Porous Carbon Nanospheres Research Articles

Controlled fabrication of hierarchical porous carbon nanospheres with high doped nitrogen content for high-performance adsorbent of biomacromolecule

Constructing nitrogen-doped porous carbons with high specific surface area, rapid mass transfer channels, and positive charge is a crucial requirement for high-performance adsorbents. Herein, by the kinetic self-assembly synthesis strategy, we prepared nitrogen-doped hierarchical porous carbon spheres (N-HPCS) with adjustable pore structure, high specific surface area, and high nitrogen doping content (8.88 %). By using ethylenediamine as an assisted polymerization and assembly agent, the hydrolysis and condensation rate of tetraethyl orthosilicate (TEOS) as the silica source and the condensation rate of 3-aminophenol and formaldehyde as the phenolic resin precursor were controlled by adjusting ammonia volume as the alkaline catalyst to tune kinetic self-assembly of silica and phenolic resin components, thus achieving their simultaneous or sequential nucleus and growth. After carbonization and selective silica etching, three types of carbon nanospheres with center-radial pores, hollow center-radial pores and hollow structure were obtained. High nitrogen doping content endowed the nanospheres with positive charge. Through adsorption experiments on the bovine serum albumin (BSA) and Hemoglobin (Hb) as typical biological macromolecules, hollow carbon nanospheres with center-radial pores exhibited excellent adsorption performance for BSA(622.34 mg g−1) and Hb(759.96 mg g−1). Our fabricated N-HPCS may become a potential candidate for high-performance adsorption materials.

One-pot synthesis of porous carbon nanospheres supported CuPd alloy catalysts for the hydrogenation-dechlorination of 2,3,6-trichloropyridine

Hydrogenation-dechlorination to produce 2,3-dichloropyridine is important for the next-generation pesticides. In this work, we successfully synthesized porous carbon nanospheres supported CuPd alloy nanoparticles via a simple and efficient one-pot strategy. Furthermore, by adjusting the Cu/Pd ratio and carbonization temperature, the obtained Cu2Pd1@PCNs-500-H2O2 showed the highly catalytic activity for the hydrogenation-dechlorination of 2,3,6-trichloropyridine with a conversion rate of 70.1 % and selectivity of 71.2 %. The catalyst showed outstanding catalysis performance even after five cycles. This simple and rapid one-pot strategy provides a new approach for the large-scale synthesis of efficient heterogeneous catalysts and offers an effective solution for reducing the high costs associated with precious metals.

A molecular-chemistry-manipulation strategy toward functional lignin-based porous carbon nanospheres with tunable-pore structure

Porous carbon nanospheres derived from biomass materials have inspired numerous interests in various areas. Nevertheless, their fabrications mainly depend on template-assisted or chemical activation routes. Here, a molecular-chemistry-manipulation strategy was proposed innovatively by taking advantage of the heterogeneous self-condensation characters of lignin molecules under thermal stimulation, opening a practical and versatile synthetic platform for the construction of lignin-based hierarchical porous carbon nanospheres (LHPCS). We can manipulate the condensed kinetics by tuning the environmental variables and forming designated nanospheres with inhomogeneous molecular chemistry. This intraparticle difference could provide a possibility to tune its refined structure for synthesizing hierarchical porous carbon nanospheres. Such LHPCS behaved the specific surface area of 962 m2 g−1 and pore volume of 0.76 cm3 g−1, as well as regulable pore ratios (15.5–22.9 % of macropore, 12.7–37 % for mesopore and 45–68.9 % for micropore). Besides, the monodisperse spherical morphology with hierarchical interleaved channels affords them excellent performance in optical management and energy storage, including pore-determined photothermal properties, extremely low reflectance of ca. 1.9 %, stable multi-angles specular reflectance, and anti-self-discharge induced by charge rearrangement. Our proposed molecular chemistry strategy provides an alternative pathway for constructing gradient and adjustable pore structures.

