Carbon Letters最新文献

{"title":"Synergetic solvent extraction and ionic liquid engineering for one-step carbonization of coal tar pitch toward sodium-ion anodes","authors":"Rong Wang,&nbsp;Zhenjie Dai,&nbsp;Ishioma Laurene Egun,&nbsp;Haiyang Yu,&nbsp;Guoliang Ling,&nbsp;Yichao Wang,&nbsp;Zhengfei Chen","doi":"10.1007/s42823-026-01101-x","DOIUrl":"10.1007/s42823-026-01101-x","url":null,"abstract":"<div><p>Sodium-ion batteries (SIBs) have emerged as a promising complement to lithium-ion batteries due to the natural abundance and low cost of sodium resources. However, the large ionic radius and sluggish kinetics of Na⁺ lead to slow diffusion and inferior electrochemical performance of conventional anode materials. Herein, we report a facile and sustainable strategy for the upcycling of coal tar pitch (CTP) into functional carbon anodes. N-Methyl-2-pyrrolidone (NMP) was first employed for solvent extraction of CTP, followed by incorporation of imidazolium-based ionic liquids, 1-butyl-3-methylimidazolium bromide ([BMIM]Br) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF₆). A single-step carbonization process enabled in situ heteroatom doping and structural regulation of the derived carbons. Systematic structural characterization and electrochemical evaluation reveal that CTP-NMP-[BMIM]Br possesses the highest nitrogen content (4.36 at%), delivers an initial coulombic efficiency of 55.43%, and exhibits excellent cycling stability with a reversible capacity of 153.2 mAh g^− 1 after 500 cycles at 50 mA g^− 1. This better electrochemical performance is attributed to its larger interlayer spacing, better hierarchical pore structure, large pore volume and defect sites that promote better sodium ion storage and transport characteristics. This work presents a green and scalable approach for transforming coal tar pitch into high-value carbon materials and highlights the role of ionic liquids as effective modifiers for tailoring microstructure, heteroatom chemistry, and porosity, thereby enabling high-performance carbon anodes for SIBs.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1911 - 1925"},"PeriodicalIF":6.2,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459053","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}

{"title":"The mesopore development of the activated carbon from coconut husk via flow-through fractionation and superheated steam activation for dye and metal adsorption","authors":"Minh Duc Vu,&nbsp;Imam Hidayat Nurwahid,&nbsp;Minh Tuan Pham,&nbsp;Duc Loi Vu,&nbsp;Sarah Keiza Ismail,&nbsp;Viet Anh Hoang,&nbsp;Chang Soo Kim","doi":"10.1007/s42823-026-01096-5","DOIUrl":"10.1007/s42823-026-01096-5","url":null,"abstract":"<div><p>This study presents a sustainable biorefinery strategy for producing high-performance activated carbon from coconut husk by integrating flow-through fractionation with superheated steam (SHS) activation. Organosolv pretreatment with 50 vol% ethanol selectively removed lignin (68.2%) and hemicellulose, enabling hierarchical pore development. The resulting ethanol-fractionated, SHS-activated carbon (SCHF(EtOH)) exhibited a highly porous structure with a BET surface area of 698.9 m²/g and a total pore volume of 0.443 cm³/g, outperforming commercial activated carbon and water-pretreated samples. Batch adsorption tests showed that SCHF(EtOH) achieved superior uptake capacities for organic dyes (104.8 mg/g for methylene blue, 83.6 mg/g for rhodamine B, and 45.0 mg/g for new coccine) and heavy metal ions (7.4 mg/g for Ni(II) and 16.1 mg/g for Cu(II)). This performance is attributed to the synergistic effects of a well-developed mesoporous network that enhances molecular diffusion and abundant oxygen-containing functional groups that provide active binding sites. Beyond producing advanced activated carbon, the integrated process also recovers high-quality lignin and hemicellulose, reducing the direct volatilization into greenhouse gas byproducts during activation by up to 62.7%. Overall, this work demonstrates a viable pathway for converting agricultural residues into value-added materials for advanced water purification.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1853 - 1867"},"PeriodicalIF":6.2,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459049","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}

