Synthesis Of Carbon Materials Research Articles

Biomass-Derived Carbon Materials for Advanced Metal-Ion Hybrid Supercapacitors: A Step Towards More Sustainable Energy

Modern research has made the search for high-performance, sustainable, and efficient energy storage technologies a main focus, especially in light of the growing environmental and energy-demanding issues. This review paper focuses on the pivotal role of biomass-derived carbon (BDC) materials in the development of high-performance metal-ion hybrid supercapacitors (MIHSCs), specifically targeting sodium (Na)-, potassium (K)-, aluminium (Al)-, and zinc (Zn)-ion-based systems. Due to their widespread availability, renewable nature, and exceptional physicochemical properties, BDC materials are ideal for supercapacitor electrodes, which perfectly balance environmental sustainability and technological advancement. This paper delves into the synthesis, functionalization, and structural engineering of advanced biomass-based carbon materials, highlighting the strategies to enhance their electrochemical performance. It elaborates on the unique characteristics of these carbons, such as high specific surface area, tuneable porosity, and heteroatom doping, which are pivotal in achieving superior capacitance, energy density, and cycling stability in Na-, K-, Al-, and Zn-ion hybrid supercapacitors. Furthermore, the compatibility of BDCs with metal-ion electrolytes and their role in facilitating ion transport and charge storage mechanisms are critically analysed. Novelty arises from a comprehensive comparison of these carbon materials across metal-ion systems, unveiling the synergistic effects of BDCs’ structural attributes on the performance of each supercapacitor type. This review also casts light on the current challenges, such as scalability, cost-effectiveness, and performance consistency, offering insightful perspectives for future research. This review underscores the transformative potential of BDC materials in MIHSCs and paves the way for next-generation energy storage technologies that are both high-performing and ecologically friendly. It calls for continued innovation and interdisciplinary collaboration to explore these sustainable materials, thereby contributing to advancing green energy technologies.

Shear Field-Controlled Synthesis of Nitrogen-Doped Carbon Nanochains Forest with High-Density sp3 Defects for Efficient CO2 Electroreduction Reaction.

Defect engineering and nitrogen doping being effective strategies for modulating the surface chemical state of the carbon matrix have been widely explored to promote the catalytic activity in the territory of electrochemical energy storage and conversion devices. However, the controllable synthesis of carbon material with high-density specific defects and high nitrogen doping is still full of challenges. Here, we first synthesize one-dimensional necklace-like nitrogen-doped carbon nanochains (N-CNCs) with abundant defects on carbon fiber paper (CFP) by chemical vapor deposition (CVD) method. The resultant nanostructures are a bunch of interconnected carbon spheres with a hollow structure at the internode and present the complete one-dimensional nanochain configuration. Specifically, the N-CNCs with a corrugated surface possesses high content of sp3 defects (31.2%) and nitrogen (23.6 at %). Combining finite element analysis and experimental results, it reveals that the robust shear field generated by etching gas releasing from thermal decomposition of melamine in situ modulates the CVD process via changing the size and force environment of the metal catalyst droplets for formation of N-CNCs. Benefiting from the high ratio of sp3/sp2 and nitrogen doped on the surface, the N-CNCs@CFP displays a superior electrocatalytic performance for CO2RR, delivering CO Faradaic efficiency of 95.9% and a current density of 23.2 mA cm-2 at -0.86 V vs RHE. This work provides promising synthesis strategy and some inspirations for construction of ultradense and specific defects coupling with nitrogen doping sites into carbon materials to achieve high-efficiency electrocatalysis applications.

