Facile One-step Carbonization Research Articles

Conversion of 5-hydroxymethylfurfural and carbohydrates to 5-ethoxymethylfurfural over chitin-derived solid acid catalysts

The use of environment friendly biomass-based catalysts in bio refinery is highly desirable. In this paper, the preparation of sulfonated carbon materials from biopolymers (typically chitin and cellulose) via facile one-step carbonization and sulfonation using p-toluenesulfonic acid as sulfonating agent was demonstrated. Unlike nitrogen-free cellulose, the basic nitrogen-containing sites generated from chitin decreased the acidity strength of the catalysts, which was confirmed by the results of 31P Nuclear Magnetic Resonance (31P NMR). The suppressed acidity strength boosted the selectivity of 5-ethoxymethylfurfural (EMF) from 5-hydroxymethylfurfural (HMF) by inhibiting the formation of by-products, such as ethyl levulinate (EL) and humins. An 84.3 % yield of EMF from HMF was obtained over the as-prepared chitin-derived solid acid. The catalyst could be reused at least three times without obvious decrease of catalytic activity. Moreover, 74.6 %, 31.9 % and 60.7 % yields of EMF were obtained from fructose, sucrose and inulin in ethanol-containing solvents, respectively. This work offers an example for the synthesis of biofuels using biomass-derived catalysts.

Low-cost and broadband microwave absorption materials derived from carbonized papers

Low-cost microwave absorption materials with broad bandwidth are highly attractive in practical applications. Herein, three kinds of low-cost biomass papers, that are printer paper, toilet paper and newspaper, have been utilized to fabricate microwave absorbers by a facile one-step carbonization method. These three kinds of carbonized papers show potentials in microwave absorption, where the carbonized toilet paper (CTP) exhibits the best performance. It is found that the fibers in CTP exhibits a helix-like morphology with loose and porous state, which would be beneficial to induce the unique cross-polarization loss for the chiral materials and multiple scatting of microwave. Besides, a hybrid structure of polycrystalline-amorphous carbon is formed in the fibers by controlling the carbonization temperature, which would increase the interfacial polarization and tune the conductivity that leads to a good impedance matching. Consequently, the minimum reflection loss of CTP reaches −47 dB at 18.0 GHz with a thickness of only 2.0 mm. Meanwhile, CTP also exhibits as wide as 7.2 GHz effective absorption bandwidth at a thickness of 2.5 mm. This study provides a useful guidance for recycling the biomass materials to design and prepare low-cost and broadband microwave absorbers.

Biomass-Derived Carbon Dots as Nanoprobes for Smartphone-Paper-Based Assay of Iron and Bioimaging Application.

A facile one-step carbonization approach is reported herein for the sustainable hydrothermal synthesis of fluorescent blue nitrogen-doped carbon quantum dots (NCQDs) using banana petioles obtained as biomass waste. These NCQDs were used to design a "turn-off" fluorescent probe, which exhibited excellent sensing capability toward the selective detection of micronutrient, Fe3+ ion, with a limit of detection (LOD) of 0.21 nM. The turn-off process involves the formation of a nonradiative charge transfer complex via a photoinduced electron transfer process. The sensor showed a linear range from 5 to 200 nM and was used for the estimation of Fe3+ ions in real plant samples. Further, a paper-based assay was developed for the quantitative estimation of Fe3+ with LOD values of 0.47 nM for solution-based assay and 0.94 nM for paper-based assay using a smartphone-based readout for potential on-field applications in precision agriculture. Bioimaging studies on banana leaf cells using NCQDs revealed the selective staining of stomata openings on leaf lamella. Therefore, this work provides a way for the valorization of biomass waste into functional nanomaterials without using any extra chemicals.

