Pub Date : 2025-12-08DOI: 10.1016/j.carbon.2025.121146
Jiajiang Zhou , Hengyu Hao , Bowen Yang , Yaqiong Su , Zhang Quan , Xinhua Qi , Feng Shen , Haixin Guo
The selective oxidation of glucose to value-added acids is pivotal for biomass valorization, yet achieving high activity and selectivity at room temperature with air as the sole oxidant remains challenging. Herein, PtZn alloy nanoparticles dispersed on surface-functionalized carbon nanotubes (CNTs) are developed for aerobic glucose oxidation under ambient conditions. The –COOH–enriched catalyst (PtZn/CNT-COOH) exhibits the highest performance, delivering a 94.5 % total-acid yield at 25 °C within 120 min in air, while hydroxyl-functionalized and unmodified supports show markedly lower efficiencies under identical conditions. The catalyst retains activity over repeated cycles, indicating robust stability. Comprehensive surface chemistry analyses verify the preservation and enrichment of –COOH groups, which enhance interfacial hydrophilicity and promote substrate capture. Complementary theoretical calculations indicate strengthened glucose adsorption and facilitated formyl C–H activation on PtZn/CNT-COOH relative to the other supports, accounting for its superior kinetics and selectivity. This work establishes a mild, air-breathing route to gluconic acid and provides a clear structure-function basis for designing COOH-directed supported catalysts for selective carbohydrate oxidations.
{"title":"PtZn alloy supported on functionalized carbon nanotubes for glucose oxidation at room temperature","authors":"Jiajiang Zhou , Hengyu Hao , Bowen Yang , Yaqiong Su , Zhang Quan , Xinhua Qi , Feng Shen , Haixin Guo","doi":"10.1016/j.carbon.2025.121146","DOIUrl":"10.1016/j.carbon.2025.121146","url":null,"abstract":"<div><div>The selective oxidation of glucose to value-added acids is pivotal for biomass valorization, yet achieving high activity and selectivity at room temperature with air as the sole oxidant remains challenging. Herein, PtZn alloy nanoparticles dispersed on surface-functionalized carbon nanotubes (CNTs) are developed for aerobic glucose oxidation under ambient conditions. The –COOH–enriched catalyst (PtZn/CNT-COOH) exhibits the highest performance, delivering a 94.5 % total-acid yield at 25 °C within 120 min in air, while hydroxyl-functionalized and unmodified supports show markedly lower efficiencies under identical conditions. The catalyst retains activity over repeated cycles, indicating robust stability. Comprehensive surface chemistry analyses verify the preservation and enrichment of –COOH groups, which enhance interfacial hydrophilicity and promote substrate capture. Complementary theoretical calculations indicate strengthened glucose adsorption and facilitated formyl C–H activation on PtZn/CNT-COOH relative to the other supports, accounting for its superior kinetics and selectivity. This work establishes a mild, air-breathing route to gluconic acid and provides a clear structure-function basis for designing COOH-directed supported catalysts for selective carbohydrate oxidations.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121146"},"PeriodicalIF":11.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-08DOI: 10.1016/j.carbon.2025.121144
Siyi Tong, Fen Wu, Xuge Niu, Jiahuan Xu, Jun Xiang
The development of lightweight high-performance microwave absorbers with multifunctional stealth capabilities is crucial for advancements in modern defense technologies. In this study, we present a novel hierarchical composite composed of N-doped carbon nanofibers (NCNFs) integrated with in situ-grown small Co3Fe7 nanoparticles (NPs) and short carbon nanotubes (CNTs), and we investigate the influence of the carbonization temperature on its electromagnetic and microwave absorption (MA) properties. The Co3Fe7@NCNFs/CNTs composites were synthesized through a facile electrospinning and subsequent carbonization process at different temperatures (800, 1000, and 1200 °C). The S1000 obtained at 1000 °C exhibits superior MA properties, with a minimum reflection loss (RL) of −72.2 dB at 1.62 mm and a maximum effective absorption bandwidth (EAB, RL < −10 dB) of 5.6 GHz (12.64–18.0 GHz) with a thickness of 1.35 mm. Further, S1000 has an ultra-low filler content of 5 wt%. This is attributed to the optimized impedance matching, the satisfactory dielectric and magnetic losses, and the synergistic effects of the hierarchical structure with zero-dimensional Co3Fe7 NPs, one-dimensional CNTs, and three-dimensional NCNFs conductive network. In addition, S1000 demonstrates excellent radar–infrared stealth performance, outstanding hydrophobicity (water contact angle of 153°), and significant corrosion/oxidation resistance in harsh environments. This work provides a promising strategy for designing lightweight, efficient, and durable MA materials that can be employed in radar–infrared compatible stealth applications.
