Biomass Precursors Research Articles

N, O and S co-doped hierarchical porous carbon derived from a series of samara for lithium and sodium storage: Insights into surface capacitance and inner diffusion

Efficiently selecting biomass precursors to prepare porous carbon with rich pore structure and heteroatom doping, and clearly distinguishing the storage behavior of Li+ and Na+ in porous carbon are still the key issues for the development and utilization of biomass-based carbon materials. In this work, four kinds of samara with a hollow structure are used as carbon sources to prepare an N, O and S co-doped hierarchical porous carbon. As the anode for Li/Na-ion batteries, the reversible specific capacity of N, O and S co-doped hierarchical porous carbon (HPC-UP-6) is 1072.3 mAh·g−1 (0.0744 A·g−1) and 333.2 mAh·g−1 (0.1 A·g−1), respectively. The ultra-high specific capacity reveals the rationality of preferentially selecting plant fruits with hollow structures as precursors. In addition, further comparative studies show that the contribution rate of surface-induced capacitance in sodium-ion batteries is more than 10% higher than that in lithium-ion batteries, indicating that Na+ tends to be stored on the surface of porous carbon. This principle of selecting biomass precursors and the new understanding of the storage mechanism of Li+/Na+ in biomass-based porous carbon can guide the design and preparation of new carbon materials with high capacity and high-rate performance.

Salt assisted fabrication of lignin-derived Fe, N, P, S codoped porous carbon as trifunctional catalyst for Zn-air batteries and water-splitting devices

Exploring inexpensive, effective, and robust multifunctional catalysts for simultaneously catalyzing oxygen reductive reduction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is critical to the practical application of high-efficiency zinc-air batteries and water-splitting devices. Herein, trifunctional catalyst by coupling FeNx, FePx into N, P, S codoped carbon framewrok (Fe-N-C/FePx/NPSC) can be realized via salt assisted strategy by using sodium hypophosphite as the salt template and sodium ligninsulfonate chelated with iron element as the precursor. The Fe-N-C/FePx/NPSC with large specific surface area (782 m2 g−1), high pore volume (0.52 cm3 g−1) and multiple active sites exhibits excellent catalytic performances for ORR (E1/2 = 0.9 V), OER (Ei=10 = 370 mV in alkaline solution) and HER (Ei=10 = 125/198 mV in acidic/alkaline solution). The Zn-air battery based on Fe-N-C/FePx/NPSC displays a high power density of 216.88 mW cm−2 and strong stability, and the water-splitting electrolyzer assembled by Fe-N-C/FePx/NPSC only needs 1.57 V to reach 10 mA cm−2, which are better than those of Pt/C + IrO2 based devices. The flexible Zn-air batteries assembled by Fe-N-C/FePx/NPSC exhibit high reliability under various deformation conditions, proving the potential for application in wearable devices. This work provides a potential way to design multifunctional carbon based electrocatalysts by using sustainable biomass precursors.

Local production of lactate, ribose phosphate, and amino acids by human triple-negative breast cancer

Upregulated glucose metabolism is a common feature of tumors. Glucose can be broken down by either glycolysis or the oxidative pentose phosphate pathway (oxPPP). The relative usage within tumors of these catabolic pathways remains unclear. Similarly, the extent to which tumors make biomass precursors from glucose, versus take them up from the circulation, is incompletely defined. We explore human triple negative breast cancer (TNBC) metabolism by isotope tracing with [1,2-13C]glucose, a tracer that differentiates glycolytic versus oxPPP catabolism and reveals glucose-driven anabolism. Patients enrolled in clinical trial NCT03457779 and received IV infusion of [1,2-13C]glucose during core biopsy of their primary TNBC. Tumor samples were analyzed for metabolite labeling by liquid chromatography-mass spectrometry (LC-MS). Genomic and proteomic analyses were performed and related to observed metabolic fluxes. TNBC ferments glucose to lactate, with glycolysis dominant over the oxPPP. Most ribose phosphate is nevertheless produced by oxPPP. Glucose also feeds amino acid synthesis, including of serine, glycine, aspartate, glutamate, proline and glutamine (but not asparagine). Downstream in glycolysis, tumor pyruvate and lactate labeling exceeds that found in serum, indicating that lactate exchange via monocarboxylic transporters is less prevalent in human TNBC compared with most normal tissues or non-small cell lung cancer. Glucose directly feeds ribose phosphate, amino acid synthesis, lactate, and the TCA cycle locally within human breast tumors.