N-rich doping strategy for constructing Ni@NC catalysts to boost aqueous ethanol coupling towards higher alcohols by inhibiting C1 byproducts

Aqueous coupling of biomass fermentation bio-ethanol offers a promising biorefinery pathway for manufacturing higher alcohols, but it still suffers from the poor utilization efficiency due to the excessive formation of undesired C1 byproducts (CH4, CO and CO2). Herein, N-rich Ni@NC catalysts were synthesized via a facile one-step carbonization of organic–inorganic co-assembly containing polyacrylamide and nickel acetate. Interestingly, the optimized Ni@NC catalyst exhibited excellent performance in aqueous ethanol coupling, giving 74.8 % of ethanol conversion, 49.3 % of C4+ higher alcohol yield and only 1.6 % of C1 gas byproduct selectivity after 12 h reaction at 230 °C. The experimental results and DFT calculations revealed that the regulation of N-rich doping weakened the interaction of Ni with intermediated CH3CHO for inhibiting its deep decomposition into C1 gas byproducts, thereby facilitating the coupling reaction to produce more higher alcohols. Moreover, a feasibility to scale-up the aqueous ethanol coupling was further validated through a 100-fold magnification experiment at ranges of 50–5000 mL, and the fuel properties of higher alcohols as diesel blending were also evaluated. This work opens new avenues for efficient mass-production of higher alcohols via aqueous ethanol coupling.

Trimodal hierarchical porous carbon nanorods enable high-performance Na-Se batteries.

Technical bottlenecks of polyselenide shuttling and material volume variation significantly hamper the development of emerging sodium-selenium (Na-Se) batteries. The nanopore structure of substrate materials is demonstrated to play a vital role in stabilizing Se cathodes and approaching superior Na-ion storage properties. Herein, an ideal nanorod-like trimodal hierarchical porous carbon (THPC) host is fabricated through a facile one-step carbonization method for advanced Na-Se batteries. The THPC possesses a trimodal nanopore structure encompassing micropores, mesopores, and macropores, and functions as a good accommodator of Se molecules, a reservoir of polyselenide intermediates, a buffer for volume expansion of Se species during sodiation, and a promoter for electron/ion transfer in the electrochemical process. As a result, Na-Se batteries assembled with the Se-THPC composite cathode realize high utilization of Se, fast redox kinetics, and excellent cyclability. Furthermore, the Na-ion storage mechanism of the well-designed Se-THPC composite is profoundly revealed by in situ visual characterization techniques.

One-step synthesis of interface-coupled Si@SiOX@C from whole rice-husks for high-performance lithium storage

As the world transitions towards an electric vehicle-driven future, demand for energy storage materials has continued to grow. Silicon-carbon composites are considered one of the most promising anode materials for lithium-ion batteries owing to their superior electrochemical performance. However, their commercialization is seriously limited due to the use of chemical reagents as carbon source, unstable coating structures and the complexity of the synthesis process. Herein, a facile one-step carbonization method at 800 °C was used to prepare Si@SiOX@C-800 composite by using rice husks, 1‑butyl‑3-methylimidazolium acetate (BMIMAcO) and silicon nanoparticles (Si-NPs). When the optimized Si@SiOx@C-800 was applied to the anode of lithium-ion batteries, it exhibited prominent reversible capacity (694 mAh g−1 at 0.1 A g−1), with remarkable rate performance (220 mAh g−1 at 2 A g−1), and excellent cyclic stability (460 mAh g−1 with a capacity retention of 105.7% at 1 A g−1 after 1000 cycles). The coupling of interfaces by Si-N bonds led to the formation of a double-layered structure which enhanced Li+ diffusion coefficients and electrochemical kinetics, while tremendously limiting the volume variation of Si nanoparticles (Si NPs). The double-shell-structured Si@SiOX@C-800 composite material which was facilely synthesized using an eco-friendly approach presented superior electrochemical performance.

Facile synthesis of Fe-modified lignin-based biochar for ultra-fast adsorption of methylene blue: Selective adsorption and mechanism studies

A novel Fe-modified lignin-based biochar (Fe-LB) was fabricated via a facile one-step carbonization method for methylene blue (MB) removal from wastewater. Fe-LB exhibited a high specific surface area (885.97 m2/g) and micropore volume (0.3203 m3/g), and demonstrated high affinity for MB with the maximum adsorption capacity of 2.7-fold by Fe-LB than LB. It was found that quick adsorption could be achieved in 15 min with the MB removal efficiency of 100% and adsorption capacity reached 200 mg/g. Selective adsorption studies indicated that Fe-LB preferentially adsorbed MB in high salt and multiple dye systems (binary, ternary, and quaternary) over a wide pH range from 2 to 12. The removal efficiency of CR was greatly improved due to the synergistic effect between MB and CR in the binary system. This work demonstrated that Fe-LB can effectively remove dye contaminants and possessed great potential in the treatment of MB polluted dye wastewater.

