The current standard treatment regimen for patients with cervical cancer consists of a combination of radiotherapy and chemotherapy. However, the serious side effects often encountered with chemotherapy drugs greatly limits the effective doses that can be delivered, and hence the treatment of cervical cancer still faces strong challenges. In this study, carbon nanodots, nanodrugs with anti-cervical cancer activity and with negligible toxicity, were prepared from the precursor herbal extract ginsenoside Rg1. The surface of the Rg1 carbon nanodots is rich in hydrophilic functional groups, resulting in good dispersion in aqueous media and high biocompatibility. In Vitro experiments show that the Rg1 carbon nanodots have significant cytostatic and pro-apoptotic effects on HeLa cells, and could inhibit their migration and invasion. Experiments in tumor-bearing nude mice show that the Rg1 carbon nanodots could significantly inhibit tumor growth. Through qPCR validation, the Rg1 carbon nanodots were shown to enhance HeLa cell apoptosis, by regulating the expression levels of Cyto c, Caspase-9, Caspase-3, Bax, and Bcl-2, induce G2/M phase arrest by regulating CDK 1 and Cyclin B1 expression, and inhibit tumor cell migration by modulating CDH1 and β-catenin. Since the precursor Rg1 is a natural herbal extract, negligible toxic side effects were observed in nude mice. The work demonstrates that Rg1 carbon nanodots can be expected to become a potential nanomedicine against human cervical cancer with negligible toxic side effects and excellent therapeutic effects.
The growing demand for clean energy and sustainable technologies has intensified the need for efficient energy storage systems (EES) that support renewable energy integration while minimizing environmental impact. Biomass, an abundant and renewable resource, presents a cost-effective and eco-friendly pathway for producing advanced carbon materials, particularly heteroatom-doped graphene derivatives. This transformation aligns with circular economy principles by converting waste streams into high-performance materials for EES applications. This review provides a comprehensive analysis of biomassderived heteroatom-doped graphene materials, focusing on their synthesis, properties, and applications in electrochemical energy storage systems. It addresses a critical gap in the literature by systematically examining the relationship between biomass sources, doping strategies, and their impact on graphene’s electrochemical performance. The study highlights the role of heteroatom doping such as nitrogen, sulfur, phosphorus, and boron in enhancing graphene’s structural and electronic properties. These modifications introduce active sites, improve conductivity, and facilitate ion storage and transport, resulting in superior energy density, cycling stability, and charge–discharge performance in devices such as sodium/lithium-ion batteries, lithium-sulfur batteries, supercapacitors, and fuel cells. Recent advancements in green synthesis methods, including pyrolysis, hydrothermal carbonization, and chemical activation, are highlighted, focusing on their scalability and resource efficiency. By addressing both environmental and technological benefits, this review bridges the gap between laboratory research and practical applications. It underscores the critical role of biomass-derived graphene in achieving sustainable energy solutions and advancing the circular economy, offering a roadmap for future innovations in this rapidly evolving field.
In recent years, there has been growing interest in the potential applications of carbon-based non-metallic catalysts in various fields, such as electrochemical energy storage, electrocatalysis, thermal catalysis, and photocatalysis, owing to their unique physical and chemical properties. Modifying carbon catalyst surfaces or incorporating non-metallic heteroatoms, such as nitrogen (N), phosphorus (P), boron (B), and sulfur (S), into the carbon structure has emerged as a promising approach to improve the catalytic performance. This method enables the adjustment of the electronic structure of the carbon catalyst's surface, leading to the formation of new active sites or the reduction of side reactions, ultimately enhancing the catalyst's performance. Here, the preparation methods for doped non-metallic heteroatom carbon catalysts have been systematically explored, encompassing techniques, such as impregnation, pyrolysis, chemical vapor deposition (CVD), and templating. Finally, the existing challenges in the application of non-metallic atomic catalysts have been discussed, insights into potential future development opportunities and new preparation methods of carbon catalysts in the future have been offered.