Bio-based protic salts as precursors for sustainable free-standing film electrodes

Transforming amines with low boiling points and high volatilities into protic salts is a versatile strategy to utilize low molecular weight compounds as precursors for N-doped carbon structures in a straightforward carbonization procedure. Herein, conventional mineral acids commonly used for the synthesis of protic salts were replaced by bio-derived phytic acid, which, combined with various amines and amino acids, yielded partially or fully bio-derived protic salts. The biomass-based salts showed higher char-forming ability than their mineral acid-based analogs (up to 55.9% at 800°), simultaneously providing carbon materials with significant porosity (up to 1177 m2g−1) and a considerable level of N,P,O-doping. Here, we present the first comprehensive study on the correlation between the structure of the bio-derived protic precursors and the properties of derived carbon materials to guide future designs of biomass-derived precursors for the one-step synthesis of sustainable carbon materials. Additionally, we demonstrate how to improve the textural properties of the protic-salt-derived carbons (which suffer from high brittleness) by simply upgrading them into highly flexible nanocomposites using high-quality single-walled carbon nanotubes. Consequently, self-standing electrodes for the oxygen reduction reaction were created.

Synthesis of natural oxygen-doped bamboo-derived hierarchical micro-mesoporous composite carbon materials using a green activation strategy

Utilizing biomass waste to synthesize hierarchical micro-mesoporous composite carbon materials for application in the field of supercapacitors realized green and sustainable energy development. This paper efficiently synthesized natural O-doped carbon materials using bamboo as biomass material by simple air pre-oxidation and secondary carbonization methods. Among them, KCl acted as a recyclable templating agent and flame retardant, facilitating the construction of mesoporous structures. The green activator CH3COOK promoted the generation of micropores. The combination of dual activation strategies (physical and chemical) contributed to the conversion of bamboo to hierarchical micro-mesoporous composite carbon materials. During pre-carbonization, air was used as a natural dopant which etched the carbon material and promoted the creation of oxygenated functional groups. The best carbon material exhibited an excellent electrochemical capacity of 321.65 F/g in 6 M KOH electrolyte. Furthermore, the symmetric supercapacitor exhibited high cycling stability (95.52 %) and outstanding power density. This work provided a new idea for preparing controllable biomass-derived carbon materials, while offering a reference for applying dual activation strategies in carbon material synthesis.

Pore structure and oxygen content design of amorphous carbon toward a durable anode for potassium/sodium‐ion batteries

AbstractBoth sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) are considered as promising candidates in grid‐level energy storage devices. Unfortunately, the larger ionic radii of K+ and Na+ induce poor diffusion kinetics and cycling stability of carbon anode materials. Pore structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration, increasing the transport channels, and alleviating the volume change. However, traditional pore‐forming agent‐assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon materials. Herein, porous carbon materials (Ca‐PC/Na‐PC/K‐PC) with different pore structures have been prepared with gluconates as the precursors, and the amorphous structure, abundant micropores, and oxygen‐doping active sites endow the Ca‐PC anode with excellent potassium and sodium storage performance. For PIBs, the capacitive contribution ratio of Ca‐PC is 82% at 5.0 mV s−1 due to the introduction of micropores and high oxygen‐doping content, while a high reversible capacity of 121.4 mAh g−1 can be reached at 5 A g−1 after 2000 cycles. For SIBs, stable sodium storage capacity of 101.4 mAh g−1 can be achieved at 2 A g−1 after 8000 cycles with a very low decay rate of 0.65% for per cycle. This work may provide an avenue for the application of porous carbon materials in the energy storage field.

Utilizing Carbonaceous Materials Derived from [BMIM][TCM] Ionic Liquid Precursor: Dual Role as Catalysts for Oxygen Reduction Reaction and Adsorbents for Aromatics and CO2.

This work presents the synthesis of N-doped nanoporous carbon materials using the Ionic Liquid (IL) 1-butyl-3-methylimidazolium tricyanomethanide [BMIM][TCM] as a fluidic carbon precursor, employing two carbonization pathways: templated precursor and pyrolysis/activation. Operando monitoring of mass loss during pyrolytic and activation treatments provides insights into chemical processes, including IL decomposition, polycondensation reactions and pore formation. Comparatively low mass reduction rates were observed at all stages. Heat treatments indicated stable pore size and increasing volume/surface area over time. The resulting N-doped carbon structures were evaluated as electrocatalysts for the oxygen reduction reaction (ORR) and adsorbents for gases and organic vapors. Materials from the templated precursor pathway exhibited high electrocatalytic performance in ORR, analyzed using Rotating Ring-Disk electrode (RRDE). Enhanced adsorption of m-xylene was attributed to wide micropores, while satisfactory CO2 adsorption efficiency was linked to specific morphological features and a relatively high content of N-sites within the C-networks. This research contributes valuable insights into the synthesis and applications of N-doped nanoporous carbon materials, highlighting their potential in electrocatalysis and adsorption processes.