Rapid discrimination of porous bio-carbon derived from nitrogen rich biomass using Raman spectroscopy and artificial intelligence methods

Granular porous bio-carbons were prepared by pyrolysis of different biomass precursors such as mung bean, black urad bean, and black grape seed, using ZnCl2 as an activating agent at different activation temperatures of 450–750 °C. The derived bio-carbons samples were extensively characterized using electron microscopy, surface area analysis, and CO2 adsorption capacity studies. As the activation temperature increased, the surface area, pore volume, nitrogen content, and the CO2 removal efficiency of the bio-carbons varied from 254 to 937 m2/g, 0.1241–0.4212 mL/g, 1.51–6.23%, and 2.11–5.48 mmol/g (at 25 °C under 3 bar pressure) respectively. Furthermore, Raman spectroscopic technique was used as a tool to understand the structural development that occurred in the biomasses during pyrolysis. Additionally, multivariate analysis such as combined Principal Component Analysis, partial least square-discriminant analysis (PLS-DA) was employed for the Raman data to discriminate the biomass based on their source and activation temperature. In addition, deep learning methods such as LeNET, ResNet, CAE were evaluated to classify the bio-carbon samples with respect to temperature and precursor material. All the models gave 100% accuracy of classification with respect to the temperature of activation. An overall classification accuracy of >92 ± 0.0665% was obtained for LeNET model.

Wide voltage-window biomass carbon-based MnO electrodes for supercapacitors

Biomass carbon-based MnO electrode materials were synthesized using ramie as the biomass precursor of carbon and potassium permanganate as the precursor of MnO. The ramie-activated carbon/manganese monoxide (RAC/MnO) composite electrodes exhibited a specific capacitance of 720 F/g at a current density of 0.5 A/g. A symmetric cell assembled using the composite electrodes showed a specific capacitance of 45 F/g at 0.5 A/g and an energy density of 12.25 Wh/kg at a power density of 350 W/kg. The excellent electrochemical performance was analyzed by characterizing the electrodes’ chemical composition, microstructure, crystal orientation, specific surface area, and pore distribution. Because of the large overpotential of MnO, the composite electrode’s working voltage reached 1.4 V, which is 40% higher than 1.0 V of traditional carbon electrodes. As such, supercapacitors can have higher energy density and power density with the RAC/MnO composite electrodes. The experimental equipment for synthesizing the electrodes is very simple and is promising for large-scale commercialization.

High-Performance and High-Voltage Supercapacitors Based on N-Doped Mesoporous Activated Carbon Derived from Dragon Fruit Peels.

Designing the mesopore-dominated activated carbon electrodes has witnessed a significant breakthrough in enhancing the electrolyte breakdown voltage and energy density of supercapacitors. Herein, we designed N-doped mesoporous-dominated hierarchical activated carbon (N-dfAC) from the dragon fruit peel, an abundant biomass precursor, under the synergetic effect of KOH as the activating agent and melamine as the dopant. The electrode with the optimum N-doping content (3.4 at. %) exhibits the highest specific capacitance of 427 F g–1 at 5 mA cm–2 and cyclic stability of 123% capacitance retention until 50000 charge–discharge cycles at 500 mA cm–2 in aqueous 6 M KOH electrolytes. We designed a 4 V symmetric coin cell supercapacitor cell, which exhibits a remarkable specific energy and specific power of 112 W h kg–1 and 3214 W kg–1, respectively, in organic electrolytes. The cell also exhibits a significantly higher cycle life (109% capacitance retention) after 5000 GCD cycles at the working voltage of ≥3.5 V than commercial YP-50 AC (∼60% capacitance retention). The larger Debye length of the diffuse ion layer permitted by the mesopores can explain the higher voltage window, and the polar N-doped species in the dfAC enhance capacitance and ion transport. The results endow a new path to design high-capacity and high-working voltage EDLCs from eco-friendly and sustainable biomass materials by properly tuning their pore structures.