{"title":"When is graphite better than graphene? a device-level comparison of batteries and water treatment","authors":"Mohd Hazarel Zairy Mohd Harun,&nbsp;Wan Aisyah Fadilah Wae AbdulKadir,&nbsp;Mohd Asyadi Azam,&nbsp;Imran Riaz","doi":"10.1007/s42823-026-01094-7","DOIUrl":"10.1007/s42823-026-01094-7","url":null,"abstract":"<div><p>This review critically compares graphite and graphene as electrode materials for batteries and electrochemical water and wastewater treatment, with emphasis on when graphite offers the more practical choice despite graphene’s superior intrinsic properties. Graphene-based materials, including pristine/few-layer graphene, graphene oxide (GO), reduced GO (rGO) and related composites, provide high electrical conductivity, large theoretical surface area, abundant active sites, and strong potential for defect engineering, although these properties vary strongly with derivative type, defect density, functionalization, and synthesis route [1]. However, the literature shows that these advantages are often limited by restacking, structural fragility, interfacial instability, scale-up difficulty, and high production cost. In contrast, graphite remains highly competitive because it combines adequate conductivity, mechanical robustness, corrosion resistance, manufacturing maturity, and lower cost. In battery applications, graphite continues to dominate commercial anodes owing to its reliable intercalation chemistry, favorable first-cycle efficiency, electrode density, process compatibility, and emerging recyclability, whereas graphene is more effective as a conductive scaffold or composite enhancer than as a direct replacement. In electrochemical water treatment, graphite-based electrodes and graphite felt frequently outperform graphene when long-term durability, self-supporting structure, regenerability, and operation under realistic flow conditions are required. Conversely, graphene remains difficult to replace in flexible, wearable, transparent, and conformal electrode architectures, where its atomically thin and mechanically adaptable structure enables device formats that graphite cannot easily provide [2]. Overall, the evidence indicates that graphite is often the better device-level solution when durability, scalability, and economic viability matter more than maximum nanoscale performance alone.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1447 - 1474"},"PeriodicalIF":6.2,"publicationDate":"2026-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459051","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}

{"title":"Influence of mesophase domain orientation on graphite crystallinity under constant mesophase content","authors":"Hye In Son,&nbsp;Ki Bong Lee,&nbsp;Ha Eun Yu,&nbsp;Sang Wan Seo,&nbsp;Soo Hong Lee,&nbsp;Ji Sun Im","doi":"10.1007/s42823-026-01097-4","DOIUrl":"10.1007/s42823-026-01097-4","url":null,"abstract":"<div><p>Petroleum graphite derived from petroleum residue is typically produced through the heat treatment of primary products such as coke or pitch. The mesophase structure formed at this stage governs crystal growth during graphitization and strongly influences the electrochemical behavior of graphite. However, the mesophase content and orientation do not necessarily evolve proportionally, making it difficult to isolate the intrinsic effect of domain orientation on graphite crystallinity and electrochemical performance. In this study, we report the effects of mesophase domain orientation on graphite crystallinity and the electrochemical performance of lithium-ion batteries while maintaining a constant mesophase content. The mesophase content is maintained at 94 wt% to isolate the effect of mesophase domain morphology. The synthesis conditions of the primary product were determined based on a first-order reaction-kinetic model and the Arrhenius relationship, enabling consistent mesophase content across different synthesis temperatures. The mesophase orientation parameter varies from 8.22 to 45.37 depending on the synthesis temperature, as confirmed by histogram analysis. Samples with controlled domain alignment retained their mesophase-derived structural characteristics even after graphitization. Notably, the mesophase orientation induced an inverse relationship between d₀₀₂ spacing and crystallinity, indicating that the structural characteristics of graphite after graphitization can be tuned by controlling the mesophase domain orientation. More importantly, the capacity retention at 5 C, relative to that at 0.2 C, increases from 66.9% to 88.6% by controlling the mesophase domain orientation. These results highlight that decoupling the mesophase orientation from mesophase content provides a practical strategy for tailoring the graphite structure and producing graphite materials favorable for high-rate charge–discharge applications.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1869 - 1882"},"PeriodicalIF":6.2,"publicationDate":"2026-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148458711","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}