Synthesis of N/P/S Co-doped porous carbons by carbonizing polyphosphazene microspheres for highly selective adsorption of Pb (II)

Heteroatom-doping has emerged as a promising approach for enhancing the properties of carbon materials, particularly in the treatment of heavy-metal wastewater. However, the simultaneous synthesis of multi-heteroatom co-doped carbon materials poses significant complexity and challenges. Consequently, there is an increasing demand for the development of non-toxic and straightforward methods to prepare such materials. In this study, we present a novel approach for the synthesis of N/P/S co-doped porous carbonaceous adsorbents using polyphosphazene as precursors. Our focus is specifically on their effectiveness in adsorbing Pb (II). The results reveal that the synthesized adsorbents, denoted as carbonized polyphosphazene or CZ-600 exhibited a high carbon content co-doped with N, P and S atoms, as well as an abundance of oxygen-containing functional groups and a porous structure. These characteristics collectively contribute to the exceptional adsorption capacity of CZ-600 for Pb (II), with a maximum adsorption capacity of 121.7 mg/g and an equilibrium time as short as 20 min. Further investigations of the adsorption process involve fitting adsorption isotherm, kinetic, and thermodynamic models, revealing chemical adsorption as the predominant mechanism, supported by contributions from micropore adsorption and electrostatic interactions. This work proposes a sustainable and efficient solution for the treatment heavy-metal wastewater, which not only advances the understanding of heteroatom-doped carbon materials but also provides valuable insights into their practical applications in environmental remediation.

Revolutionizing Zn-Air batteries with chainmail catalysts: Ultrathin carbon-encapsulated FeNi alloys on N-doped graphene for enhanced oxygen electrocatalysis

The sluggish kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) pose significant challenges for the viability of rechargeable Zn-air batteries. Developing efficient, cost-effective, stable, and dual-purpose oxygen electrocatalysts remains a formidable hurdle. In this study, we successfully synthesized a highly promising chainmail catalyst named FeNi@NC, comprising ultrathin carbon shells encapsulating FeNi alloy nanoparticles on N-doped graphene-like nanosheets. The strong synergistic effects between FeNi alloys and N-doped carbon shells result in outstanding bifunctional catalytic activity, particularly in alkaline media. Consequently, Zn-air batteries incorporating FeNi@NC as the catalyst demonstrate exceptional performance, operating reliably at high power density with extended lifespan. Furthermore, computational analyses provided further confirmation of the catalytic activity and revealed that the electron transfer from FeNi alloy nanoparticles to the carbon shells activates the carbon surface, leading to enhanced catalytic performance. This research not only sheds light on the rational design and synthesis of heteroatom-doped carbon materials supporting the growth-constrained transition metal alloys but also offers a practical solution for advancing the application of Zn-air batteries.

Soluble starch-derived porous carbon microspheres with interconnected and hierarchical structure by a low dosage KOH activation for ultrahigh rate supercapacitors

The developed porous structure and high density are essential to enhance the bulk performance of carbon-based supercapacitors. Nevertheless, it remains a significant challenge to optimize the balance between the porous structure and the density of carbon materials to realize superior gravimetric and areal electrochemical performance. The soluble starch-derived interconnected hierarchical porous carbon microspheres were prepared through a simple hydrothermal treatment succeeded by chemical activation with a low dosage of KOH. Due to the formation of interconnected spherical morphology, hierarchical porous structure, reasonable mesopore volume (0.33 cm3 g−1) and specific surface area (1162 m2 g−1), the prepared carbon microsphere has an ultrahigh capacitance of 394 F g−1 @ 1 A g−1 and a high capacitance retention of 62.7 % @ 80 A g−1. The assembled two-electrode device displays good cycle stability after 20,000 cycles and an ultra-high energy density of 11.6 Wh kg−1 @ 250 W kg−1. Moreover, the sample still exhibits a specific capacitance of 165 F g−1 @ 1 A g−1 at a high mass loading of 10 mg cm−2, resulting in a high areal capacitance of 1.65 F cm−2. The strategy proposed in this study, via a low-dose KOH activation process, provides the way for the synthesis of high-performance porous carbon materials.