Single-route synthesis of binary metal oxide loaded coconut shell and watermelon rind biochar: Characterizations and cyclic voltammetry analysis

Generally, the type of biomass precursors is one of the key factors affecting the properties of synthesized biochar. This novel study therefore examined the single-route preparation of coconut shell and watermelon rind biochar with the combination of two types of binary metal oxide, iron nickel oxide (Fe2NiO4), and cobalt iron oxide (CoFe2O4) by employing a novel vacuum condition in an electric muffle furnace. The samples were characterized by several methods such as Fourier transform infrared (FTIR), field emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) Surface Area. The optimum pyrolysis temperature for producing a high surface area of 322.142 m2/g and 441.021 m2/g for coconut shell biochar and watermelon rind biochar, respectively, was recorded at 600 °C. FTIR analysis revealed lesser adsorption bands found in FTIR spectrum of the samples with higher pyrolysis temperature (500–700 °C). In addition, FESEM results also revealed the surface changes of the samples with the impregnation of CoFe2O44 and Fe2NiO4. Furthermore, the value added application of biochar in electrochemical energy storage has been explored in the present work. In typical three-electrode configuration, WR-BMO 600 exhibits about 152.09 Fg−1 with energy density about 19.01 Wh kg−1.

Facile synthesis of macroalgae-derived graphene adsorbents for efficient CO2 capture

Graphene, emerging as one of the most promising class of adsorptive separation carbon material for its high specific surface area and strong surface chemical activity. Biomass especially sustainable biomass as graphene sources shows great potential at large scales under energy shortage era. In this paper, a kind of subtropical macroalgae (Sargassum Horneri, S.H.) was selected as the precursor, and a facile synthesis method based on KOH activation was used to prepare graphene. A continuous monitoring on the formation of graphene and a systematic investigation into biomass precursor were performed, paying special attention to parameters including activation temperature, the alkali and carbon ratio, the corresponding pore structure, and surface chemistry variation. Moreover, the CO2 adsorption properties of porous graphene were tested. The results showed that, S.H. is a kind of ideal graphene precursor. The optimum preparation of porous graphene by KOH activation was the carbonization temperature of 400 °C, the alkali carbon ratio of 4:1 and the activation temperature of 850 °C. The porous graphene displayed high specific surface area (∼1411 m2/g), pore volume (∼1.16 cm3/g), and abundant microporous and mesoporous structures. The as-prepared porous graphene exhibited good CO2 uptake capacity as 2.78 mmol/g at 30 °C and 1 bar. The CO2 adsorption rate equations of the graphene were consistent with the intraparticle diffusion model, indicating that the CO2 adsorption was mainly controlled by the pore structure, and additionally influenced by the chemical functional groups especially N on the surface.

Adsorption mechanism of Zn2+, Ni2+, Cd2+, and Cu2+ ions by carbon-based adsorbents: interpretation of the adsorption isotherms via physical modelling.

A theoretical physicochemical and thermodynamic investigation of the adsorption of heavy metals Zn2+, Cd2+, Ni2+, and Cu2+on carbon-based adsorbents was performed with statistical physics fundaments. Particularly, the experimental adsorption isotherms of heavy metal removal, at 30°C and pH 5, using adsorbents obtained from the pyrolysis of three biomasses (cauliflower cores, broccoli stalks, and coconut shell) were modelled and interpreted with a homogeneous statistical physics adsorption model. Calculations indicated that the heavy metal adsorption with these carbon-based materials was a multi-ionic process where several ions interact simultaneously with the same carboxylic functional group on the adsorbent surface. Adsorption capacities for these metal ions and adsorbents were correlated with electronegativity theory, which established that the adsorbate with the highest electronegativity was more readily adsorbed by the carboxylic functional groups available on the adsorbent surfaces. Also, the chemical compositions of biomass precursors explained achieved adsorption capacities for these metallic ions. The best adsorbent for heavy metal removal was obtained from CC biomass pyrolysis. Calculated adsorption energies for heavy metal removal could be associated with physisorption-type forces. Finally, the adsorption mechanism analysis was complemented with the determination of adsorption thermodynamic functions using the statistical physics.

