The recently observed helicity-sensitive response, occurring in graphene based field-effect transistors (FETs) is interpreted as a result of the intrinsic phase asymmetry of these devices and interference of plasmons in the FET channel. The graphene-based plasmonic interferometers presented in this work enable the room temperature detection of THz radiation as well as allows us to distinguish between the rotation direction of circular polarized waves. To illustrate the broadband nurture of the observed effects, similar measurements were carried out at both THz and mid-infrared frequencies. The precise control of the carriers type and their concentration throughout the channel length allows us to demonstrate the helicity-sensitive response over a wide range of the gate potentials (from negative to positive values). We experimentally show that the formation of p–n junction inside the graphene channel leads to additional scattering of excited plasma waves, resulting in the suppression of their interference and consequent reduction of the helicity-sensitive contribution.
{"title":"Suppression of plasmonic interference in helicity sensitive broadband terahertz detectors","authors":"Ilya Mazurenko , Dmitriy Vovk , Yakov Matyushkin , Alesia Paddubskaya , Maxim Rybin , Elena Obraztsova","doi":"10.1016/j.cartre.2024.100331","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100331","url":null,"abstract":"<div><p>The recently observed helicity-sensitive response, occurring in graphene based field-effect transistors (FETs) is interpreted as a result of the intrinsic phase asymmetry of these devices and interference of plasmons in the FET channel. The graphene-based plasmonic interferometers presented in this work enable the room temperature detection of THz radiation as well as allows us to distinguish between the rotation direction of circular polarized waves. To illustrate the broadband nurture of the observed effects, similar measurements were carried out at both THz and mid-infrared frequencies. The precise control of the carriers type and their concentration throughout the channel length allows us to demonstrate the helicity-sensitive response over a wide range of the gate potentials (from negative to positive values). We experimentally show that the formation of <em>p–n</em> junction inside the graphene channel leads to additional scattering of excited plasma waves, resulting in the suppression of their interference and consequent reduction of the helicity-sensitive contribution.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000129/pdfft?md5=2dedc3489b545f6a0608bd861ae7bc37&pid=1-s2.0-S2667056924000129-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139999119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1016/j.cartre.2024.100336
Haftom Weldekidan , Amar K. Mohanty , Lawrence T. Drzal , Manjusri Misra
In this paper, we report a method for achieving high-yield graphene-containing biocarbon from burlap waste through a simple two-step carbonization process. The first step involves feedstock carbonization at 600 °C, followed by ball milling and then graphitization at 1200 °C using KOH. A comparative analysis between the obtained bio-graphene and commercial graphene revealed superior graphene properties of the burlap-based graphene. Notably, this bio-based graphene exhibited exceptional characteristics such as a very high BET surface area in the range of 1021 m²/g, low defect-to-graphene ratio of 0.12 in the Raman spectra, and an overall yield of 19% wt. These findings highlight the potential of burlap waste as a sustainable precursor for high-quality graphene synthesis and its potential for various applications.
在本文中,我们报告了一种通过简单的两步碳化工艺从麻布废料中获得高产率含石墨烯生物碳的方法。第一步是在 600 °C 下对原料进行碳化,然后进行球磨,最后在 1200 °C 下使用 KOH 进行石墨化。对所获得的生物石墨烯和商用石墨烯进行比较分析后发现,麻布基石墨烯具有更优越的石墨烯特性。值得注意的是,这种生物基石墨烯表现出非常优异的特性,如 BET 表面积非常高,达到 1021 m²/g,拉曼光谱中缺陷与石墨烯的比率低至 0.12,总体产量达到 19%(重量比)。这些发现凸显了麻布废料作为高质量石墨烯合成的可持续前驱体的潜力及其在各种应用领域的潜力。
{"title":"Graphene-containing biocarbon from burlap waste: Property comparison with commercial grade graphene nanoplatelets","authors":"Haftom Weldekidan , Amar K. Mohanty , Lawrence T. Drzal , Manjusri Misra","doi":"10.1016/j.cartre.2024.100336","DOIUrl":"10.1016/j.cartre.2024.100336","url":null,"abstract":"<div><p>In this paper, we report a method for achieving high-yield graphene-containing biocarbon from burlap waste through a simple two-step carbonization process. The first step involves feedstock carbonization at 600 °C, followed by ball milling and then graphitization at 1200 °C using KOH. A comparative analysis between the obtained bio-graphene and commercial graphene revealed superior graphene properties of the burlap-based graphene. Notably, this bio-based graphene exhibited exceptional characteristics such as a very high BET surface area in the range of 1021 m²/g, low defect-to-graphene ratio of 0.12 in the Raman spectra, and an overall yield of 19% wt. These findings highlight the potential of burlap waste as a sustainable precursor for high-quality graphene synthesis and its potential for various applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000178/pdfft?md5=5bb91e4e21e4b4afdea6f34fcf22b902&pid=1-s2.0-S2667056924000178-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140085561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphene has been used as a catalyst to reduce the energy barrier for corannulene inversion. For such a catalytic study, corannulene structures are normally assumed to already be in close proximity to graphene, either in the concave-up or concave-down orientation. Here we use both the Lennard-Jones potential (pair-wise dispersion model) and density functional theory calculations to show that corannulene at a distance further away from graphene can adopt various orientations to optimise its interaction with graphene.