Biochar is considered as key anode material for alkali metal (lithium, sodium, and potassium) ion batteries (AIBs) owing to its rich microstructural features, high specific surface area, active sites, excellent conductivity, and mechanical strength. The multidimensional structures and diverse functional groups of biochar make it enable easy modification to improve ion transport, interface deposition behavior, and electrolyte stability. In addition, biochar-based derivatives, such as silicon/biochar composite anode materials, combine the advantages of high-energy density and low lithiation potential of silicon materials, as well as the superior conductive ability and outstanding mechanical qualities of biochar. In this review, the microstructure, properties, and synthesis methods of biochar materials are systematically clarified, and then, their applications in AIBs are presented followed by summarizing the energy storage mechanism and advanced physicochemical characterizations. Common structural configurations and preparative technique for biochar/silicon-based composites are summarized, such as core–shell, yolk–shell, and embedded coating structures with improved electrochemical and mechanical stability. Finally, toward practical application of biochar and biochar-based derivatives in future AIBs, the issues and challenges are outlined.
As a key component of composite materials, the interface quality is crucial for determining the mechanical properties of composites. Carbon fiber sizing treatment significantly enhances the fiber-matrix interface, a process extensively utilized in the carbon fiber industry. This study synthesized an environmentally friendly waterborne polyurethane sizing agent and investigated the impact of molecular weight, a critical factor, on composite performance by varying the soft segment type in the polyurethane. This research provides insights into cost-effective and eco-friendly surface treatment methods for carbon fibers and the design of robust interface structures.
Coal pitch mainly consists of aromatic hydrocarbons, phenolic substances, and aliphatic hydrocarbons, the macromolecular structures formed by these cyclic and chain hydrocarbons through chemical bonding possess diversity and complexity. In this study, medium- and low-temperature coal tar pitch (LCTP) served as the primary material for the production of mesophase pitch via co-carbonization with hydrogenated tail oil (HTO). Aimed to clarify the effects of different amounts of HTO addition and analyze the mechanism of introducing naphthenic and aromatic hydrocarbons on the liquid phase carbonization process. When HTO additive amount is 30%, the carbonized product with the largest content of mature graphite crystals at 25.01%, and the smallest degree of defects. The analytical mechanism demonstrates that the condensation of naphthenic hydrocarbons introduced by HTO produces hydrogen radicals, the hydrogen transfer reaction saturates a significant quantity of free radicals generated within the system, thereby impeding further rapid condensation and curing, and decreasing the viscosity of the system. On the other hand, the aromatic hydrocarbons introduced undergo dehydrogenation and condensation to produce additional polycyclic aromatic hydrocarbons, thereby contributing to a more abundant carbon structure conducive to the development of mesophase pitch. The combined effect of aromatic hydrocarbons and naphthenic hydrocarbons facilitates the slow development of the mesophase structure into a broad-area optical structure. This study provides an effective method for improving the performance of coal-based mesophase pitch, which reduces the production cost and promotes the clean and high value-added utilization of limited resources.
As the demand for sustainable hydrogen (H₂) production grows, catalytic decomposition of methane (CDM) has emerged as a CO2- free pathway for H2 generation, producing valuable multi-walled carbon nanotubes (MWCNTs) as byproducts. This study examines the role of fuel type in shaping the properties and performance of NiOx/AlOx catalysts synthesized via solution combustion synthesis (SCS). Catalysts prepared with citric acid, urea, hexamethylenetetramine (HMTA), and glycine exhibited varying NiO nanoparticle (NP) sizes and dispersions. Among them, the HMTA catalyst achieved the highest Ni dispersion (~ 3.2%) and specific surface area (21.6 m2/ gcat), attributed to vigorous combustion facilitated by its high pH and amino-group-based fuel. Catalytic tests showed comparable activation energy (55.7–59.7 kJ/mol) across all catalysts, indicating similar active site formation mechanisms. However, the HMTA catalyst demonstrated superior CH4 conversion (~ 68%) and stability, maintaining performance for over 160 min under undiluted CH₄, while others deactivated rapidly. MWCNT characterization revealed consistent structural properties, such as graphitization degree and electrical conductivity, across all catalysts, emphasizing that fuel type influenced stability rather than MWCNT quality. H2 temperature-programmed reduction ( H2-TPR) analysis identified moderate metal-support interaction (MSI) in the HMTA catalyst as a key factor for optimizing stability and active site utilization. These findings underscore the importance of fuel selection in SCS to control MSIs and dispersion, offering a strategy to enhance catalytic performance in CDM and other thermocatalytic applications.