Assessing the Importance of Pyrolysis Process Conditions and Feedstock Type on the Combustion Performance of Agricultural-Residue-Derived Chars.

The combustion performance of chars derived from vine shoots, wheat straw, and corn stover was investigated to assess the influence of both the biomass precursor and pyrolysis operating conditions. Chars were produced through slow pyrolysis at different peak temperatures (350 and 500 °C), pressures (0.1 and 0.5 MPa), and residence times of the vapor phase (50 and 150 s). From the thermogravimetric curves obtained under air, the combustion performance index (S) was calculated for each char. Apparent kinetics were also estimated using the Coats–Redfern method and assuming an F3/2 reaction model. Results show that the combustion patterns of chars were more influenced by the type of feedstock than by the pyrolysis conditions. Corn stover appeared to be the most interesting feedstock in order to produce chars with tuned reactivity. Results from partial least-squares (PLS) regression revealed that the most important factors affecting S were the contents of potassium (negative effect) and cellulose (positive effect) in the original biomass.

Efficient Continuous Hydrothermal Flow Synthesis of Carbon Quantum Dots from a Targeted Biomass Precursor for On–Off Metal Ions Nanosensing

Glucose, a readily available biomass precursor is used for the production of carbon quantum dots (CQDs) via a fast, efficient, and environmentally benign continuous hydrothermal flow synthesis (CHFS) process using supercritical water, an approach that can readily be scaled up for industrialization, producing materials with enhanced properties. The water-soluble CQDs exhibit an average particle size of 2.3 ± 0.5 nm, with an optimum emission intensity at 446 nm on excitation at 360 nm. The as-synthesized CQDs with no extra modification show promising sensitivity and good selectivity for the highly toxic, carcinogenic, and mutagenic chromium(VI) ion (limit of detection of 1.83 ppm) and for the essential bioactive transition metal, iron(II) ion (limit of detection of 6.09 ppm). The life-cycle assessment confirms that in comparison to the conventional batch synthetic method, the continuous hydrothermal flow synthesis process is significantly a more efficient and greener route for the synthesis of carbon quantum dots from the glucose biomass precursor.

Facile synthesis and superior capacitive behavior of cattail wool-derived hierarchical porous carbon

Biomass-derived porous carbon has been widely concerned as electrode material for supercapacitors, yet is severely hindered by the complex preparation process and low-efficiency. In this work, a facile solid-phase single-stage activation strategy is developed to fabricate cattail wool-derived porous carbon by using calcium carbonate (CaCO3) and potassium oxalate monohydrate (K2C2O4·H2O). The hard template effect of CaCO3, the activation of K2C2O4, and the interaction between CaCO3 and K2C2O4 endow the resultant carbon an interconnected hierarchically porous structure, enhancing capacitive performance. In particular, CWC-3.5-600, which is prepared with a mass ratio of 3.5 for K2C2O4·H2O to the biomass precursors and calcined at 600 °C, possesses a specific surface area of 1173.2 m2 g−1 and a total pore volume of 0.581 cm3 g−1. The optimal carbon exhibits a large specific capacitance (323.0 F g−1 at 0.5 A g−1, 268.8 F g−1 at 1.0 A g−1) and superior rate capability in the three-electrode configuration. Also, the CWC-3.5-600-based symmetrical supercapacitor delivers an energy density of 23.93 Wh kg−1 at 240 W kg−1, in addition to good cycling stability. This work proposes a simple, low-cost, and high-efficiency method for large-scale synthesis of biomass-derived porous carbon materials, which are potential in the advanced energy storage and conversion devices.