Toward strategical bottom-up synthesis of carbon materials with exceptionally high pyrrolic-nitrogen content: Development of screening techniques

Carbon materials with pyrrolic nitrogen are expected to be applied to electrodes and catalysts because of their excellent high charge density and reactivity. However, pyrrolic nitrogen is known to be easily decomposed or changed into other functional groups at high temperatures, causing difficulty in controlling the structure of carbon materials. In this study, carbon materials with exceptionally high percentages (maximum 94%) and contents (maximum 7.0 at%) of pyrrolic nitrogen were synthesized using brominated precursors with pyrrolic nitrogen at 873 K. The positions and the number of introduced bromo groups influenced percentages of pyrrolic nitrogen after carbonization. By combining density functional theory calculations and molecular dynamics simulation with a reactive force field (ReaxFF) in addition to experimental analyses, screening techniques of precursors for preparing carbon material with high percentages of pyrrolic nitrogen were developed. Also, it was revealed that the lowering carbonization temperature by brominating precursors was indispensable for protecting thermally unstable pyrrolic nitrogen and it was also revealed that the presence of bromo groups at the position of carbon atoms far from pyrrolic nitrogen in the precursor was the key to avoid formation of tertiary nitrogen and hydrogenation of pyrrolic nitrogen, resulting in the high percentage of pyrrolic nitrogen.

Biochar for supercapacitor electrodes: Mechanisms in aqueous electrolytes

AbstractThe utilization of biomass materials that contain abundant carbon–oxygen/nitrogen functional groups as precursors for the synthesis of carbon materials presents a promising approach for energy storage and conversion applications. Porous carbon materials derived from biomass are commonly employed as electric‐double‐layer capacitors in aqueous electrolytes. However, there is a lack of detailed discussion and clarification regarding the kinetics analysis and energy storage mechanisms associated with these materials. This study focuses on the modification of starch powders through the KOH activation process, resulting in the production of porous carbon with tunable nitrogen/oxygen functional groups. The kinetics and energy storage mechanism of this particular material in both acid and alkaline aqueous electrolytes are investigated using in situ attenuated total reflectance‐infrared in a three‐electrode configuration.

Effect of asphalt component distribution characteristics in layered porous carbon on performance of supercapacitors

Petroleum asphalt, characterized by its rich aromatic hydrocarbon structures and high carbonization yield, emerges as an ideal precursor for generating porous carbons intended for supercapacitors (SCs). Despite asphalt's classification into four distinct components, the intricate composition due to its diverse sources still presents an unresolved challenge when it comes to elucidating the predominant structural characteristics underlying porous carbons. In the present investigation, we adopted potassium bicarbonate (KHCO3) as a templating agent, and the potassium-containing compounds were thermally polymerized with carbon-based free radicals to facilitate the synthesis of porous carbon materials through carbonization process. We observed that the fabricated porous carbon with a substantial content of heavy fraction (68.5 wt. %) demonstrated the maximal pore volume (1.02 cm3 g−1) and specific surface area (SSA) of 1229 m2 g−1, yielding in the power density of 625 W kg−1 at the energy density of 17.88 W h kg−1 used 1 M tetraethylammonium tetrafluoroborate in acetonitrile (TEATFB/AN). Notably, we corroborated the reliability of the entire process through a rigorous scaling-up experiment to 10 g, demonstrating entirely consistent performance. Our research introduces a novel avenue for strategically selecting petroleum asphalt precursors, with the overarching objective of producing cost-effective carbon materials endowed with commendable performance attributes.

