Pub Date : 2024-07-29DOI: 10.1007/s42823-024-00781-7
Hyojin Jeong, Seunghyeon Jo, Seulah Yang, Songhee Lee, Subramani Surendran, Duong Nguyen Nguyen, Unbeom Baeck, Jung Kyu Kim, Uk Sim, Sooim Shin
Carbon quantum dots (CQDs) are novel nanocarbon materials and widely used nanoparticles. They have gradually gained popularity in various fields due to their abundance, inexpensive cost, small size, ease of engineering, and distinct properties. To determine the antibacterial activity of metal-doped CQDs (metal-CQDs) containing Fe, Zn, Mn, Ni, and Co, we chose Staphylococcus aureus as a representative Gram-positive strain and Escherichia coli as a representative Gram-negative bacterial strain. Paper disc diffusion tests were conducted for the qualitative results, and a cell growth curve was drawn for quantitative results. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and IC50 were measured from cell growth curves. As a result, all of the metal-CQDs showed toxicity against both Gram-positive and Gram-negative bacteria. Furthermore, Gram-negative bacteria was vulnerable to metal-CQDs than Gram-positive bacteria. The toxicity differed concerning the type of metal-CQDs; Mn-CQDs exhibited the highest efficacy. Hence, this study suggested that CQDs can be used as new nanoparticles for antibiotics.
{"title":"Determination of the antibacterial activity of various metal-doped carbon quantum dots","authors":"Hyojin Jeong, Seunghyeon Jo, Seulah Yang, Songhee Lee, Subramani Surendran, Duong Nguyen Nguyen, Unbeom Baeck, Jung Kyu Kim, Uk Sim, Sooim Shin","doi":"10.1007/s42823-024-00781-7","DOIUrl":"https://doi.org/10.1007/s42823-024-00781-7","url":null,"abstract":"<p>Carbon quantum dots (CQDs) are novel nanocarbon materials and widely used nanoparticles. They have gradually gained popularity in various fields due to their abundance, inexpensive cost, small size, ease of engineering, and distinct properties. To determine the antibacterial activity of metal-doped CQDs (metal-CQDs) containing Fe, Zn, Mn, Ni, and Co, we chose <i>Staphylococcus aureus</i> as a representative Gram-positive strain and <i>Escherichia coli</i> as a representative Gram-negative bacterial strain. Paper disc diffusion tests were conducted for the qualitative results, and a cell growth curve was drawn for quantitative results. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and IC<sub>50</sub> were measured from cell growth curves. As a result, all of the metal-CQDs showed toxicity against both Gram-positive and Gram-negative bacteria. Furthermore, Gram-negative bacteria was vulnerable to metal-CQDs than Gram-positive bacteria. The toxicity differed concerning the type of metal-CQDs; Mn-CQDs exhibited the highest efficacy. Hence, this study suggested that CQDs can be used as new nanoparticles for antibiotics.</p>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-29DOI: 10.1007/s42823-024-00782-6
Dong Hwan Kim, Eugene Oh, Sehyun Kim, Jaegeun Lee
The mass production of highly crystalline carbon nanotubes (CNTs) is highly demanded, yet achieving it remains challenging due to incomplete understanding of how synthetic parameters, except temperature, affect the crystallinity of CNTs. Notably, the choice of carbon precursor significantly influences CNT synthesis, but its impact on crystallinity remains unclear. Here, we employed a data analytics approach to examine the effect of carbon precursors on CNT crystallinity during their synthesis in a fluidized bed reactor. We compared ethylene, acetylene, and a mixture of these. Using Bayesian optimization (BO), we optimized synthesis conditions to maximize IG/ID of CNTs for each precursor. Key parameters considered were reaction temperature, precursor concentration, and hydrogen concentration. We conducted three separate BO processes to evaluate the effectiveness of each carbon precursor on CNT crystallinity. The results indicated no significant difference in IG/ID of CNTs among the carbon precursors. In addition, multiple linear regression analysis did not support a synergetic effect between acetylene and ethylene. Interestingly, contour plots demonstrated consistent relationships between synthesis parameters and IG/ID across different carbon precursors. This data analytics approach allowed us to successfully assess the impact of carbon precursors on the CNT crystallinity and analyze the relationship between synthesis parameters and CNT crystallinity.
