Carbon Microspheres Research Articles

Synthesis of monodisperse highly nitrogen-rich porous carbon microspheres for CO2 adsorption

Synthesis of monodisperse highly nitrogen-rich porous carbon microspheres for CO2 adsorption

The layered black phosphorus modified by heteroatomic carbon microspheres for energy storage

The layered structural black phosphorus (BP), as an emerging two-dimensional material, has aroused great interest due to its intriguing electrochemical properties, but its poor stability greatly limits its practical application. This work utilized a unique heteroatomic carbon microsphere (PZSC) obtained by carbonization of polyphosphazene microspheres as PZSC (-), and modified BP with PZSC using a simple ultrasound assisted liquid exfoliation technique to obtain BP/PZSC (+). The BP modified with PZSC greatly improved the cycling stability and specific capacitance, displaying a high specific capacitance of 843.1 F g−1 at 1 A g−1. The assembled hybrid BP/PZSC (+) // PZSC (-) supercapacitor exhibits high specific capacitance, power and energy density (57.1 F g−1, 799.9 W kg−1, 20.3 Wh kg−1) with excellent cycle stability (96%, 5000r). This work effectively promotes the application of BP-based and heteroatomic carbon-based materials in the field of supercapacitors.

Nickel ferrite nanoparticles doped on hollow carbon microspheres as a novel reusable catalyst for synthesis of N-substituted pyrrole derivatives

Pyrroles are widely spread worldwide because of their critical applications, especially pharmacology. An expedition method for one-pot synthesis of N-substituted pyrrole derivatives has been presented by a reaction between 2,5-dimethoxytetrahydrofuran and various primary aromatic amines in the presence of NiFe2O4 anchored to modified carbon hollow microspheres (NiFe2O4@MCHMs) as a recoverable reactive catalyst. The Classon-Kass method has been used to synthesize the pyrroles in excellent yields and short reaction times in the same direction with green chemistry rules. This reaction was carried out by employing NiFe2O4@MCHMs as a catalyst to make a simple procedure with short activation energy in water as an accessible, non-toxic, and biodegradable solvent. This catalyst provides a promising pathway to synthesize N-substituted pyrroles several times in a row through the recyclability without remarkable loss of its catalytic activity. The NiFe2O4@MCHMs nanocatalyst was characterized by applying FT-IR, XRD, FE-SEM, TEM, EDS, BET, TGA, VSM, and elemental mapping techniques. Also, the synthesized N-substituted pyrrole derivatives were identified using melting point, FT-IR, and 1H NMR analyses.

Co modified N, P, B tri-doped porous yolk-shell biochar microspheres as catalyst for oxygen evolution reaction

Designing low-cost and high-activity electrocatalysts is crucial for improving the slow kinetic process of the oxygen evolution reaction (OER) and meeting global energy demands. This study focuses on the preparation of a novel OER catalyst, labelled Co@NPBC, which exhibits a porous yolk-shell configuration. The structure of Co@NPBC consists of N, P, B-doped carbon microspheres, amalgamated with the transition metal Co, and it is fabricated via a simple impregnation–carbonisation method. The doping of heteroatoms has the potential to modify both the charge and spin density of carbon atoms, while the presence of Co enhances the electrical conductivity of the material, which accelerates the electron transmission process. The porous structure provided numerous active sites for the reaction to occur, specifically at the catalytic interface. Furthermore, the yolk-shell structure serves a supportive function, ensuring the stability of the overall catalyst architecture. Upon testing in an alkaline environment, the Co@NPBC material demonstrated exceptional OER catalytic activity (η10: 355 mV, Tafel slope: 71.4 mV·dec−1). The results showed that the synergistic effect of carbon microspheres doped with heteroatoms and Co nanoparticles increased the OER catalytic activity and subsequently enhanced water splitting efficiency. For a comparative analysis, catalysts with either single (Co@NC, Co@BC, and Co@PC) or double doping (Co@NPC, Co@NBC, and Co@BPC) were also prepared. The results showed that Co@NPBC exhibited better OER catalytic activity than the other catalysts.

