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Ahmad H, Khan RA, Koo BH, Alsalme A. Systematic study of physicochemical and electrochemical properties of carbon nanomaterials. RSC Adv 2022; 12:15593-15600. [PMID: 35685184 PMCID: PMC9125983 DOI: 10.1039/d2ra02533g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/16/2022] [Indexed: 11/21/2022] Open
Abstract
Carbon nanomaterials exhibit exceptional properties and broad horizon applications, where graphene is one of the most popular allotropes of this family due to its astounding performance in every stratum vis-à-vis other classical materials. The large surface area of 2630 m2 g−1, high electrical conductivity, and electron mobility of non-toxic graphene nanomaterials serve as the building blocks for supercapacitor studies. In this article, comparative studies are carried out between electrochemically exfoliated graphene sheets (GSs), solvothermally synthesized graphene quantum dots (GQDs) and acid refluxed carbon nanotubes (CNTs) as an energy storage electrode nanomaterial through cyclic voltammetry (CV). The electrochemical properties of the materials are well correlated with the physicochemical characteristics obtained from Raman, Fourier-transform infrared, and absorption spectroscopy. Thin GSs (0.8–1 nm) and small size (6–10 nm) GQDs fabricated by using laboratory-grade 99% purity graphite rods resulted in promising low-cost materials at mass scale as compared to conducting CNTs. The 0D graphene quantum dots proved to be an excellent energy electrode material in an alkaline electrolyte solution compared to other carbon nanomaterials. The distinct characteristic features of GQDs, like superior electrical properties, large surface area, and abundant active sites make them an ideal candidate for utilization in supercapacitors. The GQDs exhibited an enhanced specific capacitance of 113 F g−1 in 6 mol L−1 KOH through cyclic voltammetry. Carbon nanomaterials exhibit exceptional properties and broad horizon applications, where graphene is one of the most popular allotropes of this family due to its astounding performance in every stratum vis-à-vis other classical materials.![]()
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Affiliation(s)
- Hilal Ahmad
- Division of Computational Physics, Institute for Computational Science, Ton Duc Thang University Ho Chi Minh City 700000 Vietnam .,Faculty of Applied Sciences, Ton Duc Thang University Ho Chi Minh City 700000 Vietnam
| | - Rais Ahmad Khan
- Department of Chemistry, College of Science, King Saud University Riyadh 11451 Kingdom of Saudi Arabia
| | - Bon Heun Koo
- School of Materials Science and Engineering, Changwon National University Changwon 51140 Gyeongnam South Korea
| | - Ali Alsalme
- Department of Chemistry, College of Science, King Saud University Riyadh 11451 Kingdom of Saudi Arabia
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Díez-Pascual AM, Sainz-Urruela C, Vallés C, Vera-López S, San Andrés MP. Tailorable Synthesis of Highly Oxidized Graphene Oxides via an Environmentally-Friendly Electrochemical Process. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E239. [PMID: 32013166 PMCID: PMC7075238 DOI: 10.3390/nano10020239] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/19/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022]
Abstract
Graphene oxide (GO) is an attractive alternative to graphene for many applications due to its captivating optical, chemical, and electrical characteristics. In this work, GO powders with a different amount of surface groups were synthesized from graphite via an electrochemical two-stage process. Many synthesis conditions were tried to maximize the oxidation level, and comprehensive characterization of the resulting samples was carried out via elemental analysis, microscopies (TEM, SEM, AFM), X-ray diffraction, FT-IR and Raman spectroscopies as well as electrical resistance measurements. SEM and TEM images corroborate that the electrochemical process used herein preserves the integrity of the graphene flakes, enabling to obtain large, uniform and well exfoliated GO sheets. The GOs display a wide range of C/O ratios, determined by the voltage and time of each stage as well as the electrolyte concentration, and an unprecedented minimum C/O value was obtained for the optimal conditions. FT-IR evidences strong intermolecular interactions between neighbouring oxygenated groups. The intensity ratio of D/G bands in the Raman spectra is high for samples prepared using concentrated H2SO4 as an electrolyte, indicative of many defects. Furthermore, these GOs exhibit smaller interlayer spacing than that expected according to their oxygen content, which suggests predominant oxidation on the flake edges. Results point out that the electrical resistance is conditioned mostly by the interlayer distance and not simply by the C/O ratio. The tuning of the oxidation level is useful for the design of GOs with tailorable structural, electrical, optical, mechanical, and thermal properties.
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Affiliation(s)
- Ana María Díez-Pascual
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Sciences, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain (S.V.-L.); (M.P.S.)
- Institute of Chemistry Research, “Andrés M. del Río” (IQAR), University of Alcalá, Ctra. Madrid- Barcelona Km. 33.6, Alcalá de Henares, 28805 Madrid, Spain
| | - Carlos Sainz-Urruela
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Sciences, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain (S.V.-L.); (M.P.S.)
| | - Cristina Vallés
- Department of Materials and National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK;
| | - Soledad Vera-López
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Sciences, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain (S.V.-L.); (M.P.S.)
- Institute of Chemistry Research, “Andrés M. del Río” (IQAR), University of Alcalá, Ctra. Madrid- Barcelona Km. 33.6, Alcalá de Henares, 28805 Madrid, Spain
| | - María Paz San Andrés
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Faculty of Sciences, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain (S.V.-L.); (M.P.S.)
- Institute of Chemistry Research, “Andrés M. del Río” (IQAR), University of Alcalá, Ctra. Madrid- Barcelona Km. 33.6, Alcalá de Henares, 28805 Madrid, Spain
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