{"title":"Adsorption of corannulene on graphene","authors":"Panyada Sripaturad , Ngamta Thamwattana , Amir Karton , Kyle Stevens , Duangkamon Baowan","doi":"10.1016/j.cartre.2024.100334","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100334","url":null,"abstract":"<div><p>Graphene has been used as a catalyst to reduce the energy barrier for corannulene inversion. For such a catalytic study, corannulene structures are normally assumed to already be in close proximity to graphene, either in the concave-up or concave-down orientation. Here we use both the Lennard-Jones potential (pair-wise dispersion model) and density functional theory calculations to show that corannulene at a distance further away from graphene can adopt various orientations to optimise its interaction with graphene.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000154/pdfft?md5=f242af02db43d729115bbd47ad069328&pid=1-s2.0-S2667056924000154-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140067515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1016/j.cartre.2024.100335
Aref Arabsahebi , Parisa Akbarian , Mehdi Kheirmand
Carbon fiber paper is one of the most important substrates used in the gas diffusion layer of the polymer electrolyte membrane fuel cell. A novel approach to creating carbon fiber paper using polyacrylonitrile compounds was proposed in this study. The technique incorporated varying amounts of carbon materials, including carbon black (Vulcan), graphite powder, and carbon nanotubes. Polyacrylonitrile carbon materials were prepared through the spinning process, followed by oxidative stabilization under an oxygen atmosphere at a temperature range of 160–300 °C as the first step. The pliable material undergoes a conversion process to create a compound or ladder that is non-plastic, which is then stabilized in an N2 atmosphere. The fibers are then pre-carbonized at temperatures ranging from 300 to 600 °C and further carbonized between 600 and 1100 °C. After that, Teflon is added and the resulting fibers are made into sheets during the production process. Finally, physical measurements and electrochemical methods such as: checking the amount of water absorption, scanning electron microscope (SEM), chronopotentiometry, electrochemical impedance spectroscopy, electron resistance of carbon sheet, double layer capacitance, and surface roughness parameter were evaluated. The results indicate that the best performance is related to CP7 carbon paper (with a 30–70 % combination of polyacrylonitrile and carbon black).