Boosting Li–S Battery Performance by Regulating Microstructures of Porous Hollow Carbon Nanospheres from Lignites

Boosting Li–S Battery Performance by Regulating Microstructures of Porous Hollow Carbon Nanospheres from Lignites

Rigid-flexible coupling multistage carbon composite materials based on hybrid crosslinking as anodes for ultra long-cycling lithium-ion batteries

Graphene have garnered considerable attention owing to their disordered structure, wide layer spacing, and cost-effectiveness. The hierarchical porous structure of porous reduced graphene oxide (rGO) nanosheets with hollow carbon nanospheres offers advantages such as an intact conductive network and a robust structure. However, since the hollow carbon nanospheres are physically in contact with rGO, they are randomly dispersed on the graphene surface, severely impeding fast electron transport and resulting in poor electrochemical performance. In this study, we introduced a third layer of a polypyrrole (PPy) -derived carbon film on the basis of porous rGO sheets and hollow carbon nanospheres. The HCGP-200 anode was successfully prepared to effectively encapsulate hollow carbon nanospheres on rGO sheets through the synergistic effect of rGO and the PPy-derived carbon film. The HCGP-200 anode exhibits robust cycling performance (780 mAh g−1 after 2200 cycles at 5 A g−1) and excellent rate capacity. Additionally, it demonstrates outstanding cycling stability and remarkable capacity retention (450 mAh g−1 after 3000 cycles) even at ultra-high current densities of 20 A g−1. The ingenious design and preparation of HCGP-200 is of great significance in guiding the application of high-power appliances.

Multi-shelled hollow porous carbon nanospheres-based evaporator for highly efficient solar-driven desalination

Carbon-based materials stand out as photothermal materials for interfacial solar evaporation due to their high solar absorptance, chemical stability, adjustable structure, ease of preparation, and low cost compared to other candidate materials. Development of multifunctional carbon-based materials that can endow the fabricated evaporators with reduced energy loss and evaporation enthalpy is highly demanded to achieve extraordinary evaporation rates. Herein, high-solar-absorptivity multi-shelled hollow porous carbon nanospheres are fabricated and incorporated with an insulating hydrogel bottom layer into an integrated solar evaporator. It achieves a fast photothermal response and a remarkably high solar evaporation rate of 2.4 kg m−2 h−1 under one sun. Multiphysics simulation indicates that the porous multi-shelled hollow structure enables sufficient and effective interactions between water and the hydrophilic carbon surfaces, thus producing more intermediate water (IW) and lowering the evaporation enthalpy. The solar-driven water evaporation in the evaporator is probed by in-situ low-field nuclear magnetic resonance relaxation time measurements, based on which conversion of free water (FW) into IW during solar evaporation is proposed. The molecular dynamics simulations reveal that the evolution of FW clusters into IW is facilitated on the carbon surface, thus replenishing the evaporated IW and maintaining continuous high evaporation rates. The demonstrated solar evaporator exemplifies the effectiveness of structural and thermal management in enhancing solar-driven desalination.

Modulating the Energy Barrier via the Synergism of Cu3P and CoP to Accelerate Kinetics for Bolstering Oxygen Electrocatalysis in Zn-Air Batteries.

Modulating the energy barrier of reaction intermediates to surmount sluggish kinetics is an utterly intriguing strategy for amplifying the oxygen reduction reaction. Herein, a Cu3P/CoP hybrid is incorporated on hollow porous N-doped carbon nanospheres via dopamine self-polymerization and high-temperature treatment. The resultant Cu3P/CoP@NC showcases a favorable mass activity of 4.41 mA mg-1 and a kinetic current density of 2.38 mA cm-2. Strikingly, the catalyst endows the aqueous Zn-air battery (ZAB) with a large power density of 209.0 mW cm-2, superb cyclability over 317 h, and promising application prospects in flexible ZAB. Theoretical simulations reveal that Cu functions as a modulator to modify the free energy of intermediates and adsorbs the O2 on the Co sites, hence rushing the reaction kinetics. The open and hydrophilic hollow spherical mesoporous structure provides unimpeded channels for reactant diffusion and electrolyte penetration, whereas the exposed inner and outer surfaces can confer a plethora of accessible actives sites. This research establishes a feasible design concept to tune catalytic activity for non-noble metal materials by construction of a rational nanoframework.