Tunable synthesis of bimetallic hybrid multishelled hollow structure for high-performance aqueous alkaline batteries

Multishelled hollow structure (HoMS) with various metal components show alluring prospect due to the combined effects of various elements. But due to the different condensation and hydrolysis rates of different metal oxide precursors it is still a big challenge to synthesize multicomponent HoMSS. Here we report two different strategies: 1.Two-step strategy (TsS) and 2. One-step strategy (OsS) for the tunable synthesis of HoMSS with two transition metal oxide precursors (zinc chloride and titanium chloride) by using carbon microspheres as a hard template. As a result a number of crystalline mesoporous HoMSs of ZnO@TiO2 with varied thicknesses, high porosity, large specific surface area and different voids are synthesized. Synthesis strategies and conditions not only affect the shell numbers, thickness of the shell, pore size, surface area and size of the voids but also the amount of absorbed metal ions (Zn2+ and Ti4+) varied. We compared their performances as cathode in aqueous alkaline battery and found that the ZnO@TiO2 HoMSS synthesized by OsS (triple shelled) exhibit excellent high potassium storage capacity, good rate capability, outstanding reversibility, and steady long cyclic life. The thinner shell, larger pore size, high surface area, and bigger voids contribute a distinctive buffering zone for charge-discharge, thus improving the structural stability and enhance the cycling stability during OH intercalation/de-intercalation process. ZnO@TiO2 triple shelled HoMSS with large pore size and big voids delivers a high discharge specific capacity of 260 mAhg−1 at a current density of 1 Ag−1, and capacity enhanced to 270 mAhg-1 over 1000 cycles.

LFP-based binder-free electrodes produced via fused filament fabrication

Carbon coated-LiFePO4 (LFP) is a strong candidate as lithium-ion battery (LiB) cathode due to the combination of safe operation, stable electrochemical performance and positive environmental impact as does not depend on Co, which is toxic and a critical raw material. In this work, we report the development of binder-free LFP cathodes fabricated by fused filament fabrication (FFF) technology. Several novel carbon-LFP filaments have been developed to 3D-print LiB cathodes, analysing both the carbon to LFP ratio in the formulation and also the impact of the carbon source used as current collector, i.e. glassy carbon (GC) microspheres or carbon black (CB), in the electrochemical performance. LFP remained stable upon debinding and sintering at temperatures as low as 500 °C as determined by x-ray diffraction. The conductivity of 3D printed LFP monoliths was 2.06 × 10−4 S∙cm−1 at 50 °C, which is fairly close to that of LFP produced via conventional processing. This is mainly attributed to the preservation of the carbon coating around the LFP particles after debinding and sintering under controlled Ar atmospheres. The LFP-based electrodes containing CB or GC microspheres as conductive additives exhibited specific capacities of 150 mAh g−1, and over 95% coulombic efficiency after 100 cycles, showing no significant performance losses. These results largely exceed the performances reported for previous LFP-based electrodes produced via FFF as the non-active binder is removed upon fabrication.

Electrochemical DNA Sensor for adh 1 Gene Sequence from Corn Endogenous with Carbon Microsphere Modified Electrode

Electrochemical DNA Sensor for adh 1 Gene Sequence from Corn Endogenous with Carbon Microsphere Modified Electrode

Amine-Aldehyde Condensation-Derived N-Doped Hard Carbon Microspheres for High-Capacity and Robust Sodium Storage.

Hard carbon is generally accepted as the choice of anode material for sodium-ion batteries. However, integrating high capacity, high initial Coulombic efficiency (ICE), and good durability in hard carbon materials remains challenging. Herein, N-doped hard carbon microspheres (NHCMs) with abundant Na+ adsorption sites and tunable interlayer distance are constructed based on the amine-aldehyde condensation reaction using m-phenylenediamine and formaldehyde as the precursors. The optimized NHCM-1400 with a considerable N content (4.64%) demonstrates a high ICE (87%), high reversible capacity with ideal durability (399 mAh g-1 at 30mA g-1 and 98.5% retention over 120 cycles), and decent rate capability (297 mAh g-1 at 2000mA g-1 ). In situ characterizations elucidate the adsorption-intercalation-filling sodium storage mechanism of NHCMs. Theoretical calculation reveals that the N-doping decreases the Na+ adsorption energy on hard carbon.