{"title":"N-doped carbon nanofibers coupled with in situ-grown small Co3Fe7 nanoparticles and short carbon nanotubes for radar–infrared compatible stealth","authors":"Siyi Tong, Fen Wu, Xuge Niu, Jiahuan Xu, Jun Xiang","doi":"10.1016/j.carbon.2025.121144","DOIUrl":"10.1016/j.carbon.2025.121144","url":null,"abstract":"<div><div>The development of lightweight high-performance microwave absorbers with multifunctional stealth capabilities is crucial for advancements in modern defense technologies. In this study, we present a novel hierarchical composite composed of N-doped carbon nanofibers (NCNFs) integrated with in situ-grown small Co<sub>3</sub>Fe<sub>7</sub> nanoparticles (NPs) and short carbon nanotubes (CNTs), and we investigate the influence of the carbonization temperature on its electromagnetic and microwave absorption (MA) properties. The Co<sub>3</sub>Fe<sub>7</sub>@NCNFs/CNTs composites were synthesized through a facile electrospinning and subsequent carbonization process at different temperatures (800, 1000, and 1200 °C). The S1000 obtained at 1000 °C exhibits superior MA properties, with a minimum reflection loss (RL) of −72.2 dB at 1.62 mm and a maximum effective absorption bandwidth (EAB, RL < −10 dB) of 5.6 GHz (12.64–18.0 GHz) with a thickness of 1.35 mm. Further, S1000 has an ultra-low filler content of 5 wt%. This is attributed to the optimized impedance matching, the satisfactory dielectric and magnetic losses, and the synergistic effects of the hierarchical structure with zero-dimensional Co<sub>3</sub>Fe<sub>7</sub> NPs, one-dimensional CNTs, and three-dimensional NCNFs conductive network. In addition, S1000 demonstrates excellent radar–infrared stealth performance, outstanding hydrophobicity (water contact angle of 153°), and significant corrosion/oxidation resistance in harsh environments. This work provides a promising strategy for designing lightweight, efficient, and durable MA materials that can be employed in radar–infrared compatible stealth applications.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121144"},"PeriodicalIF":11.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-08DOI: 10.1016/j.carbon.2025.121141
Sławomir Dyjak , Mateusz Gratzke , Iwona Wyrębska , Artur Błachowski , Youn-Bae Kang , Kamil Sobczak , Waldemar Kaszuwara , Wojciech Kiciński
Non-graphitizable carbonaceous materials containing iron and sulfur are subjected to pyrolysis at 1150, 1300, and 1450 °C under a dynamic vacuum. Three batches of samples are prepared with initial iron-to-sulfur molar ratios (in the starting mixture of reagents) of 1, 10, and 100. After the vacuum pyrolysis, iron-based phases are removed from the resulting carbon materials by high-temperature heat treatment with Cl2, followed by H2. This research examines how the initial sulfur content in the carbon-rich carbon-iron-sulfur (C–Fe–S) ternary system influences the graphitization process within a moderate temperature range, particularly focusing on the effectiveness of the catalytic graphitization. A key observation is that the system with the highest sulfur content exhibits the greatest extent of graphitization. In contrast, the system with the lowest sulfur content shows the poorest conversion yield to the partly graphitized carbon phase. This study provides evidence and elucidates why sulfur-rich C–Fe–S mixtures produce greater amounts of graphitized phases than S-deficient mixtures, irrespective of the vacuum pyrolysis temperature.