Thiol functionalized porous carbon nanospheres: Synthesis, characterization, experimental and DFT studies

Thiol-modified nanoporous structured frameworks prove to be efficient trapping agents for eliminating mercury (Hg(II)) ions from water. In this work, we synthesized porous carbon nanospheres and chemically functionalized them with l-cysteine molecules following a Fischer esterification reaction and investigate them for selective Hg(II) separation. The material was characterized for functional group analysis, surface morphology and water contact angle measurement by using several spectroscopic and optical techniques likely FT-IR, XPS, SEM, TEM and goniometer analyzer. The column packed material shows selective extraction of trace Hg(II) ions at wide pH range. The selectivity of Hg(II) is primarily attributed to Lewis soft–soft acid–base chelation, wherein Hg(II) forms complexes with the thiol functionalities of the adsorbent. Density functional theory (DFT) calculations suggest that the fast energetically favorable R–SH–Hg–OR complex formed over R–S–Hg–NH–R bidentate complexes, thereby promoting selective extraction of Hg(II). The preconcentration limit for Hg(II) achieved at pH 6 was found to be 0.37 ppb. The instrumental detection limit (3 s/m) obtained after preconcentration of 11 blank runs is found to be 0.04 ppb with the relative standard deviation of 3.68 %. The accuracy of the proposed column method was validated by analyzing several real samples with enrichment factor of 100 and after spiking with varying amount of analyte. The method shows a good recovery of 97–100 % of spiked amount with RSD <5 %.

Nitrogen-doped magnetic porous carbon nanospheres derived from dual templates-induced mesoporous polydopamine coated Fe3O4 for efficient extraction and sensitive determination of volatile nitrosamines by gas chromatography-mass spectroscopy

N-nitrosamines (NAs) are highly carcinogenic compounds commonly found in food, beverages, and consumer products. Due to their wide polarity range, it is challenging to find a suitable carbon adsorbent that can simultaneously adsorb and enrich both polar and nonpolar NAs with good recovery. In this study, nitrogen-doped magnetic mesoporous carbon nanospheres (M-MCN) were prepared and employed as an adsorbent for magnetic solid-phase extraction (MSPE) to extract and concentrate four NAs. The introduction of nitrogen functional groups enhanced the hydrophilicity of the carbon material, allowing M-MCN to achieve a balance between hydrophilicity and hydrophobicity, resulting in good recovery for both polar and nonpolar NAs. A method combining MSPE with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of NAs in processed meat and alcoholic beverages. The method exhibited a good linear range (1–100 ng g−1, r2 > 0.9967) and trace-level detection (0.53–6.6 ng g−1). The recovery rates for the four NAs ranged between 85.7 and 110.7 %, with intra-day precision expressed as relative standard deviation (RSD) between 4.1 and 10.7 %, and inter-day precision between 4.8 and 12.9 %. The results demonstrated not only good accuracy and precision but also provided a new adsorbent for the enrichment of trace-level NAs in processed meat and alcoholic beverage samples.

High Capacitance Based on Vacancy Defective Porous Carbon in Ionic Liquid

AbstractPorous carbons have been extensively studied in electrochemical capacitors (ECs). However, low capacitance remains a limitation due to the electrical double layer (EDL) storage mechanism when porous carbons are used in ionic liquids (ILs) based ECs. Herein, the nitrogen‐derived vacancy defects in porous carbon nanospheres are found which can boost capacitive charge storage and present reversible high capacitance of 427 F g−1 in pure IL electrolyte, equal to a normalized area capacitance (CA) of 16 µF cm−2, surpassing the theoretical EDL CA (≈11 µF cm−2). When used as capacitive cathode, the assembled Lithium hybrid capacitor express high energy density of 635 Wh kg−1 based on active material under much high‐power density of 14.5 kW kg−1. A combination of control experiments and density functional theory investigation indicate that the EC's performance improvement mostly stems from strong interactions at vacancy defects, triggering extraordinary faradaic capacitance. The results shed light on defect engineering for realizing extra faradaic capacitance of carbon materials, and open up new opportunities for improving EC's energy density.