{"title":"Synthesis of homogeneously dispersed ZnS on nanocarbons as anode materials for lithium-ion batteries","authors":"Hosung Hwang,&nbsp;Daehyeon Seo,&nbsp;Wonbin Nam,&nbsp;Jaewon Choi,&nbsp;Sungho Lee,&nbsp;Se Youn Cho","doi":"10.1007/s42823-026-01103-9","DOIUrl":"10.1007/s42823-026-01103-9","url":null,"abstract":"<div><p>Transition-metal chalcogenides such as zinc sulfide (ZnS) have garnered significant attention as promising materials for various primary and secondary batteries. However, ZnS suffers from inherent drawbacks, including low electrical conductivity and structural instability induced by volume expansion during cycling for ZnS anode. To overcome these limitations, the combination of ZnS with carbon-based materials offers a promising alternative to graphite anodes in lithium-ion batteries. In this study, ZnS nanoparticles were incorporated into a carbon-carbon composite consisting of nanocarbons (NCs) and CNTs. Metal-organic frameworks containing Zn were synthesized on the surface of CNTs and subsequently carbonized to derive the NCs, exhibiting uniformly dispersed Zn, offering additional active sites for anchoring sulfur to form ZnS nanoparticles. Moreover, the incorporation of CNTs into the ZnS@NC composite substantially enhanced electrical conductivity, resulting in a specific capacity exceeding 800 mAh g⁻¹ at a current density of 0.1 A g⁻¹. Cycling tests further demonstrated that ZnS@NC/CNT retained a stable capacity of 802.3 mAh g⁻¹ at 0.5 A g⁻¹ after 400 cycles, highlighting its remarkable stability and high discharge capacity. These findings highlight the synergistic contributions of ZIF-8-derived NCs and CNTs in improving electrochemical performance, establishing the composite as a promising candidate for next-generation energy storage systems.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1943 - 1953"},"PeriodicalIF":6.2,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459032","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}

{"title":"Controlled pore structure and surface properties of petroleum pitch-based mesoporous carbon prepared using silica as a template","authors":"Jae Jun Lee,&nbsp;Young Chul Choi","doi":"10.1007/s42823-026-01093-8","DOIUrl":"10.1007/s42823-026-01093-8","url":null,"abstract":"<div><p>Petroleum pitch-based mesoporous carbons were synthesized using a colloidal silica templating method, and the effects of imprinting temperature, pitch-to-silica ratio, and H₂O₂ oxidative pretreatment on pore development and surface chemistry were systematically investigated. The imprinting process facilitated the infiltration and dispersion of silica particles within the softened pitch matrix, leading to the formation of interconnected mesoporous structures after carbonization and silica removal. The mesoporous carbons exhibited typical type-IV N₂ adsorption–desorption isotherms with H2-type hysteresis loops, indicating the presence of interconnected mesopores. Among the investigated conditions, the sample prepared at an imprinting temperature of 350 °C with a pitch-to-silica ratio of 1:2.4 showed the most developed mesoporous structure, exhibiting a specific surface area of 342 m² g⁻¹ and a total pore volume of 1.11 cm³ g⁻¹. H₂O₂ oxidative pretreatment introduced oxygen-containing functional groups onto the pitch surface, improving the interaction between pitch and hydrophilic silica particles. Moderate oxidation for 2 h further enhanced the specific surface area to 446 m² g⁻¹ and increased pore accessibility while maintaining structural stability. However, excessive oxidation caused structural degradation and reduced pore uniformity. XRD analysis revealed that all samples possessed low graphitic ordering characteristic of template-assisted mesoporous carbons, while XPS and FTIR analyses confirmed the introduction and partial retention of oxygen-containing functional groups after carbonization. The resulting mesoporous carbons exhibited high mesopore fractions exceeding 90% and pore sizes in the range of 15–25 nm, suggesting their structural suitability as catalyst supports for proton exchange membrane fuel cells (PEMFCs).</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1825 - 1838"},"PeriodicalIF":6.2,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459033","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}