{"title":"Carbon-iron-sulfur ternary system under elevated temperature and reduced pressure: implications for the catalytic graphitization phenomenon","authors":"Sławomir Dyjak , Mateusz Gratzke , Iwona Wyrębska , Artur Błachowski , Youn-Bae Kang , Kamil Sobczak , Waldemar Kaszuwara , Wojciech Kiciński","doi":"10.1016/j.carbon.2025.121141","DOIUrl":"10.1016/j.carbon.2025.121141","url":null,"abstract":"<div><div>Non-graphitizable carbonaceous materials containing iron and sulfur are subjected to pyrolysis at 1150, 1300, and 1450 °C under a dynamic vacuum. Three batches of samples are prepared with initial iron-to-sulfur molar ratios (in the starting mixture of reagents) of 1, 10, and 100. After the vacuum pyrolysis, iron-based phases are removed from the resulting carbon materials by high-temperature heat treatment with Cl<sub>2</sub>, followed by H<sub>2</sub>. This research examines how the initial sulfur content in the carbon-rich carbon-iron-sulfur (C–Fe–S) ternary system influences the graphitization process within a moderate temperature range, particularly focusing on the effectiveness of the catalytic graphitization. A key observation is that the system with the highest sulfur content exhibits the greatest extent of graphitization. In contrast, the system with the lowest sulfur content shows the poorest conversion yield to the partly graphitized carbon phase. This study provides evidence and elucidates why sulfur-rich C–Fe–S mixtures produce greater amounts of graphitized phases than S-deficient mixtures, irrespective of the vacuum pyrolysis temperature.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121141"},"PeriodicalIF":11.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-08DOI: 10.1016/j.carbon.2025.121143
Jixi Zhou , Xinmeng Huang , Di Lan , Zirui Jia , Guanglei Wu
Reasonable component design and controllable structure are the effective strategies to realize the electromagnetic properties of composite materials. Meanwhile It is an effective strategy to improve vanadium-based composite materials by rational structural design and component optimization. The carbon nanocage structure with 3D interlocking pore structure was prepared by electrospinning technology. Meanwhile, ammonium metavanadate and cobalt nitrate are used as vanadium sources and annealed in an ammoniac-free environment to achieve partial nitridation of vanadium, forming a VN/V2O3 heterostructure and increasing the interfacial polarization effect of the material. And cobalt ions form cobalt particles under the action of high temperature reduction. Cobalt particles Anchor the porous carbon nanocages, making up for the deficiency of magnetic loss of the composite material. In this research, both interface control and structural design are realized, and excellent magnetic loss performance is provided for the material. This research also maintain excellent stability in simulated seawater, and enhance corrosion resistance. Therefore, this sample has the dual functions of corrosion resistance and microwave absorption. When the thickness is 2.8 mm, the minimum reflection loss reaches −56.35 dB; When the thickness is 2.2 mm, the effective absorption bandwidth reaches 7.44 GHz.
