13:18:48Z |
| format | Article |
| id | doaj.art-daa8c7575d5b49e98f32b5677557674c |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T13:18:48Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-daa8c7575d5b49e98f32b5677557674c2023-11-21T10:15:04ZengMDPI AGNanomaterials2079-49912021-03-0111371710.3390/nano11030717Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal ProcessingMadhu Gaire0Najma Khatoon1Douglas Chrisey2Department of Physics and Engineering Physics, School of Science and Engineering, Tulane University, New Orleans, LA 70118, USADepartment of Physics and Engineering Physics, School of Science and Engineering, Tulane University, New Orleans, LA 70118, USADepartment of Physics and Engineering Physics, School of Science and Engineering, Tulane University, New Orleans, LA 70118, USAWe report a photonic technique to instantaneously synthesize cobalt oxide reduced graphitic oxide (CoO<sub>x</sub>-rGO) supercapacitor electrodes. The electrode processing is achieved through rapidly heating the precursor material by irradiation of high-energy pulsed mostly visible light from a xenon lamp. Due to the short duration of the light pulse, we prepared the electrodes at room temperature instantaneously (ms), thus eliminating the several hours of processing times of the conventional techniques. The as-prepared electrodes exhibited a highly porous morphology, allowing for enhanced ionic transport during electrochemical interactions. The electrochemical properties of the CoO<sub>x</sub>-rGO electrodes were studied in 1 M KOH aqueous electrolyte. The non-rectangular cyclic voltammetry (CV) curves with characteristic redox peaks indicated the pseudocapacitive charge storage mechanism of the electrodes. From the discharge curves at 0.4 mA/cm<sup>2</sup> and 1.6 A/g constant current densities, the electrode showed areal specific capacitance of 17 mF/cm<sup>2</sup> and specific capacitance of 69 F/g, respectively. Cyclic stability was tested by performing 30,000 galvanostatic charge–discharge (GCD) cycles and the electrode exhibited 65% capacitance retention, showing its excellent electrochemical performance and ultra-long cycle life. The excellent electrochemical electrode properties are attributed to the unique processing technique, optimum processing parameters, improved conductivity due to the presence of rGO, and highly porous morphology which offers a high specific surface area. The novel photonic processing we report allows for high-temperature heating of the precursor films achieved via non-radiative recombination of photogenerated electron holes pairs during irradiation. Such extremely quick (ms) heating followed by instantaneous cooling results in the formation of a dense and robust bottom layer of the electrode, resulting in a long cycle life.https://www.mdpi.com/2079-4991/11/3/717photonic synthesisspray coatingcobalt oxidespseudocapacitorsynergistic effect |
| spellingShingle | Madhu Gaire Najma Khatoon Douglas Chrisey Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing Nanomaterials photonic synthesis spray coating cobalt oxides pseudocapacitor synergistic effect |
| title | Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing |
| title_full | Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing |
| title_fullStr | Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing |
| title_full_unstemmed | Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing |
| title_short | Preparation of Cobalt Oxide–Reduced Graphitic Oxide Supercapacitor Electrode by Photothermal Processing |
| title_sort | preparation of cobalt oxide reduced graphitic oxide supercapacitor electrode by photothermal processing |
| topic | photonic synthesis spray coating cobalt oxides pseudocapacitor synergistic effect |
| url | https://www.mdpi.com/2079-4991/11/3/717 |
| work_keys_str_mv | AT madhugaire preparationofcobaltoxidereducedgraphiticoxidesupercapacitorelectrodebyphotothermalprocessing AT najmakhatoon preparationofcobaltoxidereducedgraphiticoxidesupercapacitorelectrodebyphotothermalprocessing AT douglaschrisey preparationofcobaltoxidereducedgraphiticoxidesupercapacitorelectrodebyphotothermalprocessing |