In-situ copper-loaded hollow porous carbon nanospheres derived from phenolic resin for thermal energy storage

Hollow porous carbon nanospheres (HPCS) are ideal scaffolds for phase change materials in thermal energy storage. However, their synthesis traditionally relies on template-based routes, involving tedious procedures and high costs. This study presents a facile method for preparing HPCS through one-step carbonization of phenolic resin using CuCl2 as the activation agent. This mild activation agent not only helps create a rich porous structure, but also maintains the hollow spherical architecture of the polymer precursor. More importantly, copper ions are reduced to copper nanoparticles during the carbonization process and are in-situ loaded into porous carbon, enhancing the thermal conductivity of the scaffold. After incorporating paraffin, the resulting composite exhibits a high phase change enthalpy of 104.4 J g−1, improved thermal conductivity of 0.95 W m−1 K−1, and excellent thermal cycling stability (100.5 J g−1 after 50 heating-cooling cycles), indicating significant potential for thermal energy storage and management.

Leaf‐Mimicking Superstructured Porous Membrane with Multiple Bioactive Pro‐Healing Functions for Effective Guided Bone Regeneration

AbstractBarrier membrane, a key material for guided bone regeneration surgery, is applied between soft and hard tissue interfaces in complex oral environment. The abilities to integrate contradictory requirements and self‐regulate the local microenvironment are highly desirable for barrier membrane but remain challenging to achieve. Herein, inspired by the leaf's hierarchical multifunctional synergy, a kind of superstructured porous membrane (SPM), integrating asymmetric surface pores, interconnected macropores and functional micropores, is developed based on the combination of breath figure and phase separation. For the SPM, the densely porous layer can inhibit penetration of soft tissue cells and maintain osteogenic space, and the loosely porous layer with interconnected microporous channels can effectively promote the adhesion and proliferation of osteoblasts, help to transport nutrients, and expose functional components. Meanwhile, porous carbon nanospheres introduced into SPM as multifunctional core components can ameliorate the undesirable microenvironment by scavenging reactive oxygen species, repairing bioelectrical environment, and killing bacteria, thus achieving multiple bioactive pro‐healing functions for efficient bone regeneration in vivo. These findings can open an appealing avenue for developing high‐performance barrier membranes as well as many other implant materials.

Regulating horizontal lamellar Zn to uniformly deposit under and on the hollow porous carbon nanosphere coating for dendrite-free metal Zn anode

To address dendrite, corrosion and side-reaction issues of metal Zn anode, hollow porous carbon nanospheres (HPCN) are designed to coat Zn anode. The HPCN coating as artificial interface alleviates hydrogen evolution reaction and Zn corrosion. The cavities and mesopores of HPCNs provide plentiful channels for substance transfer, homogenizing Zn2+ flux. The high electronic conductive HPCNs greatly homogenizes electronic field. These leads to low contact angel, nucleation overpotential and activation energy; high Zn2+ transference number and exchange current density. Highly homogeneous Zn2+ flux and electric field strongly regulate Zn plating/stripping behavior, and facilitate the uniform deposition of dense horizontal lamellar Zn under and on the HPCN coating. Zn dendrites induced by 2D diffusion and tip effect are inhibited. The by-products are also limited. Consequently, HPCN coating significantly improves long-term cycling lifespan and plating/stripping efficiency (2420 h at 1 mA cm−2, 1 mAh cm−2; 1515 h at 5 mA cm−2, 1 mAh cm−2; 290 h at 10 mA cm−2, 10 mAh cm−2). HPCN@Zn//MnVO full cell sustains discharge capacity of 149 mAh g−1 after 400 cycles at 1 A/g. Electronic/ionic conductive HPCNs uniquely regulate Zn plating/stripping behavior under and on the coating, stable Zn anode, and shed new light on interface engineering.