{"title":"Multi-interface polarization engineering constructs one-dimensional carbon nanocages heterostructures for efficient electromagnetic wave absorption","authors":"Jixi Zhou , Xinmeng Huang , Di Lan , Zirui Jia , Guanglei Wu","doi":"10.1016/j.carbon.2025.121143","DOIUrl":"10.1016/j.carbon.2025.121143","url":null,"abstract":"<div><div>Reasonable component design and controllable structure are the effective strategies to realize the electromagnetic properties of composite materials. Meanwhile It is an effective strategy to improve vanadium-based composite materials by rational structural design and component optimization. The carbon nanocage structure with 3D interlocking pore structure was prepared by electrospinning technology. Meanwhile, ammonium metavanadate and cobalt nitrate are used as vanadium sources and annealed in an ammoniac-free environment to achieve partial nitridation of vanadium, forming a VN/V<sub>2</sub>O<sub>3</sub> heterostructure and increasing the interfacial polarization effect of the material. And cobalt ions form cobalt particles under the action of high temperature reduction. Cobalt particles Anchor the porous carbon nanocages, making up for the deficiency of magnetic loss of the composite material. In this research, both interface control and structural design are realized, and excellent magnetic loss performance is provided for the material. This research also maintain excellent stability in simulated seawater, and enhance corrosion resistance. Therefore, this sample has the dual functions of corrosion resistance and microwave absorption. When the thickness is 2.8 mm, the minimum reflection loss reaches −56.35 dB; When the thickness is 2.2 mm, the effective absorption bandwidth reaches 7.44 GHz.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121143"},"PeriodicalIF":11.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-08DOI: 10.1016/j.carbon.2025.121147
Shunsuke Hasumi, Tomonori Ohba
Membrane separation has emerged as a promising and environmentally friendly technique providing high selectivity and permeability. Graphene could be an extremely highly permeable gas separation membrane; however, its implementation and separation ability require further improvement. Herein, we describe the optimization of a graphene membrane for CO2/CH4 gas separation using molecular dynamics (MD) simulations. The MD simulations indicate that among the evaluated membranes, only that with pores of 0.41 nm in diameter exhibits sufficient separation ability. However, as the graphene pore size and distribution are experimentally difficult to control, we need to investigate the other controllable parameter, except for the graphene pore size. The experimental separation test indicates that graphene membranes achieve a CO2/CH4 selectivity greater than one without strict control of the pore size. We assume that the high selectivity is due to the oxygen-functional groups on graphene. MD simulations performed for the graphene with oxygen functional groups then indicate that oxygen functionalization enhances the separation and permeance abilities of graphene. Subsequently, partial oxidation of graphene by O2 plasma treatment is also experimentally demonstrated to increase the CO2/CH4 selectivity of the graphene membrane while maintaining the CO2 permeance. Therefore, this study demonstrates that oxygen functionalization enhances the separation performance of graphene-based membranes.
{"title":"Enhancing the CO2/CH4 gas separation performance of graphene membranes via oxygen functionalization","authors":"Shunsuke Hasumi, Tomonori Ohba","doi":"10.1016/j.carbon.2025.121147","DOIUrl":"10.1016/j.carbon.2025.121147","url":null,"abstract":"<div><div>Membrane separation has emerged as a promising and environmentally friendly technique providing high selectivity and permeability. Graphene could be an extremely highly permeable gas separation membrane; however, its implementation and separation ability require further improvement. Herein, we describe the optimization of a graphene membrane for CO<sub>2</sub>/CH<sub>4</sub> gas separation using molecular dynamics (MD) simulations. The MD simulations indicate that among the evaluated membranes, only that with pores of 0.41 nm in diameter exhibits sufficient separation ability. However, as the graphene pore size and distribution are experimentally difficult to control, we need to investigate the other controllable parameter, except for the graphene pore size. The experimental separation test indicates that graphene membranes achieve a CO<sub>2</sub>/CH<sub>4</sub> selectivity greater than one without strict control of the pore size. We assume that the high selectivity is due to the oxygen-functional groups on graphene. MD simulations performed for the graphene with oxygen functional groups then indicate that oxygen functionalization enhances the separation and permeance abilities of graphene. Subsequently, partial oxidation of graphene by O<sub>2</sub> plasma treatment is also experimentally demonstrated to increase the CO<sub>2</sub>/CH<sub>4</sub> selectivity of the graphene membrane while maintaining the CO<sub>2</sub> permeance. Therefore, this study demonstrates that oxygen functionalization enhances the separation performance of graphene-based membranes.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121147"},"PeriodicalIF":11.6,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-07DOI: 10.1016/j.carbon.2025.121142
Yuanming Yang , Liwei Wen , Yi Yan , Jiaqi Tao , Yijie Liu , Kunpeng Li , Kexin Zou , Jintao Long , Zhengjun Yao , Jintang Zhou
The synergistic design of nanomaterials' composition and structure has become a key pathway for enhance microwave absorption (MA). However, achieving precise control between material design and MA properties remains a formidable challenge. In this study, we propose a hierarchical synthesis strategy integrating dual-shell spatial confinement and sequential templating. By regulating the chemical reaction kinetics during ion exchange and the thermodynamic behavior in subsequent annealing processes, which facilitates structural evolution and cumulative performance enhancement to MA. It is demonstrated that the fabricated 0.5CN/C-700 sample exhibits outstanding impedance matching characteristics and attenuation capabilities. In particular, the COMSOL simulations reveal that alloy particles significantly enhance the material's electromagnetic response by intensifying its local electric fields and power loss. Combined with ingenious interface-defects engineering, it achieves an effective absorption bandwidth (EAB) of 6.47 GHz with a maximum absorption efficiency of 99.9999 %. Overall, the work not only provides a new paradigm for the rational design of high-performance microwave absorption materials (MAM), but also offers deepened insights into the tailoring of electromagnetic properties through kinetic and thermodynamic control in chemical synthesis.