碳纤维纸是聚合物电解质膜燃料电池气体扩散层最重要的基材之一。本研究提出了一种利用聚丙烯腈化合物制造碳纤维纸的新方法。该技术加入了不同数量的碳材料,包括碳黑(Vulcan)、石墨粉和碳纳米管。聚丙烯腈碳材料是通过纺丝工艺制备的,第一步是在 160-300 °C 的氧气环境下进行氧化稳定。柔韧的材料经过转换过程生成非塑料的化合物或阶梯,然后在氮气环境中稳定。然后在 300 至 600 °C 的温度下对纤维进行预碳化,并在 600 至 1100 °C 的温度下进一步碳化。然后,在生产过程中加入聚四氟乙烯并将纤维制成薄片。最后,对物理测量和电化学方法进行了评估,例如:检查吸水率、扫描电子显微镜(SEM)、计时电位计、电化学阻抗光谱、碳片电子电阻、双层电容和表面粗糙度参数。结果表明,性能最好的是 CP7 碳纸(聚丙烯腈和碳黑的比例为 30-70%)。
{"title":"Carbon fiber paper based on composites of carbon and polyacrylonitrile for fuel cell application","authors":"Aref Arabsahebi , Parisa Akbarian , Mehdi Kheirmand","doi":"10.1016/j.cartre.2024.100335","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100335","url":null,"abstract":"<div><p>Carbon fiber paper is one of the most important substrates used in the gas diffusion layer of the polymer electrolyte membrane fuel cell. A novel approach to creating carbon fiber paper using polyacrylonitrile compounds was proposed in this study. The technique incorporated varying amounts of carbon materials, including carbon black (Vulcan), graphite powder, and carbon nanotubes. Polyacrylonitrile carbon materials were prepared through the spinning process, followed by oxidative stabilization under an oxygen atmosphere at a temperature range of 160–300 °C as the first step. The pliable material undergoes a conversion process to create a compound or ladder that is non-plastic, which is then stabilized in an N<sub>2</sub> atmosphere. The fibers are then pre-carbonized at temperatures ranging from 300 to 600 °C and further carbonized between 600 and 1100 °C. After that, Teflon is added and the resulting fibers are made into sheets during the production process. Finally, physical measurements and electrochemical methods such as: checking the amount of water absorption, scanning electron microscope (SEM), chronopotentiometry, electrochemical impedance spectroscopy, electron resistance of carbon sheet, double layer capacitance, and surface roughness parameter were evaluated. The results indicate that the best performance is related to CP7 carbon paper (with a 30–70 % combination of polyacrylonitrile and carbon black).</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000166/pdfft?md5=2b4035665bafe9986ebd6fe7c3f54123&pid=1-s2.0-S2667056924000166-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140061851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1016/j.cartre.2024.100333
Pitambar Poudel, Aaron T. Marshall
In this study, two heterocyclic compounds, 2,2-dimethyl-1,3-dioxane-4,6‑dione (DMDO) and 2,2,5-trimethyl-1,3-dioxane-4,6‑dione (5-DMDO), were thermally decomposed in an inert atmosphere of nitrogen to obtain oxygen functionalized carbon. The decomposition of these compounds was investigated by thermal gravimetric analysis (TGA) and gas chromatography-mass spectroscopy (GCMS) as well as hybrid-density functional theory (h-DFT). DMDO was found to have better thermal stability compared to 5-DMDO and thus gave a higher yield of carbon after decomposition at 1000 °C. This experimental observation was supported by the h-DFT analysis of the energy barriers of the two decomposition mechanisms proposed from the initial decomposition products detected above 100 °C with GCMS analysis and the thermodynamic spontaneity of the final product (solid carbon) at 800 to 1000 °C with TGA. X-ray photoelectron spectroscopy, scanning electron microscopy / energy dispersion spectroscopy and cyclic voltammetry were used to characterize the carbon and evidence was found to suggest that the electrochemical activity of the material towards the [Fe(CN)6]4−/[Fe(CN)6]3- redox couple was dependent on the oxygen content of the carbon.