A novel micro-sphere activated carbon synthesized from waste cigarette butts for ammonia adsorption

Waste cigarette filters mainly contain hardly degradable cellulose acetate, toxic nicotine, and traces of heavy metals, and therefore cause environmental pollution hazards when discarded. In order to convert cigarette butt waste into a valuable product, this article investigates the preparation of activated carbon from cigarette butts via a two-step process of hydrothermal reaction and a subsequent chemical activation with phosphoric acid as an activator. During hydrothermal reaction, it was found that a process of decarboxylation and dehydration cleavage of acetate occurs, leading to micron fragments and subsequent agglomeration into carbonaceous micro-spheres. The cigarette-butts-derived activated carbon micro-spheres have a high BET surface area of ∼ 1406 m2/g and NH3 adsorption capacity of ∼ 35.9 mg/g. It was revealed that the ammonia adsorption capacity tends to be positively and linearly correlated with the acidic functional group content of the activated carbon surface while negatively with BET surface area.

Hydrothermal carbon microspheres and their iron salt modification for enhancing biohydrogen production

Dark fermentation (DF) for hydrogen (H2) evolution is often limited to industrial application due to its low H2 yield. In this work, hydrothermal carbon microspheres (HCM) and iron modified HCM (Fe-HCM) were prepared by hydrothermal process using waste corn cob. Subsequently, HCM and Fe-HCM were used in DF for more H2. The highest H2 yields amended with HCM and Fe-HCM at 600 mg/L were achieved to be 119 and 154 mL/g glucose (0.87 and 1.2 mol H2/mol glucose), respectively, being 24% and 59% higher than that of control yield. Soluble metabolites revealed HCM and Fe-HCM promoted butyric acid-based DF. Microbial composition depicted that HCM and Fe-HCM improved the abundance level of Firmicutes from 35% to 41% and 56%, while the abundance level of Clostridium_sensu_stricto_1 rose from 25% to 38% and 51%, respectively. This provides valuable guidance for hydrothermal carbon used in biofuel production.

Lignin-derived sulfonate base metal-free N, S co-doped carbon microspheres doped with different nitrogen sources as catalysts for oxygen reduction reactions

The oxygen reduction reaction (ORR) is an important step in the widespread application of metal-air batteries, so it is necessary to study and develop low-cost and efficient metal-free carbon-based catalysts to catalyze the ORR reaction. Heteroatomic doping, especially N and S co-doped carbon materials, has received much focus as a promising ORR catalyst. Meanwhile, the lignin material has high carbon content, wide source, and low price, and has wide application prospects for the preparation of carbon material catalysts. Here we report a hydrothermal‑carbonation preparation method for the synthesis of carbon microspheres by utilizing lignin derivatives as carbon precursors. And a variety of N, S co-doped carbon microsphere materials were prepared by adding different nitrogen sources (urea, melamine, NH4Cl) to the microspheres. The N, S co-doped carbon microspheres (NSCMS-MLSN) catalysts achieved with NH4Cl as the nitrogen source displayed superior RR catalytic activity with high half-wave potential (E1/2 = 0.83 V vs. RHE) and current density (JL = 4.78 mA cm−2). This work provides some references on the method of preparing carbon materials co-doped with N and S and the choice of nitrogen sources.

ZIF-Derived Carbon Microspheres for High-Performance Zinc-Ion Capacitors

ZIF-Derived Carbon Microspheres for High-Performance Zinc-Ion Capacitors

Duckweed derived N, P-doped carbon microspheres supported Ru as highly active catalyst for electrocatalytic hydrodechlorination diclofenac

In order to improve degradation efficiency and reduce electrode cost, carbon microspheres (CM) particle electrode was prepared from readily available duckweed as a raw material for electrocatalytic hydrodechlorination. The surface structures and chemical characteristics of the CM were regulated by adjusting the pyrolysis temperature. When pyrolysis was performed at 650 °C, carbon microspheres (CM-650) with large surface areas that are rich in heteroatoms (N, P) and show high electrical conductivity are obtained. After the Ru catalyst was supported, the Ru/CM-650 as particle electrode forming a three-dimensional (3D) electrochemical reaction system exhibits high electrocatalytic performance for diclofenac (DCF) hydrodechlorination with dechlorination efficiency of more than 90% in 150 min. Furthermore, the Ru/CM-650 has good stability for repeated use, which is attributed to the synergistic interaction between N and P elements improving the stability of the catalyst.