Fabrication of novel nitrogen-doped porous carbon nanospheres for high-performance supercapacitors.

A completely new type of nitrogen-doped polymer nanosphere and the derived nitrogen-doped porous carbon nanospheres were produced by taking 2,4-diamino-6-hydroxypyrimidine as the precursor. When functioning as electrode materials, they demonstrated extraordinary electrochemical performance, offering a powerful candidate for supercapacitors.

Cobalt-zinc carbides embedded in N-doped porous carbon nanospheres as polysulfide mediators for efficient lithium-sulfur batteries.

Developing high-efficiency interlayer catalysts is a promising tactic for improving the cycling performance of rechargeable lithium-sulfur (Li-S) batteries. Herein, using the Prussian blue analogue as the precursor, cobalt-zinc carbide nanocrystal-embedded N-doped porous carbon (Co3ZnC@NC) is synthesized via simple post-carbonization. The obtained Co3ZnC@NC nanospheres exhibit a robust core-shell structure showing good conductivity, high porosity and available metal active sites, favoring the interfacial charge transfer and the electron transport upon electrochemical reactions. The results demonstrate that the Co3ZnC@NC catalyst is quite suitable for boosting the adsorption and redox conversion kinetics of soluble polysulfides. When acting as the separator interlayer, Co3ZnC@NC contributes to improved Li-S batteries with a high discharge specific capacity of 1659.8 mA h g-1 at 0.1C and superior cycling stability of over 250 cycles at 1.0C (high capacity retention of 84.1% after 100 cycles at 0.5C). Furthermore, the Co3ZnC@NC-based battery can maintain a high discharge capacity of 734.0 mA h g-1 at 5.0C, along with delivering a stable reversible capacity of 805.4 mA h g-1 (∼5 mA h cm-2) after 50 cycles even under a high sulfur loading of 6.2 mg cm-2. This study affords a viable way to construct highly dispersed bimetal/carbon composites for efficient catalysts and renewable energy devices.

Highly active Co1-N3-O1 single-atom catalyst for boosting catalytic synthesis of unsaturated benzylamines and arylamines

Unsaturated benzylamines and arylamines are the key building blocks for the synthesis of organic pharmaceutical molecules, but their synthetic processes always suffer from low selectivity as a result of the excessive hydrogenation of unsaturated groups. Herein, the cobalt single-atom catalyst with an asymmetric Co1-N3-O1 structure was designed and constructed on porous carbon nanospheres. It is found that the Co1-N3-O1 catalyst showed excellent catalytic activity toward the synthesis of unsaturated benzylamines and arylamines. The results of characterization analysis and density functional theory (DFT) calculation further clarify that introducing oxygen into the Co single-atom coordination environment of Co1-N3-O1 increased hydrogenation energy barrier of the terminal C=C double bond, which is beneficial to suppress competing hydrogenation reactions. Meanwhile, the Co1-N3-O1 catalyst had the lower energy barrier for reduction of the C=N bond to amino group, boosting the yields of unsaturated benzylamines and arylamines. This study offers an attracting strategy for efficient and selective reductive amination reaction by making use of the asymmetrically structured Co single-atom catalyst.

