Cellulose-based Carbon Research Articles

Converting large-scale waste paper fibers into lanthanum-modified cellulose carbon aerogel adsorbents for efficient phosphorus removal

This study presents the synthesis of a novel lanthanum-modified cellulose-based carbon aerogel (La-CCA) from waste printing paper, aimed at addressing the issue of phosphate pollution in aquatic environments. The objective was to develop an effective and sustainable adsorbent to mitigate eutrophication caused by excess phosphates in water bodies. La-CCA exhibited a remarkable phosphate adsorption capacity, peaking at 44.32 mg/g under optimal conditions, demonstrating its efficiency as an adsorbent. The novelty of this work lies in the use of waste paper as a raw material, coupled with lanthanum modification, which enhanced adsorption performance through multiple mechanisms, including electrostatic interactions, ligand exchange, and inner-sphere complexation. The study also discussed the retention of the microfibrous structure of cellulose, contributing to the material’s stability and functionality. Comprehensive analyses including zeta potential, FTIR, and XPS elucidate the underlying adsorption mechanisms. La-CCA was demonstrated to be easily separable from solutions with minimal lanthanum leaching, particularly under conditions above pH 3.0, underscoring its potential for practical applications in phosphate removal from nutrient-enriched waters.

Kapok/regenerated cellulose based carbon aerogel prepared at a low-temperature carbonization for oil/water separation

With the requirement of sustainable development in modern society, selective filtration and separation of oils and organic solvents from polluted wastewater is a critical and very important goal. Herein, a novel hydrophobic and oleophilic cellulose-based carbon aerogel composed of kapok fiber/regenerated cellulose was prepared at a low-temperature carbonization technique (300 ℃) directly using kapok and hardwood pulp as raw material, the N-methyl N-oxide monohydrate (NMMO·H2O) as a green cellulose solvent, and NH4H2PO4 (ADP) as a carbonization promotor, which is denoted as AX-KRCA(AX: A indicates the ADP used, x is the concentration of ADP solution (g/L)) The regenerated cellulose (RC) was converted from hardwood pulp via NMMO·H2O treatment, and further combined with kapok fiber to form a 3D porous structure. By adding ADP, AX-KRCA can be rapidly dehydrated into carbon at 300 ℃, which not only saves energy consumption but also retains the basic form of kapok fiber and regenerated cellulose, making it have excellent compressibility, elasticity, and fatigue resistance. The ultra-light porous AX-KRCA samples can be an efficient oil/water adsorbent, with an adsorption capacity from 98.0 to 232.1 g g−1 for various oils, and can maintain 87.3 % adsorption capacity after 20 cycles and 99.6 % separation efficiency after 5 times of filtration.

High-performance cellulose-based nanostructured carbons for rechargeable batteries

Binder-free, highly porous carbon nanofibers (CNFs) with novel sponge-like pore structures were synthesized for the first time via centrifugal spinning of cellulose-based polymers, and SnO2 was introduced to improve the electrochemical performance. Cellulose-based binder-free centrifugally spun carbon-coated SnO2/carbon nanofibers (C@SnO2/CNFs) were employed as anodes in Na-ion batteries. Owing to their highly porous morphology with novel sponge-like pore structures and SnO2 nanoparticles providing rapid Na-ion transport, better electrolyte accessibility, and good mechanical strength, the C@SnO2/CNFs showed outstanding electrochemical performance, with a high reversible capacity of 660 mAh/g at 50 mA/g, high rate capability, and excellent cycling performance. The specific capacity of C@SnO2/CNFs was approximately 390 mAh/g after 2000 cycles at 0.2 A/g. These results prove that the combination of centrifugal spinning, carbon coating, and heat treatment is a promising and sustainable approach for creating cellulose-based carbon nanostructures with highly porous structures that can be used to synthesize high-performance electrodes for energy storage systems.

One-Pot Synthesis of Cellulose-Based Carbon Aerogel Loaded with TiO2 and g-C3N4 and Its Photocatalytic Degradation of Rhodamine B.