Hierarchically porous SiOx/C and carbon materials from one biomass waste precursor toward high-performance lithium/sodium storage

Silicon (Si)-based materials have emerged as promising anode materials owing to the theoretical capacity as high as 4200 mAh g−1 and satisfying working potential for lithium insertion. However, silicon-based anode materials inevitably face the dilemmas of huge volume variation and poor electric conductivity. In this study, three-dimensional (3D) hierarchically porous SiOx/C and carbon materials have been designed and fabricated from one renewable biomass precursor (i.e., bamboo shoot hulls) through low-temperature activated treatment and mildly aluminothermic reduction. The SiOx/C anode after pre-lithiation treatment achieves an initial discharge capacity of 1332 mAh g−1 and a high capacity of 1289 mAh g−1 after 400 cycles at 200 mA g−1 as anode electrode for half lithium-ion batteries (LIBs). When employed for full LIBs, the SiOx/C exhibits a specific capacity of 142 mAh g−1 at 0.1 C with prominent cyclic stability and exceptionally low volume expansion. Moreover, hierarchically porous carbons are also prepared from the same precursor through activation of CuCl2 and further removal of SiO2, exhibiting excellent electrochemical performances for lithium/sodium ion batteries.

Graphene-like porous carbon nanostructure from corn husk: Synthesis and characterization

Graphene-based materials have been considered as an outstanding candidate for energy storage and conversion due to their large theoretical surface area, high electronic conductivity, and excellent electrochemical stability. The production of graphene is usually from the exfoliation of precious flake graphite that is found in metamorphic rocks (such as limestone, gneiss, and schist). The flake graphite is distributed uniformly throughout the body of the rock. Currently, numerous researchers are trying to develop synthesis methods for graphene production from agro-waste. In Thailand, corn husks have been a great natural source to produce carbon because the corn husk is the bio-waste materials that are abundant, and the proper disposal method is needed. Hence, the preparation of graphene from corn husks or biomass precursors is a new alternative procedure to overcome the above-mentioned problem. Therefore, this paper will be focused on synthesizing graphene-like porous carbon nanostructure from corn husk through thermal combustion, twice modified Hummers’ method and thermal annealing. The obtained graphene-like porous carbon exhibits reliable structural morphology for energy storage materials.

Synthesis of porous carbon material based on biomass derived from hibiscus sabdariffa fruits as active electrodes for high-performance symmetric supercapacitors.

Carbon-based materials are manufactured as high-performance electrodes using biomass waste in the renewable energy storage field. Herein, four types of hierarchical porous activated carbon using hibiscus sabdariffa fruits (HBFs) as a low-cost biomass precursor are synthesized through carbonization and activation. NH4Cl is used as a chemical blowing agent to form carbon nanosheets, which are the first types of hibiscus sabdariffa fruit-based carbon (HBFC-1) sample, and KOH also forms a significant bond in the activation process. The prepared HBFC-1 is chosen to manufacture the symmetric supercapacitor due to its rough surface and high surface area (1720.46 m2 g−1), making it show a high specific capacity of 194.50 F g−1 at a current density of 0.5 A g−1 in a three-electrode system. Moreover, the HBFC-1 based symmetric supercapacitor devices display a high energy density of 13.10 W h kg−1 at a power density of 225.00 W kg−1, and a high specific capacity of 29 F g−1 at 0.5 A g−1. Additionally, excellent cycle life is observed (about 96% of capacitance retained after 5000 cycles). Therefore, biomass waste, especially hibiscus sabdariffa fruit based porous carbon, can be used as the electrode for high-performance supercapacitor devices.

Rational design and solvent-free synthesis of iron-embedded 2D composite materials derived from biomass for efficient oxygen reduction reaction

A facile and sustainable solvent-free shearing/graphitization method for the production of a series of 2DFe/BCs from various low-cost biomass precursors with enhanced ORR electrocatalytic activity in both alkaline and acid environments.