{"title":"Space-confined ion exchange construction of tailored CoNi/double-shell carbon towards efficient microwave absorption","authors":"Yuanming Yang , Liwei Wen , Yi Yan , Jiaqi Tao , Yijie Liu , Kunpeng Li , Kexin Zou , Jintao Long , Zhengjun Yao , Jintang Zhou","doi":"10.1016/j.carbon.2025.121142","DOIUrl":"10.1016/j.carbon.2025.121142","url":null,"abstract":"<div><div>The synergistic design of nanomaterials' composition and structure has become a key pathway for enhance microwave absorption (MA). However, achieving precise control between material design and MA properties remains a formidable challenge. In this study, we propose a hierarchical synthesis strategy integrating dual-shell spatial confinement and sequential templating. By regulating the chemical reaction kinetics during ion exchange and the thermodynamic behavior in subsequent annealing processes, which facilitates structural evolution and cumulative performance enhancement to MA. It is demonstrated that the fabricated 0.5CN/C-700 sample exhibits outstanding impedance matching characteristics and attenuation capabilities. In particular, the COMSOL simulations reveal that alloy particles significantly enhance the material's electromagnetic response by intensifying its local electric fields and power loss. Combined with ingenious interface-defects engineering, it achieves an effective absorption bandwidth (EAB) of 6.47 GHz with a maximum absorption efficiency of 99.9999 %. Overall, the work not only provides a new paradigm for the rational design of high-performance microwave absorption materials (MAM), but also offers deepened insights into the tailoring of electromagnetic properties through kinetic and thermodynamic control in chemical synthesis.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121142"},"PeriodicalIF":11.6,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-06DOI: 10.1016/j.carbon.2025.121140
Junzhu Yang , Junchen Liu , Yi Zhang , Wei Pei , Qi Xia , Sanyang Han , Yuan Lu
Efficient regeneration of the coenzymes NADH and NADPH is crucial for sustaining biocatalytic processes, particularly in driving the biocatalysis reaction. In this study, the photocatalytic properties of alkali-doped graphitic carbon nitrates were explored to achieve efficient NAD(P)H regeneration. g-C3N4 doped with potassium (KOH), sodium (NaOH), and calcium (Ca(OH)2) was synthesized and characterized, showing significant enhancements in light absorption, charge separation, and photogenerated electron transport. Among the synthesized photocatalysts, KOH-doped g-C3N4 (KCN) exhibited the best photocatalytic performance, regenerating 95 % NADH and 92 % NADPH within 30 min. This result compares favorably with those reported in previous studies. Based on this superior performance, K-0.2 was further applied to the in vitro CO2 reduction to formate as a proof of concept. To clarify the mechanistic insights of the improved photocatalytic performance of KCN, the chemical model of g-C3N4 and KCN was established, and DFT calculations were performed to reveal the electronic structure modifications responsible for the enhanced photocatalytic activity. Furthermore, to expand the light utilization capability of the system, upconversion nanoparticles (UCNPs) were incorporated into the system to utilize near-infrared light (980 nm), which successfully achieved NADH regeneration under near-infrared excitation and extended the light absorption range of the photocatalytic system. Overall, this study demonstrated that alkali-doped g-C3N4 offered a highly efficient platform for NAD(P)H regeneration, and the integration of UCNPs further enriched the coenzyme regeneration scenario, suggesting a promising strategy for advancing sustainable coenzyme regeneration technologies.