Facile fabrication of N-doped hierarchical porous carbons derived from soft-templated ZIF-8 for enhanced adsorptive removal of tetracycline hydrochloride from water

N-doped hierarchical porous carbons (NHPCs) were successfully prepared from soft-templated zeolitic imidazolate framework-8 (ZIF-8) precursors using sodium dodecylbenzene sulfonate (SDBS) as a template through facile one-step carbonization and applied in tetracycline hydrochloride (TCH) adsorption. The NHPC synthesized at 1000 °C with an SDBS/Zn2+ molar ratio of 0.075 exhibited the highest TCH adsorption (qm = 80.92 mg g−1) owing to its relatively large BET surface area (1067.41 m2 g−1) and pore volume (1.22 cm3 g−1) and the stronger surface interaction between TCH and NHPCs (HC1000–0.075). Compared with surfactant-free ZIF-8-derived carbon (HC), introduction of SDBS in the ZIF-8 precursor not only improved the pore structure of the carbon materials but also increased the nitrogen content and the number of surface functional groups. Adsorption kinetics and isotherms showed that the pseudo-second-order model and Sips model fit the TCH adsorption behavior on HC and HC1000–0.075 well. Adsorption experiments and characterizations revealed that the adsorption mechanism involved in TCH adsorption on HC1000–0.075 mainly depended on the synergistic effect of pore filling, H-bonding, π-π interactions, and weak electrostatic interactions. This study provides an effective and simple strategy for fabricating MOF-derived NHPCs as a promising adsorbent for the removal of antibiotics from water.

The Positive Effect of ZnS in Waste Tire Carbon as Anode for Lithium-Ion Batteries.

There is great demand for high-performance, low-cost electrode materials for anodes of lithium-ion batteries (LIBs). Herein, we report the recovery of carbon materials by treating waste tire rubber via a facile one-step carbonization process. Electrochemical studies revealed that the waste tire carbon anode had a higher reversible capacity than that of commercial graphite and shows the positive effect of ZnS in the waste tire carbon. When used as the anode for LIBs, waste tire carbon shows a high specific capacity of 510.6 mAh·g−1 at 100 mA·g−1 with almost 97% capacity retention after 100 cycles. Even at a high rate of 1 A·g−1, the carbon electrode presents an excellent cyclic capability of 255.1 mAh·g−1 after 3000 cycles. This high-performance carbon material has many potential applications in LIBs and provide an alternative avenue for the recycling of waste tires.

Integration of nickel phosphide nanodot-enriched 3D graphene-like carbon with carbon fibers as self-supported sulfur hosts for advanced lithium sulfur batteries

Lithium-sulfur batteries are spotlighted as the promising next-generation batteries because of their high energy density and low-cost. Nevertheless, intrinsic low conductivity, notorious shuttle effect, and sluggish redox kinetics of sulfur cathode greatly impede their commercialization. Herein, we design and demonstrate a powerful combined strategy to build a novel hybrid architecture for hosting sulfur, which are achieved by growing Ni2P nanodot-enriched 3D graphene-like carbon onto carbon fiber paper (NP-3DGC@CFP) via a facile one-step carbonization approach. In the integrated NP-3DGC@CFP/S electrode: micro-mesoporous 3DGC provides abundant space and complicated pore structures to accommodate sulfur and physically confine polysulfide species; polar Ni2P nanodots chemically immobilize the lithium polysulfides and accelerate electrochemical reaction kinetics; flexible CFP serves as mechanical scaffold to support the electrode and avoids binder-related limitations. As a result, self-supported NP-3DGC@CFP/S cathode demonstrates an excellent combination of capacity, rate, cycling endurance (1409.4 mAh g−1 at 0.1 C, 538.2 mAh g−1 at 5 C, 786.3 mAh g−1 with 72.7% retention at 0.5 C for 300 cycles) and anti-self-discharge capability. Significantly, such cathode also shows satisfied cycling stability at a high sulfur loading of 6.5 mg cm−2 or at a high rate of 2 C, demonstrating its bright perspective for practical application.