Porous carbon from Manihot Esculenta (cassava) peels waste for charge storage applications

The activation of carbon from Manihot Esculenta (cassava) peels as a sustainable biomass precursor was explored for application in supercapacitors (SCs); demonstrating a cheap and sustainable environmental friendly source of carbon materials for potential application as electrode materials for SC. The activation was carried out with three different activating agents namely potassium hydroxide (KOH), potassium bicarbonate (KHCO3) and potassium chloride in sodium thiosulphate (KCl–Na2S2O3). The obtained activated carbon (AC) material exhibited SSA up to 828 ​m2 ​g−1 for the KOH activation and the electrodes fabricated revealed a specific capacitance (CSP) (300 ​F ​g−1 at 0.5 ​A ​g−1), excellent rate capability and cycling stability (98% capacitance retention after 5000 cycles) in 6 ​M KOH aqueous solution. The study demonstrated an efficient and sustainable approach for high performance SCs by using biomass as a viable source of the carbon material for SC applications.

Performance studies of bamboo based nano activated carbon electrode material for supercapacitor applications

The vast majority of the activated carbons manufactured commercially, are supplied from non-renewable energy source based forerunner (oil and coal) which requires it to be costly and earth non-accommodating henceforth the expanding center around biomass precursors which are less expensive, promptly accessible, sustainable, fundamentally permeable and environmentally safe. Biomass-derived activated carbon material is essentially an unusual material that can be used for various applications such as wastewater treatment, cancer treatment, energy storage devices, and so on. This study aims to synthesize the nano activated carbon using Bamboo as the precursor under a Nitrogen atmosphere using KOH as an activating agent to increase the surface area and pore size properties of the electrode material. The microstructural and electrochemical characterization was carried out to know the structural morphology, crystallinity, and pore size of the particles. The surface area of synthesized 1273 m2/g, the average diameter of the pore is 1.92 nm and the pore volume of 0.6119 cm3/g was obtained using the Brunauer Emmett Teller (BET) test. The surface morphology and crystallinity of bamboo activated carbon was obtained using the Scanning Electron Microscope and X-Ray Diffraction. The electrochemical characterization of the developed supercapacitor reveals that the highest specific capacitance of 143F/g was observed at 5 mV scan rate in 1 M KOH electrolyte. Using Galvanic Charge Discharge, the efficiency retention was determined and it is reduced to 70% after 25,000 cycles.

From flax fibers to activated carbon electrodes: The role of fiber refining

Flax-based activated porous carbon materials (APCs) were prepared via KOH and urea synergistic activation in the carbonization process using flax pulp as a biocompatible and eco-friendly biomass precursor. A refining process was used to pretreat the flax pulp fibers, which has been known to improve and optimize the performance of APCs. The morphological and physicochemical structures of APCs were investigated, and the results showed that APCs exhibited high specific surface area and porous microstructure. Furthermore, APCs were rationally designed as a sustainable electrode material. The APC prepared by 60 °SR (Shopper-Riegler beating degree) flax pulp, named APC-60, exhibited the highest specific capacitance of 265.8 F/g at a current density of 0.5 A/g. The specific capacitance retention at 59% remained for the APC-60 electrodes at a high current density of 10 A/g. These results suggested that the flax-based APCs could be a promising carbon-based electrode material for sustainable electrochemical energy storage.

Synthesis of N-doped carbon based on the waste of Brosimum alicastrum from a pilot plant and evaluation of its electrocatalytic activity for the oxygen reduction reaction

AbstractThis work reports the synthesis and characterization of metal-free electrocatalysts made from Brosimum alicastrum waste as the carbon source. The residues were washed and grounded to a fine powder. The thermogravimetric analysis carried out on the raw sample showed that the optimal synthesis temperature is 700 °C. Thus, the raw sample was pyrolyzed at 700 °C and activated with potassium hydroxide (KOH) in a 2:1 ratio (KOH/fine power) to improve its properties. Afterwards, hydrazine was used as the nitrogen source for doping. The physicochemical characteristics of pyrolyzed, activated, and doped carbons were studied and their electrochemical properties were determined using cyclic and linear voltammetry techniques. The electrochemical measurements indicate that the sample doped at 140 °C has an acceptable onset potential (0.854 V vs. RHE), while the one doped at 160 °C shows the highest current density among the synthesized electrocatalysts (2.61 mA cm-2). Although the catalyst performance is lower compared to commercial 20% Pt/C, this biomass precursor favors the oxygen reduction reaction in alkaline media.