{"title":"Photocatalytic NAD(P)H regeneration by alkali-doped g-C3N4 and extending visible light to near-infrared light","authors":"Junzhu Yang , Junchen Liu , Yi Zhang , Wei Pei , Qi Xia , Sanyang Han , Yuan Lu","doi":"10.1016/j.carbon.2025.121140","DOIUrl":"10.1016/j.carbon.2025.121140","url":null,"abstract":"<div><div>Efficient regeneration of the coenzymes NADH and NADPH is crucial for sustaining biocatalytic processes, particularly in driving the biocatalysis reaction. In this study, the photocatalytic properties of alkali-doped graphitic carbon nitrates were explored to achieve efficient NAD(P)H regeneration. g-C<sub>3</sub>N<sub>4</sub> doped with potassium (KOH), sodium (NaOH), and calcium (Ca(OH)<sub>2</sub>) was synthesized and characterized, showing significant enhancements in light absorption, charge separation, and photogenerated electron transport. Among the synthesized photocatalysts, KOH-doped g-C<sub>3</sub>N<sub>4</sub> (KCN) exhibited the best photocatalytic performance, regenerating 95 % NADH and 92 % NADPH within 30 min. This result compares favorably with those reported in previous studies. Based on this superior performance, K-0.2 was further applied to the <em>in vitro</em> CO<sub>2</sub> reduction to formate as a proof of concept. To clarify the mechanistic insights of the improved photocatalytic performance of KCN, the chemical model of g-C<sub>3</sub>N<sub>4</sub> and KCN was established, and DFT calculations were performed to reveal the electronic structure modifications responsible for the enhanced photocatalytic activity. Furthermore, to expand the light utilization capability of the system, upconversion nanoparticles (UCNPs) were incorporated into the system to utilize near-infrared light (980 nm), which successfully achieved NADH regeneration under near-infrared excitation and extended the light absorption range of the photocatalytic system. Overall, this study demonstrated that alkali-doped g-C<sub>3</sub>N<sub>4</sub> offered a highly efficient platform for NAD(P)H regeneration, and the integration of UCNPs further enriched the coenzyme regeneration scenario, suggesting a promising strategy for advancing sustainable coenzyme regeneration technologies.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121140"},"PeriodicalIF":11.6,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-05DOI: 10.1016/S0008-6223(25)01134-0
{"title":"Outside Front Cover - Journal name, Cover image, Volume issue details, ISSN, Cover Date, Elsevier Logo and Society Logo if required","authors":"","doi":"10.1016/S0008-6223(25)01134-0","DOIUrl":"10.1016/S0008-6223(25)01134-0","url":null,"abstract":"","PeriodicalId":262,"journal":{"name":"Carbon","volume":"247 ","pages":"Article 121118"},"PeriodicalIF":11.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-05DOI: 10.1016/j.carbon.2025.121138
Hassan A. Almousa , Hugo G. De Luca , David B. Anthony , Emile S. Greenhalgh , Alexander Bismarck , Milo S.P. Shaffer
Carbon nanotube (CNT) grafted carbon fibers (CFs) are promising for multifunctional composites (CFRPs) but remain limited by scalability, non-uniform growth, and degradation of fiber tensile strength. This paper reports a continuous spool-to-spool chemical vapor deposition (CVD) process that achieves uniform CNT growth throughout 12k CF tows while preserving fiber tensile properties. The uniformity of CNT coverage, over meters of length and across thousands of fibers, was objectively established via a multi-length scale characterization protocol, combining machine learning-based SEM classification with macroscopic measurements of BET-based specific surface area (SSA) and gravimetric CNT content. Microscopic and macroscopic measurements are independently self-consistent. To understand and optimize CNT growth, a new dynamic snapshot method was developed and combined with steady-state computational fluid dynamics (CFD) modelling to resolve the spatial evolution of catalyst activation, nucleation, and CNT growth kinetics as a function of reactor temperature and species concentrations. These insights informed targeted modifications to gas flow and temperature conditions, enabling reproducible CNT growth at 550 °C. Under optimized CVD conditions, the CFs were grafted with a CNT corona of 850 nm in length, corresponding to a loading of 2.9 wt% on the fibers, which led to a ten-fold increase in SSA (5.35 m2 g−1). The process was shown to be stable for extended lengths (>50 m) and reproducible across multiple runs, establishing a scalable route for integrating CNT-grafted CFs into conventional manufacturing. This experimental-computational framework provides a rational approach toward high-performance multifunctional, hierarchical CFRPs.