本研究在氮气惰性气氛中对两种杂环化合物--2,2-二甲基-1,3-二恶烷-4,6-二酮(DMDO)和 2,2,5-三甲基-1,3-二恶烷-4,6-二酮(5-DMDO)进行了热分解,以获得氧官能化碳。热重分析(TGA)、气相色谱-质谱(GCMS)和混合密度泛函理论(h-DFT)对这些化合物的分解进行了研究。研究发现,与 5-DMDO 相比,DMDO 具有更好的热稳定性,因此在 1000 °C 下分解后产生的碳更多。根据 GCMS 分析在 100 °C 以上检测到的初始分解产物以及 TGA 分析在 800 至 1000 °C 下最终产物(固态碳)的热力学自发性,对两种分解机制的能量势垒进行了 h-DFT 分析,从而支持了这一实验观察结果。利用 X 射线光电子能谱、扫描电子显微镜/能量色散光谱和循环伏安法对碳进行了表征,发现有证据表明该材料对[Fe(CN)6]4-/[Fe(CN)6]3-氧化还原对偶的电化学活性取决于碳中的氧含量。
{"title":"Oxygen functionalized carbon obtained from pyrolysis of heterocyclic compounds with their decomposition mechanism","authors":"Pitambar Poudel, Aaron T. Marshall","doi":"10.1016/j.cartre.2024.100333","DOIUrl":"10.1016/j.cartre.2024.100333","url":null,"abstract":"<div><p>In this study, two heterocyclic compounds, 2,2-dimethyl-1,3-dioxane-4,6‑dione (DMDO) and 2,2,5-trimethyl-1,3-dioxane-4,6‑dione (5-DMDO), were thermally decomposed in an inert atmosphere of nitrogen to obtain oxygen functionalized carbon. The decomposition of these compounds was investigated by thermal gravimetric analysis (TGA) and gas chromatography-mass spectroscopy (GCMS) as well as hybrid-density functional theory (h-DFT). DMDO was found to have better thermal stability compared to 5-DMDO and thus gave a higher yield of carbon after decomposition at 1000 °C. This experimental observation was supported by the h-DFT analysis of the energy barriers of the two decomposition mechanisms proposed from the initial decomposition products detected above 100 °C with GCMS analysis and the thermodynamic spontaneity of the final product (solid carbon) at 800 to 1000 °C with TGA. X-ray photoelectron spectroscopy, scanning electron microscopy / energy dispersion spectroscopy and cyclic voltammetry were used to characterize the carbon and evidence was found to suggest that the electrochemical activity of the material towards the [Fe(CN)<sub>6</sub>]<sup>4−</sup>/[F<em>e</em>(CN)<sub>6</sub>]<sup>3-</sup> redox couple was dependent on the oxygen content of the carbon.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000142/pdfft?md5=ed12cfa9cc6c7c5f70a674995b0c60dc&pid=1-s2.0-S2667056924000142-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139965637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Axitinib, marketed as Inlyta, finds various medical applications in the treatment of conditions such as breast cancer, myeloid leukemia, and juvenile myelomonocytic leukemia. Initially, the synthesis of this cytidine analog, and its deoxy derivative decitabine, was carried out in Czechoslovakia to explore their potential as chemotherapeutic agents for cancer treatment. Recent research has been focused on understanding the reactivity and chemical structure of Axitinib, which are believed to contribute to its anticancer properties. As part of this investigation, the adsorption process of Axitinib onto a fullerene (C60) adsorbent in the gas and water phases was examined using the DFT/B3LYP/6-311+G(d, p) method. This analysis involved the assessment of the adsorption energy and a chemical perspective on the interaction between Axitinib and the adsorbent molecule. Furthermore, various thermodynamic characteristics, including Gibbs free energy (-4004.73 kJ), Enthalpy (-4004.52 kJ), and Entropy (709.79 J/mol-kelvin), as well as thermodynamic capacity (349.69 J/mol-kelvin), were calculated. Additionally, key electronic parameters, such as σ(0.20), µ(-2.97), ω(0.88), χ(2.97), and η(5.01) (all in eV), were estimated to elucidate the compound's chemical properties. The calculation of the HOMO (-7.99 eV) and LUMO (2.04 eV) energy levels revealed six regions of chemical activity for Axitinib, confirming its thermodynamic stability and indicating the significance of this adsorption process in delivering Axitinib to biological mechanisms.