A cellulose-based carbon aerogel (CTN) loaded with titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) was prepared using sol-gel, freeze-drying, and high-temperature carbonization methods. The formation of the sol-gel was carried out through a one-pot method using refining papermaking pulp, tetrabutyl titanate, and urea as raw materials and hectorite as a cross-linking and reinforcing agent. Due to the cross-linking ability of hectorite, the carbonized aerogel maintained a porous structure and had a large specific surface area with low density (0.0209 g/cm3). The analysis of XRD, XPS, and Raman spectra revealed that the titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) were uniformly distributed in the CTN, while TEM and SEM observations demonstrated the uniformly distributed three-dimensional porous structure of CTN. The photocatalytic activity of the CTN was determined according to its ability to degrade rhodamine B. The removal rate reached 89% under visible light after 120 min. In addition, the CTN was still stable after five reuse cycles. The proposed catalyst exhibits excellent photocatalytic performance under visible light conditions.

Highly Porous Cellulose-Based Carbon Fibers as Effective Adsorbents for Chlorpyrifos Removal: Insights and Applications

The extensive utilization of the organophosphate pesticide chlorpyrifos, combined with its acute neurotoxicity, necessitates the development of effective strategies for its environmental removal. While numerous methods have been explored for chlorpyrifos removal from water, adsorption is the most promising. We investigated the potential of two cellulose-derived porous carbons as adsorbents for chlorpyrifos removal from water, prepared by either CO2 or H2O activation, resulting in similar morphologies and porosities but different amounts of heteroatom functionalities. The kinetics of batch adsorption removal from water fits well with the pseudo-first-order and pseudo-second-order kinetic models for both materials. The Freundlich, Langmuir, Dubinin–Radushkevich, and Sips isotherm models described the process of chlorpyrifos adsorption very well in all investigated cases. The maximum adsorption capacity determined from the Sips isotherm model gave values of 80.8 ± 0.1 mg g−1 and 132 ± 3 mg g−1 for the H2O and CO2 activated samples, respectively, reflecting the samples’ differences in heteroatom functionalities. Additionally, the application of either adsorbent led to reduced toxicity levels in all tested samples, implying that no harmful by-products were generated during adsorption. Comparative analysis with the existing literature further validates the study’s findings, suggesting the efficacy and applicability of cellulose-based porous carbons for sustainable chlorpyrifos remediation.

Elucidating the enduring transformations in cellulose-based carbon nanofibers through prolonged isothermal treatment

This study investigates the conversion of highly acetylated sugarcane bagasse into high-modulus carbon nanofibers (CnNFs) with exceptional electrical conductivity. By electrospinning the bagasse into nanofibers with diameters ranging from 80 nm to 800 nm, a cost-effective CnNFs precursor is obtained. The study reveals the transformation of the cellulose crystalline structure into a stable antiparallel chain arrangement of cellulose II following prolonged isothermal treatment, leading to a remarkable 50 % increase in CnNFs recovery with carbon contents ranging from 80 % to 90 %. This surpasses the performance of any other reported biomass precursors. Furthermore, graphitization-induced shrinkage of CnNFs diameter results in significant growth of specific surface area and pore volume in the resulting samples. This, along with a highly ordered nanostructure and high crystallinity degree, contributes to an impressive tensile modulus of 9.592 GPa, surpassing that of most petroleum-based CnNFs documented in the literature. Additionally, the prolonged isothermal treatment influences the d002 value (measured at 0.414 nm) and CnNFs degree of crystallinity, leading to an enhancement in electrical conductivity. However, the study observes no size effect advantages on mechanical properties and electrical conductivity, possibly attributed to the potential presence of point defects in the ultrathin CnNFs. Overall, this research opens a promising and cost-effective pathway for converting sugarcane biomasses into high-modulus carbon nanofibers with outstanding electrical conductivity. These findings hold significant implications for the development of sustainable and high-performance materials for various applications, including electronics, energy storage, and composite reinforcement.