{"title":"Uniform and scalable carbon nanotube growth on carbon fibers: Insights from experimental dynamic snapshots and computational fluid dynamics","authors":"Hassan A. Almousa , Hugo G. De Luca , David B. Anthony , Emile S. Greenhalgh , Alexander Bismarck , Milo S.P. Shaffer","doi":"10.1016/j.carbon.2025.121138","DOIUrl":"10.1016/j.carbon.2025.121138","url":null,"abstract":"<div><div>Carbon nanotube (CNT) grafted carbon fibers (CFs) are promising for multifunctional composites (CFRPs) but remain limited by scalability, non-uniform growth, and degradation of fiber tensile strength. This paper reports a continuous spool-to-spool chemical vapor deposition (CVD) process that achieves uniform CNT growth throughout 12k CF tows while preserving fiber tensile properties. The uniformity of CNT coverage, over meters of length and across thousands of fibers, was objectively established via a multi-length scale characterization protocol, combining machine learning-based SEM classification with macroscopic measurements of BET-based specific surface area (SSA) and gravimetric CNT content. Microscopic and macroscopic measurements are independently self-consistent. To understand and optimize CNT growth, a new dynamic snapshot method was developed and combined with steady-state computational fluid dynamics (CFD) modelling to resolve the spatial evolution of catalyst activation, nucleation, and CNT growth kinetics as a function of reactor temperature and species concentrations. These insights informed targeted modifications to gas flow and temperature conditions, enabling reproducible CNT growth at 550 °C. Under optimized CVD conditions, the CFs were grafted with a CNT corona of 850 nm in length, corresponding to a loading of 2.9 wt% on the fibers, which led to a ten-fold increase in SSA (5.35 m<sup>2</sup> g<sup>−1</sup>). The process was shown to be stable for extended lengths (>50 m) and reproducible across multiple runs, establishing a scalable route for integrating CNT-grafted CFs into conventional manufacturing. This experimental-computational framework provides a rational approach toward high-performance multifunctional, hierarchical CFRPs.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":"248 ","pages":"Article 121138"},"PeriodicalIF":11.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-05DOI: 10.1016/j.carbon.2025.121113
Benjamin M. Ringel, Henry J. Boesch, Sreevishnu Oruganti, Laura Villafañe, Francesco Panerai
Mechanical erosion of ablative heat shield materials, known as spallation, was investigated in supersonic air and nitrogen plasmas produced by an inductively coupled plasma wind tunnel at aerothermal conditions representative of atmospheric entry. Spalled particles from low-density carbon ablators were tracked using high-speed imaging, enabling time-resolved analysis of spallation events. Tests in nitrogen revealed high temporal variance in particle production over time, while tests in air exhibited steady particle release. Post-test microscopy and spectroscopy identified a disordered nitrogen-functionalized carbon precipitate that forms exclusively in nitrogen plasma. Under extreme conditions, this deposit decreases surface permeability, enabling subsurface pressure buildup that drives unsteady particle release. Spalled particle size was inferred from velocity data obtained via particle tracking, enabling estimation of spallation mass loss. Spallation was estimated to account for upwards of 45% of total mass loss for tests in nitrogen, underscoring its significance in anaerobic entry conditions. Results suggest that deposit formation, material orientation, and environment conditions collectively govern spallation behavior.
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