Synthesis and electrochemical performance of biomass-derived porous carbon materials for supercapacitors

Synthesis and electrochemical performance of biomass-derived porous carbon materials for supercapacitors

Enhancing CO2 adsorption performance of porous nitrogen-doped carbon materials derived from ZIFs: Insights into pore structure and surface chemistry

In this work, a novel approach for the synthesis of porous nitrogen-doped carbon materials (PNCs) with a highly microporous structure through low-temperature carbonization of ZIF-8 and ZIF-61 assisted by KCl and NaCl is reported. The introduction of KCl and NaCl during the carbonization process can adjust the surface chemical properties and pore structures of the PNCs derived from ZIF-8 and ZIF-61. The effects of pore structures and surface groups of PNCs on CO2 adsorption capacity are explored. Results show that the cumulative pore volume in the pore size range of 5–7 Å (V5-7 Å), pyrrolic-N content, and COOH content exert favorable influences on CO2 adsorption capacity at 1 bar and 25 °C. Notably, V5-7 Å is the key factor in enhancing the CO2 adsorption capacity of PNCs. Moreover, the degree of contribution of V5-7 Å, V7-9 Å, pyrrolic-N content, pyridinic-N content, and COOH content to the CO2 adsorption capacity is evaluated by establishing a multiple linear regression equation, and the results show that on the basis of PNCs possessing optimum pore structures (V5-7 Å > 0.10 cm3/g), pyrrolic-N content in PNCs becoming the dominant contributor to CO2 adsorption capacity. The as-prepared 2CN8-KCl-600 sample demonstrates high CO2 adsorption capacity, which reaches 4.61 mmol/g at 25 °C and 6.70 mmol/g at 0 °C (1 bar), respectively. Besides, 2CN8-KCl-600 exhibits high CO2/N2 selectivity (39.5) under the typical flue gas scenario and high cycling stability. This work offers a novel perspective on preparing highly efficient carbon-based adsorbents for CO2 and provides the fundamental understanding for enhanced CO2 adsorption performance on PNCs.

Scavenge of Hazardous Metal Ions Using Decorated Nanometal on Carbon Nanomaterial Synthesized from Cotton

Abstract: Eradicating hazardous materials using carbon nanomaterials (CNMs) is a cutting-edge approach in environmental remediation. The study involves procurement of plant material cotton as a feasible precursor for the synthesis of carbon materials which is further activated by using alkali solution. Activated carbon was decorated with copper nanoparticles to create a copper decorated CNMs. The effective adsorption of Cd+2 and As+3 is 85% to 90% at pH 6 and 7 respectively. Thus, this recently developed cost-effective novel adsorbent CNMs can be used to mitigate the Cd +2 and As+3 even at a very low concentration level. The prepared adsorbent was characterized by various analytical techniques such as SEM, TEM, Raman and XRD. The specific surface area and pore volume was confirmed by BET.

Sulfur-Doped porous carbon Adsorbent: A promising solution for effective and selective CO2 capture

The effective and selective capture of CO2 through the rational design of microstructures and the synthesis of carbon materials with enriched surface functionality is of utmost importance in mitigating CO2 emissions. In this study, we successfully prepared a novel type of S-doped porous carbon material with a high surface area and a significant volume of micropores in a straightforward manner. This was achieved by pyrolyzing carbonized coconut shells (CS) with potassium thiosulfate K2S2O3 (PT) as an activating and sulfur supply agent. By adjusting the pyrolysis temperature within the range of 650–750 °C, we obtained carbon materials with varying surface areas (887–1924 m2/g), pore volumes (0.35–0.95 cm3 g−1), and a homogeneous distribution of sulfur content (up to 12.26 wt%) within the carbon framework. The optimal S-doped porous carbon demonstrated the adsorption capacities of 3.59 mmol g−1 at 25 °C and 5.31 mmol g−1 at 0 °C under 1 bar. Additionally, the prepared sorbent exhibited favorable CO2/N2 selectivity, high isosteric heat, and stable cycling performance. These excellent CO2 capture properties can be attributed to the materials' high microporosity and well-dispersed sulfur functionality in the carbon framework. Collectively, these findings highlight the potential of these novel carbon materials with heteroatom doping as efficient adsorbents for the selective capture of CO2, presenting a viable solution in the quest for effective CO2 mitigation.