Enhanced hydrogen storage and CO2 capture capacities on carbon aerogels from Ni-N co-doping

Carbon aerogels (CAs) has been a promising candidate for gas adsorption due to their unique attributes, but the poor surface properties and temperature reliance limit the application range. Investigations have proven that surface modification can enhance the adsorption performance. Thus, nickel and nitrogen co-doped cellulose-based carbon aerogels were synthesized by introducing nanoparticles. The outcomes demonstrate the excellent adsorption capacity and reversible adsorption/desorption features. Nickel particles improved the dissociation of hydrogen by “hydrogen spillover” effect, and interacted electrostatically with CO2 enhanced the capture performance. Nitrogen particles enhanced the unsaturation of Ni active sites and the surface basicity, resulting a stronger interaction force with adsorbed gases. Ultimately, despite a slightly decrease in specific surface area and micropore volume, the sample exhibit the hydrogen storage capacity of 0.79 wt.% (298 K) and 7.4 wt.% (77 K), and the CO2 capture of 17.1 mmol/g (298 K). Unique design strategy of co-doping reduced the reliance on surface area and temperature changes, and is expected to be a regular means of industrial modification of carbon materials.

A novel cost-effective kapok fibers and regenerated cellulose-based carbon aerogel for continuous oil/water separation

The development of cost-effective, environmentally friendly, and reusable superabsorbent materials for removing oil spills from water presents significant challenges. Herein, a novel, cost-effective, environmentally friendly, and reusable carbon aerogel (KRxCA) was synthesized by combining kapok fibers (KF) with hardwood pulp regenerated cellulose, dissolving in a mixture of N-methyl morpholine-N-oxide monohydrate (NMMO) and deep eutectic solvent (DES), which is named co-solvent DNS. This carbon aerogel presents remarkable compressibility, elasticity, and fatigue resistance, maintaining maximum stress after 100 cycles at 50 % strain due to its three-dimensional network of carbonized hollow tubular KF fixed by carbonized regenerated cellulose. The water contact angle (144.7°) indicates the excellent hydrophobicity of the KR10CA, demonstrating the potential for efficient oil/water separation. The resulting ultra-light (3.78 mg cm−3) and high porous (98.9 %) KR10CA exhibits exceptional oil sorption capacity (137.5–371.7 g⋅g−1) and retains 89.3 % of its sorption capacity after ten extrusion cycles. Additionally, as a filter membrane, the KR10CA effectively separates n-hexane from water with a high flux rate (21972.7 L m-2h−1). Therefore, the carbon aerogel derived from renewable resources presents itself as a cost-effective and environmentally friendly oil/water separator for practical application.

Oxygen-enriched carbon molecular sieve hollow fiber membrane for efficient CO2 removal from natural gas

Natural gas is considered one of the most attractive low carbon energy sources while the separation of CO2 is a crucial process for the natural gas purification. Herein, cellulose-based carbon molecular sieve (CMS) hollow fiber membranes with high CO2 affinity capability were fabricated through a post-treatment strategy of hydrogen-induced reduction followed by oxygen-doped modification (H-O treatment), and show good potential for high pressure natural gas purification. The CMS membranes were reduced by H2 at high temperatures (500–600 °C) to form active sorption sites in the carbon matrix, and subsequently chemically absorbed O2 to generate oxygen-containing functional groups, which are favorable for CO2 adsorption and diffusion. After being treated at 600 °C (CMS-600), the CMS membrane presented a high CO2 adsorption capacity of 62.78 cm3/g (298 K). As a result, the CO2 permeability was enhanced from 264 to 1125 Barrer, with approximately 400 % improvement. Moreover, mixed gas separation performances (CO2/N2 and CO2/CH4) were investigated at high pressure and impurities feedings. The CMS membrane exhibited a remarkable CO2/CH4 separation factor of 104 when operated at 20 bar and 500 ppm heptane existed.