Silica-Coated N-Doped Porous Carbon Nanospheres as Antiwear and Friction-Reduction Lubricant Additives

Silica-Coated N-Doped Porous Carbon Nanospheres as Antiwear and Friction-Reduction Lubricant Additives

In-situ pyrolysis synthesis of multi-element (F, N, S) co-doped porous carbon nanospheres as lubricating additives with improved tribological behaviors

Herein, hyper-crosslinked polystyrene nanospheres (HPSs) were synthesized via emulsion polymerization and Friedel-Crafts reaction utilizing styrene as the primary raw material. The multielement (F, N, S) co-doped carbon nanospheres with enriching microporous structures were synthesized using ionic liquid ([EMIM]NTf2) assisted carbonization of HPSs under 400 °C. The fabricated carbon nanospheres exhibit excellent dispersion stability as well as remarkable anti-friction and anti-wear properties. In comparison to pure 500SN, the friction coefficient of the multielement (F, N, S) co-doped carbon nanospheres is reduced to 0.108, resulting in 81.9 % reduction in wear volume. Furthermore, the friction coefficient shows minimal fluctuation under different frequency and temperature conditions, which is significantly lower by 21.4 % and 31.6 % respectively compared to 500SN, while exhibiting an improved carrying capacity of up to 550 N. Through Raman spectroscopy, XPS, as well as FIB-TEM analysis, the result revealed that tribochemical reactions occur between the active elements within the nanospheres and the friction pairs leading to the formation of the composite protective film (40–70 nm) composed mainly of the deposition film and the frictional chemical protective film, achieving superior frictional performance.

Superior shear-stable slippery surface of porous carbon nanospheres (PCN)-oleogel

Frictional drag reduction (DR) is of great importance in marine environments as it has the potential to significantly reduce fuel consumption, leading to both economic and environmental benefits. While various conventional DR techniques exist, many of them are energy-inefficient and require external intervention to function effectively in real marine conditions. Unlike conventional methods, bioinspired surfaces offer cost-effective and sustainable DR. However, these surfaces suffer from (i) poor durability of superhydrophobic surfaces, (ii) limited scalability, (iii) substrate dependency of coatings, and (iv) fast depletion of impregnated lubricant oil of liquid infused surfaces (LIS). In this work, we proposed a double-layered LIS oleogel surface embedded with re-entrant surface (RES) morphology by adopting spin/spray-assisted deposition processes. The RES structure, achieved by depositing porous carbon nanospheres (PCN) on the oleogel surface, effectively stabilized and replenished a large amount of lubricated oil, ensuring long-lasting lubrication. The developed PCN-oleogel surface could retain its slippery property despite exposure to harsh physical abrasion, and various chemically contaminated aqueous solutions. The developed PCN-oleogel exhibited long-term lubrication performance and shear-stable durability under high-speed, high-pressure conditions up to 15 ms−1 — such shear-stable lubrication in extremely rare in literature. Conclusively, the proposed PCN-oleogel surface is envisioned to have a great potential in achieving sustainable underwater DR in harsh marine environments.

Hierarchically Porous, N, P‐Co‐Doped Carbon Structures with Embedded Pt Particles as Effective Electrocatalysts for the Oxygen Reduction Reaction

AbstractThe proton exchange membrane fuel cell now ranks as one of the best alternatives to fossil fuels. Two optimization techniques that have stirred up a lot of controversy include reducing the amount of precious metal Pt catalysts and boosting the kinetics of the cathodic oxygen reduction reaction (ORR). Herein, “template‐etching” method is used to create N−P co‐doped low‐Pt catalysts with hierarchical porous carbon nanospheres (Pt/NPC). The P atoms′ valence electrons, which serve to attach the Pt to the equally disseminated N atoms, further disperse the Pt inside the carbon nanospheres. As a result, the Pt is able to modify the electronic structure and alter the d‐band center, which raises the intrinsic ORR activity. The hierarchical porous structure of the carbon nanospheres, created by the phytic acid activation of the pores, can expose more active sites and efficiently enhance the transfer of oxygen and electrons, increasing the catalytic efficiency. The catalysts synthesized using this method had great stability, 9.87 wt % Pt concentration, and half‐wave potential of 0.832 V for acidic intermediates and 0.855 V for alkaline intermediates. Because of its entire pH ORR catalytic capabilities, this catalyst exhibits tremendous application potential for replacing conventional Pt/C catalysts.