Synthesis and electrochemical properties of porous carbon materials from sludge sources

Anaerobic digestion sludge technology is a green and efficient method of treating sludge. However, the presence of humic acid (HA) in sludge can inhibit methanogenic efficiency, and it is necessary to reduce its impact on biogas production by removal or pretreatment. HA, a graphene oxide material can be used to produce high-performance energy-storage materials. Thus, this study examined the sludge source of HA as a precursor, and different electrode materials were prepared by varying the reaction conditions. The structure and electrochemical properties of the electrode materials were analyzed. The results showed that the electrode material prepared using KOH as an activator at 700 °C exhibited optimal performance, with a high specific surface area (1480.53 m2·g−1), pore volume (0.943 cm3·g−1), specific capacitance (185.9 F·g−1), and equivalent series resistance (0.73 Ω). The material maintained 97.8% of its specific capacitance after 1000 cycles at a current density of 1 A·g−1 with benign cycle stability. This study confirmed that the production of HA as an electrode material at a low cost with good performance presents significant prospects.

Hierarchically Superstructured Anisotropic Carbon Particles by Multiscale Assembly Driven by Spinodal Decomposition.

Hierarchical superstructures have novel shape-dependent properties, but well-defined anisotropic carbon superstructures with controllable size, shape, and building block dimensionality have rarely been accomplished thus far. Here, a hierarchical assembly technique is presented that uses spinodal decomposition (SD) to synthesize anisotropic oblate particles of mesoporous carbon superstructure (o-MCS) with nanorod arrays by integrating block-copolymer (BCP) self-assembly and polymer-polymer interface behaviors in binary blends. The interaction of major and minor phases in binary polymer blends leads to the formation of an anisotropic oblate particle, and the BCP-rich phase enables ordered packing and unidirectional alignment of carbon nanorods. Consequently, this approach enables precise control over particles' size, shape, and over the dimensionality of their components. Exploiting this functional superstructure, o-MCS are used as an anode material in potassium-ion batteries, and achieve a notable specific capacity of 156mAhg-1 at a current density of 2Ag-1, and long-term stability for 3000 cycles. This work presents a significant advancement in the field of hierarchical superstructures, providing a promising strategy for the design and synthesis of anisotropic carbon materials with controlled properties, offering promising applications in energy storage and beyond.

Ultraviolet light–assisted synthesis of nanostructured carbon materials for supercapacitor electrodes by using zinc oxide structures as template and catalyst

Ultraviolet light–assisted synthesis of nanostructured carbon materials for supercapacitor electrodes by using zinc oxide structures as template and catalyst

One-step green synthesis of N-doped hierarchical porous carbon from glycine for high-performance symmetric supercapacitor

N-doped hierarchical porous carbon (NHPC) was facilely fabricated by a one-step pyrolysis of glycine and water-soluble Na2CO3, which is employed as a renewable water-soluble template without additional corrosive activating reagent. Benefiting from the hierarchical porous structure, high specific surface area (2735 m2 g−1) and the suitable nitrogen content of 3.84 at%, the obtained porous carbon exhibits a high specific capacitance (Csp) of 267 F g−1 at 0.2 A g−1 in a three-electrode system and 201 F g−1 at 0.2 A g−1 in the symmetric supercapacitor. More importantly, it shows an impressive rate capability of 102 % retention at 20 A g−1, outstanding cycling stability with 99.95 % of capacitance retention at 5 A g−1 after 10,000 cycles and a high energy density of 28.8 Wh kg−1 at a power density of 20 KW kg−1 in the symmetric supercapacitor. The results indicate that the synthesized NHPC obtained from this simple synthesis method would be an effective electrode material for symmetric supercapacitors, and this eco-friendly and easily scaled-up approach would provide a valuable strategy for the synthesis of porous carbon materials.