Biomass derived hierarchical porous carbon for high-performance O2/N2 adsorption; a new green self-activation approach.

Biomass-derived porous carbons are the most common adsorbent materials for O2/N2 adsorption because of their excellent textural properties, high surface area, and low expense. A new synthesis method based on a self-activation technique was developed for a new green porous carbon adsorbent. This ecofriendly system was used for the synthesis of hierarchical porous carbons from walnut-shell precursors. The sorbent was successfully synthesized by facile one-step carbonization, with the activating reagents being gases released during the activation. The sample morphology and structure were characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, X-ray powder diffraction, thermogravimetric, and differential thermal analysis. The optimal porous carbons were synthesized at 1000 °C, providing a surface area as high as 2042.4 (m2 g−1) and micropore volume of about 0.499 (m3 g−1). At 298 °K under 9.5 bar pressure, the potential for O2/N2 separation using porous carbon samples was studied, and the sips isotherms with the highest adsorption potential were determined to be 2.94 (mmol g−1) and 2.67 (mmol g−1), respectively. The sample exhibited stable O2/N2 separation over ten cycles, showing high reusability for air separation. Finally, the technology described presents a promising strategy for producing eco-friendly porous carbon from a variety of biomass on an industrial scale.

One-step synthesis of nitrogen, sulfur co-doped interconnected porous carbon derived from methylene blue for high-performance supercapacitors

In this work, nitrogen (N), sulfur (S) co-doped porous carbon nanoplate (A-MBCP) is successfully prepared from methylene blue (MB) by facile one-step carbonization and activation strategy. It is an efficient method to protect the environment and meet industrialization production. The obtained carbon nanoplate exhibits in-situ doping of N, S, high specific surface area (560.46 m2 g−1), interconnected and hierarchical porous morphology, together with large interlayer spacing. This unique and complex micromorphology endows the A-MBCP electrode with superior electrochemical performance, including ultra-high specific capacitance of 302 F g−1 at 0.5 A g−1 and excellent capacitance retention of 77.82% at 10 A g−1 in 6 M KOH electrolyte. Furthermore, the assembled A-MBCP//A-MBCP symmetric supercapacitor displays outstanding energy density of 25 Wh kg−1 and power density of 8000 W kg−1 using Na2SO4 as electrolyte. Also, the high capacitance retention of 98.6% and coulombic efficiency of 97.9% are achieved for the supercapacitor after 3000 cycles at 2 A g−1 in KOH electrolyte, implying its favorable electrochemical stability and charge/discharge reversibility. This novel preparation of high-performance supercapacitors from MB may further inspire the development of other carbon materials with heteroatoms doping applied in the energy storage application.

High-performance supercapacitors enabled by boron/nitrogen co-doped carbons through WPU/PF/GO composite

In this study, a facile one-step carbonization was developed for producing B and N co-doped carbon through waterborne polyurethane, phenolic resin, and graphene oxide composite (nWPGC) used as electrode materials in supercapacitors. Furthermore, nitrogen-enriched carbon also had repetitive urethane bond (-NHCOO) in waterborne polyurethane (nWPU). Moreover, we used the ferric chloride treatment and washing method to remove the B–N bonds. The fabricated B/N co-doped carbon had a high specific capacitance of 356.3 F g−1 at 0.5 A g−1 in 6 M KOH electrolyte, with the surface area, and pore volume (611 m2 g−1 and 0.3 cm3 g−1). The assembled nWPGC-Fe-B//nWPGC-Fe-B symmetric supercapacitor exhibited an energy density of 10.35 Wh kg−1 was achieved at a power density of 493.2 W kg−1. On top of that, the capacitor also maintained a well rate capability and brilliant cyclic stability of 89.78% capacitance retention even after 5000 cycles.