{"title":"Theoretical investigation of fullerene (C60) as nano carrier for anti-cancer drug Axitinib","authors":"Saied Jamaladdin Emamjome Koohbanani, Sayed Ali Ahmadi, Dadkhoda Ghazanfari, Enayatollah Sheikhhosseini","doi":"10.1016/j.cartre.2024.100332","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100332","url":null,"abstract":"<div><p>Axitinib, marketed as Inlyta, finds various medical applications in the treatment of conditions such as breast cancer, myeloid leukemia, and juvenile myelomonocytic leukemia. Initially, the synthesis of this cytidine analog, and its deoxy derivative decitabine, was carried out in Czechoslovakia to explore their potential as chemotherapeutic agents for cancer treatment. Recent research has been focused on understanding the reactivity and chemical structure of Axitinib, which are believed to contribute to its anticancer properties. As part of this investigation, the adsorption process of Axitinib onto a fullerene (C60) adsorbent in the gas and water phases was examined using the DFT/B3LYP/6-311+<em>G</em>(d, p) method. This analysis involved the assessment of the adsorption energy and a chemical perspective on the interaction between Axitinib and the adsorbent molecule. Furthermore, various thermodynamic characteristics, including Gibbs free energy (-4004.73 kJ), Enthalpy (-4004.52 kJ), and Entropy (709.79 J/mol-kelvin), as well as thermodynamic capacity (349.69 J/mol-kelvin), were calculated. Additionally, key electronic parameters, such as σ(0.20), µ(-2.97), ω(0.88), χ(2.97), and η(5.01) (all in eV), were estimated to elucidate the compound's chemical properties. The calculation of the HOMO (-7.99 eV) and LUMO (2.04 eV) energy levels revealed six regions of chemical activity for Axitinib, confirming its thermodynamic stability and indicating the significance of this adsorption process in delivering Axitinib to biological mechanisms.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000130/pdfft?md5=246a669c2aff52e7eaf9a9804cef6f31&pid=1-s2.0-S2667056924000130-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139935350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-17DOI: 10.1016/j.cartre.2024.100330
Aristides D. Zdetsis
In contrast to alternant, in non-alternant nanographenes (NGRs) and graphene nanoribbons (GNRs) no “sublattice structure” can be defined, associated with significant conceptual and computational simplifications. This leads to some fundamental differences between the two. We uncover here the broken electron-hole symmetry in non-alternant NGRs as one fundamental difference closely related to distorted Dirac points (cones) and their diradical open-shell character. We also show by higher level calculations beyond common DFT, based on many-body (MPn) and coupled clusters (CCSD(T)) theory, that the alternant series of peri‑acenes (bisanthene, peri‑tetracene, peri‑pentacene, … etc.), contrary to opposite reports in the literature, have clearly closed singlet ground states, in contrast to their non-alternant isomers based on Stone-Wales (SW) defects. We suggest that this can be experimentally verified by sub-molecularly resolved STM images. The misconceptions in the literature are due to insufficient correlation. For non-alternant SW-NGRs/GNRs with antiaromatic rings the driving force for open-shell states and distorted Dirac points (involving localized electrons and delocalized holes) is antiaromaticity, which is a sufficient but not always necessary condition. This is in juxtaposition to the aromaticity of the alternant isomers with closed shell states. Thus, in both cases sublattice problems, such as sublattice imbalance or complete lack of sublattice would lead to open shell magnetic states; ferromagnetic (e.g. triangulenes), or antiferromagnetic respectively (e.g. SW3 × 2, SW4 × 2), in contrast to non-magnetic (diamagnetic) states for balanced sublattices (e.g. armchair GNRs, AGNRs). Obviously, similar results, regarding the role of antiaromaticity and the broken electron-hole symmetry would be expected for larger NGRs/GNRs obtained by concatenation of such SW-motifs.