Decoration on the inner surface of low-tortuosity microchannels derived from wood plate for highly stable lithium sulfur batteries

The low-tortuosity microchannels of wood-based carbon matrix in free-standing cathodes for lithium sulfur batteries (LSBs) were a double-edged sword, which brought in both a high energy density due to a high sulfur loading and severe shuttle effect for poor cycling stability. Herein, a layer of cellulose aerogel extracted from the wood wall was coated on the inner surface of the low-tortuosity microchannels of the wood plate, which was further transformed into a hierarchical carbon matrix using in free-standing cathode for LSBs. The decorated cathode exhibited a maximal specific capacity of 1377.2 mAh g−1 due to the enhanced utilizing ratio of active materials and exceptional cycling stability even under a high current density (1 C) for more than 500 cycles. Furthermore, the decorated cathode maintained good cycling stability with a higher sulfur areal loading (6.3 mg cm−2). The cellulose-based carbon aerogel coated on the inner surface of low-tortuosity microchannels provided a large specific surface area. This decoration strategy not only provided physical restriction on polysulfides but also increased conversion sites for polysulfides, improving the cycling performance of the wood-based free-standing cathode of LSBs. This work provided a potential structural design strategy for the advanced free-standing cathode of LSBs.

Characterization of Activated Sodium Carboxymethyl Cellulose-based Carbon Foams Containing Expanded Graphites as High Performance Supercapacitor Electrodes

Characterization of Activated Sodium Carboxymethyl Cellulose-based Carbon Foams Containing Expanded Graphites as High Performance Supercapacitor Electrodes

Utilization of cellulose-based carbon nanodots in sulfonated polysulfone based membrane for direct methanol fuel cell

Sulfonated polysulfone (SPS) composite membranes consisting of cellulose-based carbon nanodots (CNDs) were successfully prepared as a proton exchange membrane (PEM) for direct methanol fuel cell (DMFC) applications. The CNDs were prepared using the top-down hydrothermal method. The structure transformation from cellulose to CNDs was confirmed by the FTIR and XRD analysis. The particle size of CNDs was between 1 and 3 nm. The particles exhibited good optical properties. The incorporation of CND into matrix polymer increased the thermal stability of the membranes. Morphology analysis of the SPS/CND composite membranes revealed that CNDs had been successfully dispersed within the SPS polymer matrix. The cross-linking between SPS and CNDs enhanced the proton conductivity of the composite membranes compared to the pristine SPS membrane. The SPS/CND-1 (1 wt%) exhibited the highest selectivity with a proton conductivity of 35.5 mS.cm−1 and a methanol permeability of 3.50 × 10−6 cm2.s−1. The experimental results indicate that the incorporation of CNDs into the SPS membrane also decreased the amount of methanol that can pass through the membrane when used in DMFCs.

Hierarchically porous cellulose-based carbon aerogels with N-doped skeletons and encapsulated iron-based catalysts for efficient tetracycline catalytic degradation

Three-dimensional interpenetrating and hierarchically porous carbon material is an efficient catalyst support in water remediation and it is still a daunting challenge to establish the relationship between hierarchically porous structure and catalytic degradation performance. Herein, a highly porous silica (SiO2)/cellulose-based carbon aerogel with iron-based catalyst (FexOy) was fabricated by in-situ synthesis, freeze-drying and pyrolysis, where the addition of SiO2 induced the hierarchically porous morphology and three-dimensional interpenetrating sheet-like network with nitrogen doping. The destruction of cellulose crystalline structure by SiO2 and the iron-catalyzed breakdown of glycosidic bonds synergistically facilitated the formation of electron-rich graphite-like carbon skeleton. The unique microstructure is confirmed to be favorable for the diffusion of reactants and electron transport during catalytic process, thus boosting the catalytic degradation performance of carbon aerogels. As a result, the catalytic degradation efficiency of tetracycline under light irradiation by adding only 5 mg of FexOy/SiO2 cellulose carbon aerogels was as high as 90 % within 60 min, demonstrating the synergistic effect of photocatalysis and Fenton reaction. This ingenious structure design provides new insight into the relationship between hierarchically porous structure of carbon aerogels and their catalytic degradation performance, and opens a new avenue to develop cellulose-based carbon aerogel catalysts with efficient catalytic performance.