Carbon foam with microporous structure for high performance symmetric potassium dual-ion capacitor

Abstract A novel carbon foam with microporous structure (CFMS), with the advantages of a simple fabrication process, low energy consumption, large specific surface area and high conductivity, has been prepared by a facile one-step carbonization. In addition, the carbon foam possesses suitable interlayer spacing in short range which is flexible to accommodate the deformation of carbon layer caused by the ion insertion and deinsertion at the charge and discharge state. Furthermore, a low cost carbon-based symmetric potassium dual-ion capacitor (PDIC), which integrates the virtues of potassium ion capacitors and dual-ion batteries, is successfully established with CFMS as both the battery-type cathode and the capacitor-type anode. PDIC displays a superior rate performance, an ultra-long cycle life (90% retention after 10000 cycles), and a high power density of 7800 W kg−1 at an energy density of 39 Wh kg−1. The PDIC also exhibits excellent ultrafast charge and slow discharge properties, with a full charge in just 60 s and a discharge time of more than 3000 s.

Superior acetone uptake of hierarchically N-doped potassium citrate-based porous carbon prepared by one-step carbonization

A novel hierarchically N-doped porous carbon material (NP) has been prepared using potassium citrate as the carbon source and urea as the nitrogen source by a facile one-step carbonization method. The resulting NP materials possess two important characteristics: (1) They have abundant nitrogen contents (up to 11.03%) and (2) they exhibit, in relation to porous carbon without urea doping (narrow micropore size), a wider mesopore size. The NP materials exhibit an excellent acetone adsorption capacity; a highest value of 1058 mg g−1 (15 °C) was provided by carbon material prepared in the case of urea/potassium citrate = 1 and 800 °C, which is 158.6% higher than that of the N-free material. The total pore volume, especially the mesoporous volume, was the key factor to determine acetone adsorption under relative high pressure due to the presence of a multilayer adsorption based on adsorption isotherm models. Meanwhile, nitrogen functional groups promoted adsorption process at relative low pressure, and density functional theory results further confirm nitrogen-containing functional groups enhance adsorption interaction between carbon surface and acetone molecule through the hydrogen bonding interaction. This study paves a new way to develop a novel hierarchically N-doped porous carbon with controllable well-developed porosity for the adsorption applications.

Boron/Nitrogen/Oxygen Co-Doped Carbon with High Volumetric Performance for Aqueous Symmetric Supercapacitors

From the practical application of supercapacitors, the development of carbon materials with high volumetric performance is highly desired. We report the synthesis of B/N/O co-doped carbon by a facile one-step carbonization method of polyvinylpyrrolidone/melamine formaldehyde resin with boric acid/urea treatment and a subsequent washing process. It is shown that a boric acid/urea treatment is an effective approach to incorporating B into N/O enriched carbon and effectively restraining the generation of inert B-O and B-N species. Moreover, a boric acid/urea treatment and washing process can increase specific surface area, optimize pore structure, and retain many active heteroatoms without lowering density, contributing to good conductivity, fast charge transfer and electrolyte ion diffusion, and high volumetric performance. The fabricated B/N/O co-doped carbon shows high active heteroatoms of 8.69 at.% (N-5, N-6, B-C and O-I), moderate surface area, and pore volume (778.02 m2 g−1 and 0.341 cm3 g−1), high density (1.3 g cm−3), high specific volumetric, and gravimetric capacitances (309 F cm−3 and 238 F g−1 at 0.5 A g−1) and superior cycling stability. The assembled symmetric supercapacitor delivers relatively high volumetric energy density (11.5 Wh L−1 at 622 W L−1) in 6 M KOH electrolyte. The B/N/O co-doped carbon has great potential for applications in supercapacitors.