The high value-added utilization of traditional coal resources is one of the important ways to achieve the strategic goals of carbon peaking and carbon neutrality. Simultaneously, coal-based carbon materials, noted for their cost-effectiveness, superior conductivity, and inherent stability, are emerging as promising candidates for next-generation capacitor technologies. This research presents a series of coal-derived porous carbon by pyrolysis using low rank lignite as raw material and KOH as activator, which are employed in symmetrical supercapacitors filled with liquid electrolytes. The physicochemical properties of the as-prepared electrode materials are characterized by means of scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and their supercapacitive performance are evaluated through cyclic voltammetry and galvanostatic charge–discharge tests. The coal-based porous carbon electrode prepared at an activation temperature of 800 °C (KOH-800) exhibits a specific capacitance of 142.2 F g− 1 at a current density of 1 A g− 1, and retaining 80% of its capacitance (114.0 F g− 1) even at 10 A g− 1. The fabricated liquid supercapacitor displays a power density of 999.8 W kg− 1 and an energy density of 19.4 Wh kg− 1 at a current density of 1 A g− 1. Undergoing 10,000 cycles at 2 A g− 1, the supercapacitor maintains nearperfect capacitance retention and coulombic efficiency close to 100%, demonstrating its excellent durability and stability for supercapacitor applications.
Graphene quantum dots have recently gained significant attention for their potential application in the development of optoelectronic materials. The present study focused on the ultrasonic method to synthesize white-light-emitting graphene quantum dots from coal soot in just 2 min at room temperature. The white-light emission was achieved in solution and polymeric film with good Commission Internationale del’Eclairage index (0.28, 0.33) and (0.25, 0.30), respectively. The graphene quantum dots cover a significant fraction of the visible region in the emission spectrum with two prominent bands at 475 and 635 nm at 380 nm photoexcitation, corresponding to monomer and J-aggregate emission. The strong reducing and basic nature of the ethylene diamine facilitated the preparation of self-assembled J-aggregate graphene quantum dots through hydrogen bonding and electrostatic interaction. The mechanism of origin J-aggregate emission in the prepared graphene quantum dots was studied using UV–visible absorption, steady-state, lifetime fluorescence spectroscopy, and zeta potential. The as-synthesized graphene quantum dots are successfully coated on the UV-LEDs' surface and emit white light on the applied voltage. The colours of red, green, blue, and yellow balls appear significantly in the lighting of prepared white LEDs.
Graphite cores in nuclear reactors are critical components subjected to severe irradiation conditions. Despite the known susceptibility of graphite to radiation-induced damage, detailed microstructural analyses are limited. Existing works of literature have identified changes in crystallite morphology and orientation as early indicators of structural degradation, but the precise micro-mechanisms are not fully understood. This research explicates these micro-mechanisms using advanced analytical transmission electron microscopy (TEM) to examine irradiated graphite at doses up to 1 dpa (displacements per atom). TEM imaging and diffraction analysis captured detailed changes in crystallite structure. Even at low radiation doses (~ 0.1 dpa), a 15% alteration in crystallite morphology and orientation was observed. Significant crystal lattice rotations up to 5 degrees and micro-deformations were also detected. Additionally, the formation of micro-kinks and kink bands, ranging from 50 to 200 nm, were identified as potential deformation processes, consistent with phenomena in other layered materials. These results advance our understanding of the micro-mechanisms driving structural degradation and deformation in irradiated graphite. This research has significant implications for developing improved models and strategies to enhance the performance and longevity of graphite cores in nuclear reactors, contributing to the advancement of nuclear energy technology.