{"title":"Platinum-decorated biochar from pequi tree bark as a sustainable catalyst for hydrogen production from ammonia borane","authors":"Antonio Machado Netto,&nbsp;Mariele Dalmolin da Silva,&nbsp;Marcela de Oliveira Brahim Cortez,&nbsp;Gessica do Carmo Dias,&nbsp;Bárbara Fernandes de Souza,&nbsp;Guilherme Mateus Bousada,&nbsp;Renata Pereira Lopes Moreira","doi":"10.1007/s42823-026-01084-9","DOIUrl":"10.1007/s42823-026-01084-9","url":null,"abstract":"<div><p>Global efforts to mitigate environmental impacts have intensified the demand for cleaner and more sustainable energy systems. Thus, the development of highly efficient and environmentally benign catalysts for hydrogen (H₂) production has emerged as a promising strategy. In this work, a high-performance nanocatalyst composed of platinum nanoparticles supported on activated biochar (Pt NPs/AcB) was developed for hydrogen generation via NH₃BH₃ hydrolysis. The catalytic support was obtained through the valorization of pequi (<i>Caryocar brasiliense</i>) peel, an abundant agricultural residue, using pyrolysis followed by chemical activation with ZnCl₂. The activation process yielded a material with remarkable textural properties, including a high specific surface area of 1142.43 m² g⁻¹ and a predominantly mesoporous structure, which is highly favorable for metal nanoparticle dispersion and anchoring. The Pt NPs/AB catalyst exhibited outstanding catalytic activity toward NH₃BH₃ hydrolysis, achieving a hydrogen generation rate (HGR) of 2982.1 mL min⁻¹ g⁻¹ under optimized conditions (6.5 mmol% Pt, 10 mg of support, 1.00 mL of NH₃BH₃ solution at 0.648 mol L⁻¹, and 30 °C). Mechanistic investigations revealed a primary kinetic isotope effect (KIE) of 6.74, indicating that cleavage of the O–H bond of water is the rate-determining step of the reaction. In addition, the catalyst demonstrated excellent durability, maintaining approximately 100% efficiency over 30 consecutive reaction cycles. Overall, this work presents a robust and sustainable catalytic system that provides an efficient route for on-demand hydrogen generation while highlighting the potential of residual biomass as a precursor for advanced carbon materials in energy-related applications.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1695 - 1710"},"PeriodicalIF":6.2,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s42823-026-01084-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148458894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electroactive 3D-printed monolithic PAC filters for integrated adsorption and electrochemical oxidation of dyes","authors":"Da-Yeon Kim,&nbsp;Hyemin Kim,&nbsp;Eun-Hee Lee,&nbsp;Seung-Woo Lee","doi":"10.1007/s42823-026-01073-y","DOIUrl":"10.1007/s42823-026-01073-y","url":null,"abstract":"<div><p>Powdered activated carbon (PAC) is widely used for dye removal because of its high adsorption capacity and large specific surface area; however, its practical application is severely limited by poor handleability, difficult recovery, and low regenerability. Here, we report a three-dimensional (3D)-printed PAC-based monolithic filter that structurally and functionally integrates adsorption and electrochemical advanced oxidation within a single carbon architecture. The monolithic filters were fabricated by direct ink writing (DIW) of a carbon-rich ink containing PAC and polymeric binders, followed by solvent-exchange-induced phase inversion to generate a mechanically robust, hierarchically porous, and electrically conductive structure. The resulting 3D PAC filter preserved the high adsorption performance of PAC while providing a freestanding and reusable form. When operated as a conductive porous electrode (E-3D PAC), the filter enabled <i>in situ</i> generation of reactive oxygen species in the presence of H₂O₂, allowing oxidative degradation of adsorbed dyes and partial regeneration of the carbon surface within a single platform. Adsorption kinetics and isotherm analyses demonstrated strong affinity toward both anionic and cationic dyes. Electrochemical operation significantly enhanced dye removal through coupled adsorption-oxidation pathways, while the monolithic architecture maintained stable electrochemical performance over repeated treatment cycles. By unifying adsorption and electrochemical oxidation within a printable carbon framework, this work provides a scalable strategy for designing regenerable carbon-based filters for the treatment of dye-contaminated and complex wastewaters.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1569 - 1582"},"PeriodicalIF":6.2,"publicationDate":"2026-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148458700","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}