In-suit Mg(OH)2 template synthesis of nitrogen-doped porous carbon materials from glutinous rice for supercapacitors with excellent electrochemical performance

In the present study, a new biomass-derived multilayer graphene-like low dimensional carbon material was prepared through the facile one-step carbonization of glutinous rice without conventional KOH chemical activation at 900 °C in an argon atmosphere. The formation of disordered microporous and mesoporous on carbon, the high specific surface area of 1,371.50 m2 g−1, and the pore volume of 2.351 cm3 g−1 were confirmed by N2 adsorption and desorption. As a merit of its favorable structural features, the graphene-like carbon electrode exhibits an enhanced electric double layer capacitance (high specific capacitance of 289.9 F g−1 and 174 F g−1 at 0.5 A g−1 and 10 A g−1) and excellent cycling stability of 88% after 20,000 cycles at a current density of 8 A g−1. This observed electrochemical performance clearly indicates that activated carbon derived from glutinous rice could be used as a promising electrode material in a supercapacitor for electrochemical energy storage.

Enhanced Lithium- and Sodium-Ion Storage in an Interconnected Carbon Network Comprising Electronegative Fluorine.

Fluorocarbon (CxFy) anode materials were developed for lithium- and sodium-ion batteries through a facile one-step carbonization of a single precursor, polyvinylidene fluoride (PVDF). Interconnected carbon network structures were produced with doped fluorine in high-temperature carbonization at 500-800 °C. The fluorocarbon anodes derived from the PVDF precursor showed higher reversible discharge capacities of 735 mAh g-1 and 269 mAh g-1 in lithium- and sodium-ion batteries, respectively, compared to the commercial graphitic carbon. After 100 charge/discharge cycles, the fluorocarbon showed retentions of 91.3% and 97.5% in lithium (at 1C) and sodium (at 200 mA g-1) intercalation systems, respectively. The effects of carbonization temperature on the electrochemical properties of alkali metal ion storage were thoroughly investigated and documented. The specific capacities in lithium- and sodium-ion batteries were dependent on the fluorine content, indicating that the highly electronegative fluorine facilitates the insertion/extraction of lithium and sodium ions in rechargeable batteries.

Low-Cost and High-Performance Hard Carbon Anode Materials for Sodium-Ion Batteries.

As an anode material for sodium-ion batteries (SIBs), hard carbon (HC) presents high specific capacity and favorable cycling performance. However, high cost and low initial Coulombic efficiency (ICE) of HC seriously limit its future commercialization for SIBs. A typical biowaste, mangosteen shell was selected as a precursor to prepare low-cost and high-performance HC via a facile one-step carbonization method, and the influence of different heat treatments on the morphologies, microstructures, and electrochemical performances was investigated systematically. The microstructure evolution studied using X-ray diffraction, Raman, Brunauer–Emmett–Teller, and high-resolution transmission electron microscopy, along with electrochemical measurements, reveals the optimal carbonization condition of the mangosteen shell: HC carbonized at 1500 °C for 2 h delivers the highest reversible capacity of ∼330 mA h g–1 at a current density of 20 mA g–1, a capacity retention of ∼98% after 100 cycles, and an ICE of ∼83%. Additionally, the sodium-ion storage behavior of HC is deeply analyzed using galvanostatic intermittent titration and cyclic voltammetry technologies.

Flower-like hierarchical porous nitrogen-doped carbon spheres from a facile one-step carbonization method for supercapacitors

A facile one-step carbonization method was developed to fabricate flower-like hierarchical porous nitrogen-doped carbon sphere (FHPNCS) from polyimide using polyurethane foam as macroporous scaffold. The FHPNCS possessed flower-like spherical morphology, well-developed hierarchical porous structure, high specific surface area and nitrogen-containing functional groups. These advantages led to excellent electrochemical performance. The FHPNCS electrode exhibited a high specific capacitance of 251.6 F g−1 at 1 A g−1, a high rate capability of 76% capacitance retention at 5 A g−1, and an outstanding cycling stability of only 4.4% loss in specific capacitance after 2000 cycles. Compared with previously reported multi-step templating methods, the present method only involves a facile thermal treatment procedure and avoids the use of hard templates and toxic raw materials, thus exhibiting great potential for large scale production of nitrogen-doped carbon materials for practical applications in supercapacitors.