This study incorporates the formation of carbon quantum dots (CQDs) via a hydrothermal approach, recording the first-time use of castor leaves as a natural precursor. The used precursor offers various benefits including novelty, abundance, elemental composition, and biocompatibility. CQDs were further characterized with multiple techniques including high-resolution transmission electron microscope (HR-TEM), X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), Fouriertransform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy, Zeta analysis, and optical spectroscopy. They are fundamentally composed of carbon (71.37%), nitrogen (3.91%), and oxygen (24.73%) and are nearly spherical, and uniformly distributed with an average diameter of 2.7 nm. They possess numerous interesting characteristics like broad excitation/emission bands, excitation-sensitive emission, marvelous photostability, reactivity, thermo-sensitivity, etc. A temperature sensor (thermal sensitivity of 0.58% C− 1) with repeatability and reversibility of results is also demonstrated. Additionally, they were found selective and sensitive to ions in aqueous solutions. So, they are also utilized as a fluorescent probe for metal ion ( Fe3+) sensing. The lowest limit of detection (LOD) value for the current metal ion sensor is 19.1 μM/L.
This study introduces a cost-effective electrochemical exfoliation technique for producing highly crystalline graphene from graphite. By optimizing key exfoliation parameters, including voltage, electrolyte concentration, and temperature, the efficiency of the exfoliation process and the quality of the resulting graphene were significantly improved. To further enhance crystallinity, minimize defect sites, and achieve superior material properties, the as-prepared electrochemically exfoliated graphene (AeEG) underwent post-heat treatment at temperatures ranging from 1500 to 2950 °C. When employed as a conductive additive, eEGs heat-treated at 1800 °C or higher significantly improved both cycle stability and rate performance in LIB coin cells, while maintaining a discharge capacity approximately 10–12 mAh/g higher than that of the control, which utilized Super P. The enhanced performance is attributed to the formation of an efficient conductive network and superior electron transport properties, driven by the high crystallinity and large aspect ratios of the heat-treated eEGs. These findings highlight the potential of eEG as a highly effective conductive additive for advanced battery industries, offering significant improvements in energy storage performance, specific capacity, and rate characteristics.
This study introduces a novel method for synthesizing carbon nanotube (CNT) fibers using floating catalyst chemical vapor deposition (FC-CVD) in an open-atmosphere without the need for hydrogen as a carrier gas. Traditional FC-CVD techniques depend on hydrogen gas and require a harvest box with inert gas purging, which restricts scalability. Our approach utilizes nitrogen gas as the sole carrier, allowing for CNT fiber production without a harvest box. To understand the spinning process mechanism in an open-atmosphere, we conducted thermodynamic and computational fluid dynamics (CFD) analyses. Methanol was selected as the carbon source based on thermodynamic calculations, which revealed that at high temperatures, methanol forms CO and H2 as thermodynamically stable species instead of carbon (C), thereby preventing soot formation. Moreover, methanol undergoes catalytic cracking exclusively in the presence of catalysts, further preventing soot formation. This approach allows operation at high partial pressure, even above the upper explosive limit (UEL), effectively preventing combustion. A 600 mm cooling zone was incorporated into the reactor to lower the outlet gas temperature below methanol's auto-ignition point, mitigating combustion risks. CFD calculations were employed to determine the necessary cooling zone length. Additionally, we developed a predictive model using the XGBoost machine learning method to efficiently map the parameter space for CNT fiber spinning, achieving an accuracy of 95.24%. The resulting CNT fibers demonstrate high electrical conductivity (240 ± 24 S/cm) and a low ID/ IG ratio, indicating a high degree of crystallinity.
Incorporation of pseudocapacitive materials into porous carbon is a promising strategy to boost electrochemical performance. Herein, composite of biomass-derived porous carbon and MnO2 (a typical pseudocapacitive material) was facilely fabricated through an in-situ synthesis approach with sorghum seeds derived porous carbon (SSC) as the skeleton for MnO2 deposition. The as-prepared composite ( MnO2@SSC) exhibits hierarchical porous structure with abundant interlaced MnO2 nanowires wrapping on the surface. While the porous structure is beneficial to the active sites exposure and electrolyte ions transport, the interlaced three-dimensional (3D) network of MnO2 nanowires significantly boosts the tolerance toward volume shrinkage/expansion during the cyclic process. Consequently, the MnO2@ SSC-based electrode delivered quite promising supercapacitive performance including superior specific capacitance of 482.7 F/g at 0.5 A/g, outstanding long-term cycling stability (95.8% specific capacitance retention after 20,000 cycles) and high energy density of 13.7 Wh/kg at power density of 298.1 W/kg. Furthermore, all-solid-state flexible supercapacitor based on MnO2@ SSC can be facilely bent to various angles (0° to 150°) without significant degradation in the capacitive performance. This study provides a facile, cost-effective, and sustainable approach for the fabrication of high-performance electrode materials.