CoFe2O4 decorated graphene/C18-functionalized mesoporous silica nanocomposites prepared for magnetic enrichment and electrochemical detection of promethazine in beef

Promethazine (PHZ) is used as a sedative in veterinary medicine, and its residue can threaten the health of human. The electrochemical detection of PHZ is suitable method for application in the field. However, the traditional electroanalysis is difficult to perform directly in meat samples due to matrix interference. This work integrates magnetic solid-phase extraction and differential pulse voltammetry for highly sensitive and selective determination of PHZ in beef and beef liver for the first time. CoFe2O4/graphene coated with C18-functionalized mesoporous silica (MG@mSiO2-C18) is synthesized as dispersed magnetic adsorbent to extract PHZ. Magnetic glassy carbon electrode modified with nitrogen-doped hollow carbon microspheres (HCM) attracts the MG@mSiO2-C18 with PHZ, and directly detects the PHZ without elution procedure. MG@mSiO2-C18 can separate PHZ to avoid the interference of impurities on following detection, and also concentrate PHZ on magnetic electrode. Additionally, the electrode modification with HCM can amplify the electrochemical signal of PHZ. Finally, the integrated PHZ determination method exhibits a wide linear range from 0.08 µmol/L to 300 µmol/L with a low limit of detection of 9.8 nmol/L. The beef sample analysis presents excellent recovery, demonstrating that this protocol is promising for the rapid and onsite detection of PHZ in real meat samples

Novel Bilayer-Shelled N, O-Doped Hollow Porous Carbon Microspheres as High Performance Anode for Potassium-Ion Hybrid Capacitors

HighlightsProposing a one-step pyrolysis strategy to fabricate a novel bilayer-shelled N, O-doped hollow porous carbon microspheres (NOHPC) anode.The optimized NOHPC anode displays a high K-storage capacity of 325.9 mAh g−1 at 0.1 A g−1 and excellent rate performance (201.1 mAh g−1 at 5 A g−1 after 6000 cycles).The assembled NOHPC//hollow porous activated carbon microspheres (HPAC) potassium ion hybrid capacitors deliver a high energy density of 90.1 Wh kg−1 at a power density of 939.6 W kg−1 even over 6000 cycles.

Machine learning-guided the fabrication of nanozyme based on highly-stable violet phosphorene decorated with phosphorus-doped hierarchically porous carbon microsphere for portable intelligent sensing of mycophenolic acid in silage

Violet phosphorene (VP) have been proved to be more stable than black phosphorene, but few reports for its application in electrochemical sensors. In this study, a highly-stable VP decorated with phosphorus-doped hierarchically porous carbon microsphere (PCM) with multiple enzyme-like activities as a nanozyme sensing platform for portable intelligent analysis of mycophenolic acid (MPA) in silage with machine learning (ML) assistance is successfully fabricated. The pore size distribution on the PCM surface is discussed using N2 adsorption tests, and morphological characterization indicates that the PCM is embedded in the layers of lamellar VP. The affinity of the VP-PCM nanozyme obtained under the guidance of the ML model reaches Km = 12.4 μmol/L for MPA. The VP-PCM/SPCE for the efficient detection of MPA exhibits high sensitivity, a wide detection range of 2.49 μmol/L - 71.14 μmol/L with a low limit of detection of 18.7 nmol/L. The proposed ML model with high prediction accuracy (R2 = 0.9999, MAPEP = 0.0081) assists the nanozyme sensor for intelligent and rapid quantification of MPA residues in corn silage and wheat silage with satisfactory recoveries of 93.33%–102.33%. The excellent biomimetic sensing properties of the VP-PCM nanozyme are driving the development of a novel MPA analysis strategy assisted by ML in the context of production requirements of livestock safety.