Cellulose-based carbon nanotubes array with lawn-like 3D architecture for oxygen reduction reaction

The conversion of biomass into high-performance carbon-based materials provides an opportunity to valorize biomass for advanced applications. Achieving this necessitates requires dedicated efforts and innovations in biocarbon synthesis, design, and applications. This study proposes the controllable conversion of biomass-derived cellulose into well-distributed carbon nanotubes (CNTs) by tuning the precipitation of cellulose pyrolysis generated vapors with in-situ formed ferric metal nanoparticles. The obtained CNTs exhibited lawn-like 3D architecture with similar length, uniform alignment, and dense distribution. The combined use of ferric chloride and dicyandiamide as the reagents with a mass ration of 0.162:1.05, demonstrated optimal performance in controlling the morphology of CNTs, enhancing the graphitization, and increasing the content of graphitic-N and pyridine-N. This multi-dimensional modification enhanced the electrocatalytic performance of the obtained CNTs, achieving an onset potential of 0.875 V vs. relative hydrogen electrode (RHE), a half-wave potential of 0.703 V vs. RHE, and a current density of −4.95 mA cm−2 during the oxygen reduction reaction. Following microbial fuel cells (MFCs) tests achieved an output voltage of 0.537 V and an output power density of 412.85 mW m−2, comparable to MFC with Pt/C as the cathode catalyst. This biomass-derived catalyst is recommended as a high-quality, non-noble metal alternative to traditional noble-metal catalysts.

Regulating oxygen functionalities of cellulose-derived hard carbon toward superior sodium storage

A pre-oxidation treatment was applied to adjust the microstructure of hard carbon; we investigated the mechanism of pre-oxidation, designed a closed-pore structure and constructed a high plateau capacity anode for sodium-ion batteries.

Zinc Oxide-Loaded Cellulose-Based Carbon Gas Sensor for Selective Detection of Ammonia.

Cellulose-based carbon (CBC) is widely known for its porous structure and high specific surface area and is liable to adsorb gas molecules and macromolecular pollutants. However, the application of CBC in gas sensing has been little studied. In this paper, a ZnO/CBC heterojunction was formed by means of simple co-precipitation and high-temperature carbonization. As a new ammonia sensor, the prepared ZnO/CBC sensor can detect ammonia that the previous pure ZnO ammonia sensor cannot at room temperature. It has a great gas sensing response, stability, and selectivity to an ammonia concentration of 200 ppm. This study provides a new idea for the design and synthesis of biomass carbon-metal oxide composites.

High-performance hydrogen separation using cellulose-based carbon molecular sieve membranes

Cellulose-based carbon molecular sieve membranes were designed for hydrogen deblending from natural gas and hydrogen recovery from other relevant industrial sources. The crystallinity of the cellulose precursor was increased by adding propylene glycol, which originated a carbon membrane with a permeability to the hydrogen of 544 barrer and an H2/CH4 permselectivity of ca. 3500 (Robeson index = 100). A careful optimization of the carbonization conditions of the cellulose precursor boosted the carbon membrane permeability to hydrogen to 1144 barrer and the H2/CH4 permselectivity to 1080 (Robeson index = 62). The membrane with the highest permeability to hydrogen presented the highest micropore volume of 0.443 cm3·g−1 and a micropore surface area of 1326 m2·g−1.A detailed techno-economic analysis of the hydrogen recovery from the natural gas was performed. It was concluded that a single-stage carbon membrane module can recover hydrogen with a concentration of 99.8 % and a specific cost of 0.26 €·kgH2−1 for a hydrogen recovery of 68 %. A two-stage membrane process was simulated to deliver a purity >99.997 % and a recovery of 96 %, with a specific cost of 1.8 €·kgH2−1. The carbon membranes prepared in this work are highly competitive with other separation processes for the recovery and purification of hydrogen from different industrial processes essential for the decarbonization.