Using durian shell as a carbon source and triethanolamine as a nitrogen dopant, nitrogen-doped carbon dots (N-CDs) were prepared via the hydrothermal method. First, by exploring different reaction times, reaction temperatures, and carbon source/dopant ratios to synthesize nitrogen-doped carbon dots, it is concluded that the best process conditions are 200 ℃, reaction time being 15h, and the dopant addition amount being 2mL. Structure and characteristics of the synthesized CDs were analyzed using X-ray photoelectron spectroscopy, Fourier-transform infrared, fluorescence (FL), ultraviolet–visible absorption, and Raman spectra. The N-CDs showed blue FL with a quantum efficiency of 4.28%. The FL characteristics of the N-CDs were utilized for ion detection, which demonstrated that MnO− 4 and Cr 2 O2− 7 ions caused distinct FL quenching through static quenching, while other ions had no significant quenching effect. The detection limits for MnO− 4 and Cr 2 O2− 7 were 37.5 and 46.2 nM, respectively. The N-CDs were subsequently employed to detect these ions in actual water samples, producing satisfactory results. Therefore, the preparation of N-CDs using durian shell as raw material and its application in practical detection work have good application feedback, which not only provides a new way for the reuse of fruit and vegetable wastes but also provides a new detection means for environmental monitoring pollutants.
Quantum dot nanocomposite-based luminescent materials have gained attention for solid-state lighting and optical displays. This study presents a one-step, eco-friendly hydrothermal process to synthesize nitrogen, potassium, and calcium-doped carbon quantum dots (N, K, Ca-doped CQDs) from the flower extract of Mesembryanthemum crystallinum L. (ice plant). The CQDs were characterized using HRTEM, EDX, SAED, XPS, XRD, NMR, FTIR, zeta potential, UV–Vis, and photoluminescence spectroscopy. HRTEM revealed an average particle size of 4.6 nm, with a range of 2 to 7 nm. The CQDs exhibited a quantum yield of 20%, excellent water solubility, photostability, and greenish fluorescence under UV (365 nm). The fluorescence spectra were analyzed using CIE (Commission Internationale de l’Eclairage) chromaticity coordinates to determine the emitted color. The fluorescence emission behavior was influenced by solvent polarity, locally excited (LE) states, intramolecular charge transfer (ICT) processes, and hydrogen bonding. The hydrogen bonds between N, K, Ca-doped CQDs and DI water likely enhanced the stability of the ICT state, resulting in a red shift in fluorescence. Additionally, we developed an eco-friendly wheat-starch-based bioplastic nanocomposite by embedding the CQDs. The effects of CQD concentration and pH sensitivity on luminescent properties were explored. Finally, we demonstrated a practical application by designing a conceptual nameplate-like calligraphy using the optimized CQDs@bioplastic nanocomposite film (CQD concentration: 240 mg/mL, pH: 2.7), highlighting its potential for luminescent film applications.
In this work, we reported a method for a fabrication of bead-on-string structured g-C3N4/CoFe2O4 composite nanofibers by electrospinning coupled with in situ calcination. For the first time, this catalyst effectively removed high concentrations of mixed organic pollutants through the synergistic effects of adsorption and photocatalysis. The composite materials removal efficiency of adsorption and photocatalytic for high concentrations of organic pollutants in wastewater can exceed 90%. Surface potential analysis using in situ Kelvin probe force microscopy demonstrated the electron transfer pathways on the catalyst surface. The formation of the heterojunction was demonstrated through DFT calculations to significantly enhance the efficiency of electron–hole separation. This work provided valuable insights for the development of efficient catalysts for the synergistic adsorption-photocatalytic treatment of environmental pollutants, thus addressing increasingly severe environmental challenges.