{"title":"High-strength strain-sensing composite material based on freestanding carbon nanotube films for real-time structural health monitoring","authors":"Rajath Alexander,&nbsp;Amit Kaushal,&nbsp;Rohan Rohilla,&nbsp;Jitendra Bahadur,&nbsp;Jyoti Prakash,&nbsp;Hassaan Butt,&nbsp;Dmitry V. Krasnikov,&nbsp;Albert G. Nasibulin,&nbsp;Kinshuk Dasgupta","doi":"10.1007/s42823-026-01088-5","DOIUrl":"10.1007/s42823-026-01088-5","url":null,"abstract":"<div><p>This study presents, for the first time, a composite material that integrates exceptional mechanical strength with sensitive strain-sensing capabilities, uniquely engineered for real-time structural health monitoring. In a novel approach, we employ freestanding carbon nanotube (CNT) films with aligned CNTs embedded in an epoxy matrix through vacuum bagging. The aligned CNT film was synthesized by floating catalyst chemical vapor deposition (FC-CVD). The parameters responsible for CNT alignment were determined and subsequently optimized, including winding rate, carrier gas flow, and precursor input, resulting in enhanced tensile strength and gauge factor (GF). This novel methodology yields an unprecedented tensile strength of 1.21 ± 0.06 GPa and a GF of 23, the highest GF for CNT composites with GPa-level strength. The remarkably elevated GF facilitates intrinsic strain detection through piezoresistivity, obviating the need for external sensors. This capability represents a significant advancement over traditional CNT powder-based composites that face challenges of agglomeration and low GF. The microstructural analysis identifies CNT bundle fracture as the primary failure mechanism, underscoring robust interfacial bonding. The study highlights the potential of CNT film-based composites in advanced structural applications, offering superior mechanical properties and integrated health monitoring capabilities through intrinsic strain sensing.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1749 - 1765"},"PeriodicalIF":6.2,"publicationDate":"2026-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148458821","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}

{"title":"Rotten roselle-derived activated carbon for high-performance supercapacitors: a sustainable waste-to-energy and dye removal approach","authors":"Babu Pejjai,&nbsp;Reddi Mohan Naidu Kalla,&nbsp;Rajesh Cheruku,&nbsp;Sivarama Krishna Lakkaboyana,&nbsp;Nadavala Siva Kumar,&nbsp;Mohammad Asif,&nbsp;Jaewoong Lee","doi":"10.1007/s42823-026-01086-7","DOIUrl":"10.1007/s42823-026-01086-7","url":null,"abstract":"<div><p>A new strategy has been developed to investigate a low-cost porous carbon electrode material derived from bio-waste rotten roselle, activated with potassium carbonate (K₂CO₃) under a nitrogen atmosphere via a direct activation method, without pre-carbonization. This activated carbon, referred to as Rotten Roselle Activated Carbon (RRAC), is intended for supercapacitor applications due to its anticipated high surface area, porous architecture, and favorable electrochemical properties. RRAC was characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS). The activated carbon composite exhibited a high specific surface area of 2225 m² g^− 1 and a substantial presence of micropores, which facilitate efficient ion and electron transport, thereby enhancing electrochemical performance. A maximum specific capacitance of 262 F g^− 1 at 0.5 A g^− 1 was obtained from the galvanostatic charge–discharge curve. Moreover, the RRAC material retained 89% of its capacitance after 5000 cycles, demonstrating excellent cycling stability. These results indicate that RRAC is a cost-effective and eco-friendly material for energy storage devices.</p></div>","PeriodicalId":506,"journal":{"name":"Carbon Letters","volume":"36 4","pages":"1727 - 1740"},"PeriodicalIF":6.2,"publicationDate":"2026-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148459099","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}