{"title":"Open-shell magnetic states in alternant and non-alternant nanographenes: Conceptions and misconceptions","authors":"Aristides D. Zdetsis","doi":"10.1016/j.cartre.2024.100330","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100330","url":null,"abstract":"<div><p>In contrast to alternant, in non-alternant nanographenes (NGRs) and graphene nanoribbons (GNRs) no “sublattice structure” can be defined, associated with significant conceptual and computational simplifications. This leads to some fundamental differences between the two. We uncover here the broken electron-hole symmetry in non-alternant NGRs as one fundamental difference closely related to distorted Dirac points (cones) and their diradical open-shell character. We also show by higher level calculations beyond common DFT, based on many-body (MPn) and coupled clusters (CCSD(T)) theory, that the alternant series of peri‑acenes (bisanthene, peri‑tetracene, peri‑pentacene, … etc.), contrary to opposite reports in the literature, have clearly closed singlet ground states, in contrast to their non-alternant isomers based on Stone-Wales (SW) defects. We suggest that this can be experimentally verified by sub-molecularly resolved STM images. The misconceptions in the literature are due to insufficient correlation. For non-alternant SW-NGRs/GNRs with antiaromatic rings the driving force for open-shell states and distorted Dirac points (involving localized electrons and delocalized holes) is antiaromaticity, which is a sufficient but not always necessary condition. This is in juxtaposition to the aromaticity of the alternant isomers with closed shell states. Thus, in both cases sublattice problems, such as sublattice imbalance or complete lack of sublattice would lead to open shell magnetic states; ferromagnetic (<em>e.g.</em> triangulenes), or antiferromagnetic respectively (<em>e.g.</em> SW3 × 2, SW4 × 2), in contrast to non-magnetic (diamagnetic) states for balanced sublattices (<em>e.g.</em> armchair GNRs, AGNRs). Obviously, similar results, regarding the role of antiaromaticity and the broken electron-hole symmetry would be expected for larger NGRs/GNRs obtained by concatenation of such SW-motifs.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000117/pdfft?md5=52d4d955a2d47fbe998375cc01ad88e7&pid=1-s2.0-S2667056924000117-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139935349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-09DOI: 10.1016/j.cartre.2024.100329
Julien Lemieux , Imran Aslam , Vincent Lemmens , Guy Van den Mooter , Gordana Backović , Samuel Eyley , Wim Thielemans
Insect biomass, rich in chitin and chitosan, is a sustainable and abundant resource with substantial promise for advancing green energy storage solutions. In this study, we explored cricket flour as a biomass candidate for carbon electrodes in electrochemical capacitors, aiming at creating a material with a high nitrogen content upon carbonization. The optimized material boasted a specific surface area exceeding 3300 m2/g, with most pores falling within the 0.5–2 nm diameter range. In a symmetrical Swagelok-type cell, this material delivered exceptional performance, yielding capacitances of 273.5 F/g, 200.2 F/g, and 161.6 F/g at 1 A/g in 6 M KOH, 1 M H2SO4, and 9.2 M NaClO4 electrolytes, respectively. Furthermore, it showcased a capacity retention of 89.6 % and 87.9 % over 5000 cycles in 1 M H2SO4 and 6 M KOH, respectively. The cricket-based electrochemical capacitor exhibited robust cycling stability, suggesting its suitability for prolonged use. The resulting device demonstrated remarkably high specific capacitance, positioning it as a promising candidate for energy storage applications.
昆虫生物质富含甲壳素和壳聚糖,是一种可持续的丰富资源,在推进绿色能源存储解决方案方面大有可为。在本研究中,我们将蟋蟀粉作为电化学电容器中碳电极的候选生物质进行了探索,目的是在碳化过程中创造一种高氮含量的材料。优化后的材料比表面积超过 3300 m2/g,大部分孔隙直径在 0.5-2 nm 范围内。在对称式世伟洛克电池中,这种材料表现出卓越的性能,在 6 M KOH、1 M H2SO4 和 9.2 M NaClO4 电解质中,1 A/g 时的电容量分别为 273.5 F/g、200.2 F/g 和 161.6 F/g。此外,在 1 M H2SO4 和 6 M KOH 中循环 5000 次后,其容量保持率分别为 89.6% 和 87.9%。这种基于蟋蟀的电化学电容器具有强大的循环稳定性,表明它适合长期使用。由此产生的器件具有极高的比电容,有望成为储能应用的候选器件。