Nickel-embedded hierarchically-porous carbon microspheres as a multifunctional separator modifier for achieving advanced lithium-sulfur batteries

Lithium-sulfur batteries (LSBs), one of the most promising electrochemical energy storage systems, are in the spotlight due to their high theoretical energy density, alongside environmental friendliness and low cost of sulfur. Several unforgiving issues, however, hamper their commercial applications, such as the notorious shuttle effect of intermediary polysulfides and retarded redox kinetics, growth of dendritic Li, among other things. The crux of sorting out the problems above is designing a versatile material with good electrical conductivity, catalytic activity, together with abilities in suppression of polysulfide shuttling and Li dendrite growth. In this work, a composite of Ni nanoparticles embedded in the gradient-porous carbon microspheres (Ni/PCMS), acting like a miniature reactor, was fabricated as a separator modification material. Adequate electron conductivity can be guaranteed by the carbon substrate and the inlays of Ni nanoparticles. The physical/chemical adsorption and high Li+ transference number of Ni/PCMS assure suppressed shuttle effect and Li dendrite growth, respectively. Catalytic activity is fulfilled with the exposed Ni active sites. As a consequence, the batteries based on Ni/PCMS-modified separators achieve a high initial discharge capacity of 1426.7 mAh g−1 at 0.1 C and a low capacity fading rate of 0.078% per cycle over 800 cycles at 1 C. Even under a high sulfur mass loading of ∼ 3.0 mg cm−2, the battery still displays a superior rate performance of 555.6 mAh g−1 at 0.5 C. This work provides a thought for the rational design of a wide range of separator modifiers for high-performance Li-S batteries.

Investigation of charge storage in admixture of dextrose derived interconnected carbon spheres and micro-sized silicon

This work reports the investigations and electrochemical properties of a material, prepared by micro-sized Si (mSi) (upto 50 μm) which were partially coated with upto ~7 μm sized carbon microspheres (CS). The mixture of mSi enwrapped with CS ([email protected]) was fabricated using a low temperature and facile hydrothermal carbonization (HTC) of dextrose. XRD and Raman study revealed an amorphous phase due to carbon/SiO2 and a highly disordered nanocrystalline graphite respectively. Also, FTIR suggested the SiO bending and symmetric stretching of linear SiOSi. The electrochemical investigation with three cell assembly of fabricated [email protected] as an electrode material for supercapacitor application exhibited a maximum specific capacitance of 278.79 F g−1 at 5 mV s−1 scan rate which is around 7 times as calculated for pristine mSi powder. In [email protected], conducting, amorphous and nano crystalline carbon combined with mSi exhibited enhanced specific capacitance and a low equivalent series resistance (ESR). mSi served as anchor and contributed to enhancing specific capacitance and providing 2 V voltage window. This work opens the possibility of designing energy materials with the waste Si and pseudocapacitive materials.

Synthesis of hierarchical binary core‐branch nanocomposite of carbon microspheres@α‐Fe2O3 for enhancing electrochemical behavior

AbstractA facial strategy for the synthesis of hierarchical binary core‐branch carbon microspheres (CMS)@α‐Fe2O3 is presented. X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), energy‐dispersive X‐ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution TEM (HR‐TEM), and Brunauer–Emmett–Teller (BET) were used to characterize the structural and morphological properties of the products. XRD diffraction analysis of CMS@α‐Fe2O3 reveals the highly crystalline nature of α‐Fe2O3 in the hierarchical binary core‐branch CMS@α‐Fe2O3 nanocomposite. Morphological analyses show that the α‐Fe2O3 shell layer grew onto the surface of CMS to form nanoscale heterointerfaces in the core‐branch structure, demonstrating the effectiveness of the synthesized route. More importantly, CMS@α‐Fe2O3 demonstrated superior electrochemical behavior to CMS. The enhanced CMS@α‐Fe2O3 electrochemical performance can be attributed to its large specific surface area, which allows for the rapid transfer of electrons into the electrode during the redox process.

Hydrothermal synthesis of carbon-coated mixed crystalline phase TiO2 nanoparticle carbon microsphere composites as high performance anode materials for Li-ion batteries

Hydrothermal synthesis of carbon-coated mixed crystalline phase TiO2 nanoparticle carbon microsphere composites as high performance anode materials for Li-ion batteries