{"title":"Data analytics approach to evaluating the impact of acetylene and ethylene precursors on the crystallinity of carbon nanotubes synthesized in a fluidized bed reactor","authors":"Dong Hwan Kim, Eugene Oh, Sehyun Kim, Jaegeun Lee","doi":"10.1007/s42823-024-00782-6","DOIUrl":"https://doi.org/10.1007/s42823-024-00782-6","url":null,"abstract":"<p>The mass production of highly crystalline carbon nanotubes (CNTs) is highly demanded, yet achieving it remains challenging due to incomplete understanding of how synthetic parameters, except temperature, affect the crystallinity of CNTs. Notably, the choice of carbon precursor significantly influences CNT synthesis, but its impact on crystallinity remains unclear. Here, we employed a data analytics approach to examine the effect of carbon precursors on CNT crystallinity during their synthesis in a fluidized bed reactor. We compared ethylene, acetylene, and a mixture of these. Using Bayesian optimization (BO), we optimized synthesis conditions to maximize <i>I</i><sub>G</sub>/<i>I</i><sub>D</sub> of CNTs for each precursor. Key parameters considered were reaction temperature, precursor concentration, and hydrogen concentration. We conducted three separate BO processes to evaluate the effectiveness of each carbon precursor on CNT crystallinity. The results indicated no significant difference in <i>I</i><sub>G</sub>/<i>I</i><sub>D</sub> of CNTs among the carbon precursors. In addition, multiple linear regression analysis did not support a synergetic effect between acetylene and ethylene. Interestingly, contour plots demonstrated consistent relationships between synthesis parameters and <i>I</i><sub>G</sub>/<i>I</i><sub>D</sub> across different carbon precursors. This data analytics approach allowed us to successfully assess the impact of carbon precursors on the CNT crystallinity and analyze the relationship between synthesis parameters and CNT crystallinity.</p>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-29DOI: 10.1007/s42823-024-00784-4
Guanru Chang, Lei Wang, Kunzhen Li, Chang Zhu, Hui Zhang, Min Guo
Supercapacitors, emerging as energy storage devices, face challenges in practical applications due to their relatively low energy density. In this study, we fabricate a novelty supercapacitor cathode composed of Co9S8, conductive phosphorus-doped carbon (P–C), and layered double hydroxides (LDH). The incorporation of a conductive layer significantly enhances charge transfer, capacity, and electrochemical stability, ultimately elevating the electrochemical performance of the cathode. The fabricated Co9S8@P–C@NiCo-LDH demonstrates an exceptional area-specific capacitance of 3.9 F cm−2 at a current density of 2 mA cm−2, along with remarkable cyclic stability, maintaining 98.9% of their capacity after 2000 cycles. The flexible asymmetric all-solid-state supercapacitor (AAS) assembled with Co9S8@P–C@NiCo-LDH and activated carbon (AC) exhibits a remarkable energy density of 0.065 mWh cm−2, corresponding to 325.0 W h kg−1. Moreover, it maintains excellent cycling stability even at elevated current densities of 10 mA cm−2. Following 5000 consecutive charge/discharge cycles, the AAS device maintains approximately 91.1% of its initial specific capacity. The AAS device successfully powered a 3V white LED for 5 min, further emphasizing its practicality.