Boric Acid as A Low-Temperature Graphitization Aid and Its Impact on Structure and Properties of Cellulose-Based Carbon Fibers.

In the present paper, a scalable, economically feasible, and continuous process for making cellulose-based carbon fibers (CFs) is described encompassing precursor spinning, precursor additivation, thermal stabilization, and carbonization. By the use of boric acid (BA) as an additive, the main drawback of cellulose-based CFs, i.e., the low carbon yield, is overcome while maintaining a high level of mechanical properties. This is demonstrated by a systematic comparison between CFs obtained from a BA-doped and an un-doped cellulose precursor within a temperature range for carbonization between 1000 and 2000 °C. The changes in chemical composition (via elemental analysis) and physical structure (via X-ray scattering) as well as the mechanical and electrical properties of the resulting CFs were investigated. It turned out that, in contrast to current opinion, the catalytic effect of boron in the formation of graphite-like structures sets in already at 1000 °C. It becomes more and more effective with increasing temperature. The catalytic effect of boron significantly affects crystallite sizes (La, Lc), lattice plane spacings (d002), and orientation of the crystallites. Using BA, the carbon yield increased by 71%, Young's modulus by 27%, and conductivity by 168%, reaching 135,000 S/m. At the same time, a moderate decrease in tensile strength by 25% and an increase in density of 14% are observed.

Interdependent factors influencing the carbon yield, structure, and CO_{2} adsorption capacity of lignocellulose-derived carbon fibers using multiple linear regression

Cellulose has experienced a renaissance as a precursor for carbon fibers (CFs). However, cellulose possesses intrinsic challenges as precursor substrate such as typically low carbon yield. This study examines the interplay of strategies to increase the carbonization yield of (ligno-) cellulosic fibers manufactured via a coagulation process. Using Design of Experiments, this article assesses the individual and combined effects of diammonium hydrogen phosphate (DAP), lignin, and CO_{2} activation on the carbonization yield and properties of cellulose-based carbon fibers. Synergistic effects are identified using the response surface methodology. This paper evidences that DAP and lignin could affect cellulose pyrolysis positively in terms of carbonization yield. Nevertheless, DAP and lignin do not have an additive effect on increasing the yield. In fact, combined DAP and lignin can affect negatively the carbonization yield within a certain composition range. Further, the thermogravimetric CO_{2} adsorption of the respective CFs was measured, showing relatively high values (ca. 2 mmol/g) at unsaturated pressure conditions. The CFs were microporous materials with potential applications in gas separation membranes and CO_{2} storage systems.Graphical abstract

Constructing nitrogen/sulfur co-doped hierarchical porous cellulose-based carbon derived from larch via regeneration by dissolution approach for supercapacitor

The effective strategies to increase the energy density of carbon-based supercapacitors are increasing the specific surface area (SSA) and heteroatom doping, however the methods to achieve such outcomes are often time-consuming and complicated. Herein, a time-saving and facile method was adopted to fabricate hierarchical carbonized wood electrodes with both delignification and partly dissolution/regeneration through NaOH/thiourea solution followed by carbonization. The partial dissolution/regeneration treatment not only generates the interconnected network structures on the surface of the regenerated wood and improves the porosity, but also achieves the efficient co-doping of nitrogen/sulfur heteroatoms. A relatively excellent activation was achieved by dissolving for only 3 h, with a SSA of 1416.25 m2/g, which was 2.86 times higher than the SSA of the samples carbonized directly with delignified wood. Remarkably, the as prepared electrode exhibits superior areal (specific) capacitance of 6.11 F/cm2 (413.6 F/g, 1.0 mA/cm2) and durability (98.9%, 12,000 cycles, 50 mA/cm2). In addition, a symmetrical supercapacitor (SSC) assembled from carbonized regenerated wood has an excellent energy density of 1.15 mWh/cm2 (51.24 Wh/kg) at a power density of 699 mW/cm (31.11 W/kg). This facile doping and activation method may be able to provide a new concept for the carbon electrode preparation of bio-based materials.