Efforts to mass-produce high-quality graphene sheets are crucial for advancing its practical and industrial applications across various fields. In this study, we present an innovative electrochemical exfoliation method designed to enhance graphene quality and increase yield. Our approach combines two key techniques: expanding the tightly packed graphite interlayer used as the electrode medium and precisely controlling voltage polarity. The dual-exfoliation technique optimizes the use of anions and cations of varying sizes in the electrolyte to facilitate meticulous intercalation, allowing ions to penetrate deeply and evenly into the graphite interlayer. The newly designed dual-exfoliation technique using biased switching polarity minimizes the generation of oxygen-containing radicals, while the incorporation of expanded graphite accelerates exfoliation speed and reduces oxidation, maintaining high graphene purity. With these improvements, we produced 1–3 layer graphene sheets with minimal defects ( ID/IG ≈ 0.13) and high purity (C/O ratio ≈ 20.51), achieving a yield 3.1 times larger than previously reported methods. The graphene sheets also demonstrated excellent electrochemical properties in a three-electrode system, with an electrical conductivity of 92.6 S cm− 1, a specific capacitance of 207.4 F g− 1, and a retention of 94.8% after 5,000 charge/discharge cycles, highlighting their superior stability and performance.
Marine biomass (MB) offers an environmentally friendly and readily available carbon source from the ocean. However, the high concentration of alkali and alkaline earth metals (AAEMs) in MB typically reduces the carbon yield and inhibits micropore formation during heat treatment due to catalytic gasification. In this study, we successfully synthesized activated carbon (AC) with a high specific surface area (> 1,500 m2/ g) and significant mesopore content (60%, mean pore size: 3.4 nm) from MB by employing preheating, controlled acid purification, and CO₂ activation. The formation of mesopores in the MB-derived AC was driven by catalytic gasification induced by intrinsic and residual AAEMs during preheating and physical activation processes. We evaluated the potential of the MB-derived AC as an electrode material for electric doublelayer capacitors (EDLCs). The material demonstrated high specific capacitance values of 25.9 F/g and 29.4 F/g at 2.7 V and 3.3 V, respectively, during charge–discharge cycles. These high capacitance values at elevated voltages were attributed to the increased number of solvated ions (e.g., 1.93 mmol/g at 3.3 V) present in the mesopores. Fluorine-19 nuclear magnetic resonance (19F solid-state NMR) analysis revealed a substantial increase in solvated ion concentration within the mesopores of the MB-derived AC electrode at 3.3 V, demonstrating enhanced ion mobility and diffusion. These findings highlight the potential of MB-derived AC as a promising electrode material for high-voltage energy storage applications.
Lightweight materials with favorable mechanical, electromagnetic interference (EMI) shielding and thermal insulation performance are highly desirable for applications in harsh environments. Polyacrylonitrile (PAN)-derived carbon nanofibers/ carbon foams containing hollow closed microspheres have been developed, and their balanced multifunction is noteworthy. The addition of CNFs resulted in a gradual enhancement of the specific compressive strength of carbon foams, reaching a maximum value of 26.6 MPa·cm3·g−1 with content of 3 wt.% CNFs, improved by as much as 62%, compared to that of pristine carbon foam. Additionally, the fracture toughness exhibited the maximum fracture energy absorption of 118.6 MJ‧m−3 at 3 wt.% CNFs. The appropriate amount of CNFs and hollow carbon microspheres resulted in effective toughening and strengthening of carbon foams. Incorporation of CNFs into carbon foams also resulted in an improvement in their electromagnetic shielding performance, with a maximum EMI-shielding effectiveness of 65.8 dB. Reflection loss was the main contributor to electromagnetic shielding efficiency. Furthermore, carbon foams presented remarkable high-temperature thermal insulation, with a minimum thermal conductivity of merely 0.509 W·m−1·K−1 at 800 °C. They exhibited the ability to withstand the butane flame ablation at 1000 °C, which substantiated the potential of carbon foams for aerospace applications.