{"title":"Insect-powered electrochemical capacitors: The potential of cricket biomass","authors":"Julien Lemieux , Imran Aslam , Vincent Lemmens , Guy Van den Mooter , Gordana Backović , Samuel Eyley , Wim Thielemans","doi":"10.1016/j.cartre.2024.100329","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100329","url":null,"abstract":"<div><p>Insect biomass, rich in chitin and chitosan, is a sustainable and abundant resource with substantial promise for advancing green energy storage solutions. In this study, we explored cricket flour as a biomass candidate for carbon electrodes in electrochemical capacitors, aiming at creating a material with a high nitrogen content upon carbonization. The optimized material boasted a specific surface area exceeding 3300 m<sup>2</sup>/g, with most pores falling within the 0.5–2 nm diameter range. In a symmetrical Swagelok-type cell, this material delivered exceptional performance, yielding capacitances of 273.5 F/g, 200.2 F/g, and 161.6 F/g at 1 A/g in 6 M KOH, 1 M H<sub>2</sub>SO<sub>4</sub>, and 9.2 M NaClO<sub>4</sub> electrolytes, respectively. Furthermore, it showcased a capacity retention of 89.6 % and 87.9 % over 5000 cycles in 1 M H<sub>2</sub>SO<sub>4</sub> and 6 M KOH, respectively. The cricket-based electrochemical capacitor exhibited robust cycling stability, suggesting its suitability for prolonged use. The resulting device demonstrated remarkably high specific capacitance, positioning it as a promising candidate for energy storage applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000105/pdfft?md5=3c5ff6ccf3e479bbf41f1e4c05373503&pid=1-s2.0-S2667056924000105-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139732647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.1016/j.cartre.2024.100327
Stepan Stehlik , Ondrej Szabo , Ekaterina Shagieva , Daria Miliaieva , Alexander Kromka , Zuzana Nemeckova , Jiri Henych , Jan Kozempel , Evgeny Ekimov , Bohuslav Rezek
Hydrogenated nanodiamonds (NDs) get increasing attention as promising nanomaterial in biology as well as optoelectronics. This study shows how the ND synthesis process and ND size are reflected in their different colloidal/hydration and electronic properties. We employ three different ND types: detonation ND (DND), top-down high-pressure high-temperature ND (TD_HPHT ND) prepared by milling of HPHT monocrystals, and bottom-up high-pressure high-temperature ND (BU_HPHT ND) prepared by HPHT synthesis from chloroadamantane. Zeta potential measurements and Fourier transform infrared spectroscopy analysis (FTIR) reveal the best colloidal stability in neutral to basic pH and the strongest affinity to water for DND. Electrical and FTIR measurements connected with an annealing treatment show a steep increase of electrical conductivity in BU_HPHT ND above 2 nm and reveal different contribution of transfer doping in BU_HPHT ND and TD_HPHT ND despite similar conductivity values (≈ 10−5 S.cm−1). We also confirm the correlation of the ND conductivity with IR transmission at the phonon frequency of the diamond (1330 cm−1). Neutron irradiation of a TD_HPHT ND corroborates the crucial role of structural defects in the above colloidal and electronic properties of hydrogenated nanodiamonds.
{"title":"Electrical and colloidal properties of hydrogenated nanodiamonds: Effects of structure, composition and size","authors":"Stepan Stehlik , Ondrej Szabo , Ekaterina Shagieva , Daria Miliaieva , Alexander Kromka , Zuzana Nemeckova , Jiri Henych , Jan Kozempel , Evgeny Ekimov , Bohuslav Rezek","doi":"10.1016/j.cartre.2024.100327","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100327","url":null,"abstract":"<div><p>Hydrogenated nanodiamonds (NDs) get increasing attention as promising nanomaterial in biology as well as optoelectronics. This study shows how the ND synthesis process and ND size are reflected in their different colloidal/hydration and electronic properties. We employ three different ND types: detonation ND (DND), top-down high-pressure high-temperature ND (TD_HPHT ND) prepared by milling of HPHT monocrystals, and bottom-up high-pressure high-temperature ND (BU_HPHT ND) prepared by HPHT synthesis from chloroadamantane. Zeta potential