超级电容器作为新兴的储能设备,由于能量密度相对较低,在实际应用中面临着挑战。在本研究中,我们制作了一种新型超级电容器阴极,由 Co9S8、导电掺磷碳(P-C)和层状双氢氧化物(LDH)组成。导电层的加入大大增强了电荷转移、容量和电化学稳定性,最终提升了阴极的电化学性能。制备的 Co9S8@P-C@NiCo-LDH 在电流密度为 2 mA cm-2 时的特定区域电容为 3.9 F cm-2,同时具有显著的循环稳定性,在 2000 次循环后仍能保持 98.9% 的容量。用 Co9S8@P-C@NiCo-LDH 和活性炭(AC)组装的柔性非对称全固态超级电容器(AAS)的能量密度高达 0.065 mWh cm-2,相当于 325.0 W h kg-1。此外,即使在 10 mA cm-2 的高电流密度下,它也能保持出色的循环稳定性。经过 5000 次连续充放电循环后,AAS 器件的比容量仍能保持在其初始比容量的 91.1% 左右。AAS 设备成功地为 3V 白色 LED 供电 5 分钟,进一步突出了其实用性。
{"title":"Preparation and performance study of flexible all-solid-state Co9S8@P–C @ NiCo-LDH / / AC asymmetric supercapacitors","authors":"Guanru Chang, Lei Wang, Kunzhen Li, Chang Zhu, Hui Zhang, Min Guo","doi":"10.1007/s42823-024-00784-4","DOIUrl":"https://doi.org/10.1007/s42823-024-00784-4","url":null,"abstract":"<p>Supercapacitors, emerging as energy storage devices, face challenges in practical applications due to their relatively low energy density. In this study, we fabricate a novelty supercapacitor cathode composed of Co<sub>9</sub>S<sub>8</sub>, conductive phosphorus-doped carbon (P–C), and layered double hydroxides (LDH). The incorporation of a conductive layer significantly enhances charge transfer, capacity, and electrochemical stability, ultimately elevating the electrochemical performance of the cathode. The fabricated Co<sub>9</sub>S<sub>8</sub>@P–C@NiCo-LDH demonstrates an exceptional area-specific capacitance of 3.9 F cm<sup>−2</sup> at a current density of 2 mA cm<sup>−2</sup>, along with remarkable cyclic stability, maintaining 98.9% of their capacity after 2000 cycles. The flexible asymmetric all-solid-state supercapacitor (AAS) assembled with Co<sub>9</sub>S<sub>8</sub>@P–C@NiCo-LDH and activated carbon (AC) exhibits a remarkable energy density of 0.065 mWh cm<sup>−2</sup>, corresponding to 325.0 W h kg<sup>−1</sup>. Moreover, it maintains excellent cycling stability even at elevated current densities of 10 mA cm<sup>−2</sup>. Following 5000 consecutive charge/discharge cycles, the AAS device maintains approximately 91.1% of its initial specific capacity. The AAS device successfully powered a 3V white LED for 5 min, further emphasizing its practicality.</p>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":null,"pages":null},"PeriodicalIF":4.5,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141868090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26DOI: 10.1007/s42823-024-00778-2
Tong Han, Ying-Ai Piao, Long-Yue Meng, Biao Jin
Food contamination with heavy-metal ions and nitrites poses a serious threat to human health. Consequently, the development of fast and sensitive platforms for detecting these contaminants is urgently needed. In this study, a novel sensing platform was developed by integrating carbon nanotubes generated by the pyrolysis of waste masks (WMCNTs) with ZIF-8 for the simultaneous detection of Cd2+, Pb2+, and nitrite. Specifically, the electronic structure of the WMCNT backbone was modulated by doping with B and N atoms. Nanoporous ZIF-8 was then grown in-situ on its surface to produce composites with enhanced electrical conductivities and large specific surface areas. This modification provided more active sites for the attachment of heavy-metal ions and nitrites. Under optimized conditions, the sensing platform exhibited a wide linear range with the Pb2+, Cd2+, and NO2− limits of detection of 2.68, 12.12, and 5.94 μM, respectively. Notably, the sensing platform demonstrated excellent anti-interference capabilities and effectively detected nitrites and heavy-metal ions in pickled foods.