measurements and Fourier transform infrared spectroscopy analysis (FTIR) reveal the best colloidal stability in neutral to basic pH and the strongest affinity to water for DND. Electrical and FTIR measurements connected with an annealing treatment show a steep increase of electrical conductivity in BU_HPHT ND above 2 nm and reveal different contribution of transfer doping in BU_HPHT ND and TD_HPHT ND despite similar conductivity values (≈ 10<sup>−5</sup> S.cm<sup>−1</sup>). We also confirm the correlation of the ND conductivity with IR transmission at the phonon frequency of the diamond (1330 cm<sup>−1</sup>). Neutron irradiation of a TD_HPHT ND corroborates the crucial role of structural defects in the above colloidal and electronic properties of hydrogenated nanodiamonds.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000087/pdfft?md5=b8e605f7c9d415f6a5bd06b6fe38c442&pid=1-s2.0-S2667056924000087-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139726892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.1016/j.cartre.2024.100328
Isaac K. Tetteh , Ibrahim Issahaku , Antonia Y. Tetteh
The historicity and versatility of activated carbons (ACs) and other carbon derivatives (OCDs) date back to antiquity. This article reviews the recent advances in synthesis, characterization, and environmental applications of these demand-driven adsorbents from biomass and non-biomass sources. It first identifies relevant literature sources and knowledge gaps and then segmentalizes and scrutinizes the theme to elucidate contemporary carbon-based adsorbents. Conventional and advanced syntheses are highlighted. Current trends in adsorbents' characterization and remediation are also presented. The conventional AC synthesis includes one-step or two-step chemical or physical activation or a combinatorial synthesis of the two. Issues in the combinatorics are examined. Advanced techniques such as hydrothermal carbonization/activation and microwave-assisted irradiation are described, which may also involve one-step or two-step procedures. OCDs, including carbon nanotubes, carbon nanofibers, and carbon dots, mainly employ advanced syntheses, for example, nanotechnology. Currently, ACs and OCDs are mainly characterized using advanced techniques like scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), nitrogen (N2) adsorption, and X-ray diffraction (XRD), which elucidate their structures, properties, and potential efficacies. Their applications for removing water, soil, and air pollutants are evaluated. The highest percent removal efficiency was activation type-specific, reflecting the precursor's nature, synthesis method, product properties, and quality. For instance, the chemical activation of neem leaves by H3PO4 activation and Fe nanoparticles from tea extracts were 100% successful for Pb2+and Cr6+, respectively, whereas physical activation of rice husk produced 91.8% success for Cr3+. However, their differential adsorptivities for other metals were moderate, with H3PO4 activation the lowest. Due to the high cost, tedious processes in producing and restoring ACs, and their non-selectiveness, researchers continually search for suitable alternatives, which this review considers. Also, applying artificial intelligence (AI) techniques in advancing novel ACs and OCDs for environmental remediation is discussed. Finally, future research dimensions are proposed.
活性碳(AC)和其他碳衍生物(OCD)的历史性和多功能性可以追溯到古代。本文回顾了这些以需求为导向的生物质和非生物质吸附剂在合成、表征和环境应用方面的最新进展。文章首先确定了相关的文献来源和知识空白,然后对主题进行了细分和审查,以阐明当代的碳基吸附剂。重点介绍了传统和先进的合成方法。此外,还介绍了吸附剂表征和修复方面的当前趋势。传统的 AC 合成包括一步或两步化学或物理活化,或两者的组合合成。对组合合成中的问题进行了研究。介绍了水热碳化/活化和微波辅助辐照等先进技术,这些技术也可能涉及一步或两步程序。包括碳纳米管、碳纳米纤维和碳点在内的 OCD 主要采用先进的合成方法,例如纳米技术。目前,AC 和 OCD 主要采用扫描电子显微镜(SEM)、傅立叶变换红外光谱(FTIR)、热重分析(TGA)、氮(N2)吸附和 X 射线衍射(XRD)等先进技术进行表征,从而阐明其结构、性质和潜在功效。评估了它们在去除水、土壤和空气污染物方面的应用。最高的去除率与活化类型有关,反映了前驱体的性质、合成方法、产品特性和质量。例如,通过 H3PO4 活化楝树叶和从茶叶提取物中提取铁纳米粒子的化学活化法对 Pb2+ 和 Cr6+ 的去除率分别为 100%,而稻壳的物理活化法对 Cr3+ 的去除率为 91.8%。不过,它们对其他金属的吸附性差异不大,其中 H3PO4 活化的吸附性最低。由于 AC 的成本高、生产和还原过程繁琐以及其非选择性,研究人员一直在寻找合适的替代品,本综述对此进行了探讨。此外,还讨论了如何应用人工智能(AI)技术推进新型 AC 和 OCD 的环境修复。最后,提出了未来的研究方向。
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