Hierarchical Porous Carbon Research Articles

Biological pretreatment with white rot fungi for preparing hierarchical porous carbon from Banlangen residues with high performance for supercapacitors and dye adsorption.

White rot fungi possess superior infiltrability and biodegradability on lignocellulosic substrates, allowing them to form tailored microstructures which are conducive to efficient carbonization and chemical activation. The present research employed white rot fungus pretreatment as a viable approach for preparing porous carbon from Banlangen residues. The resultant F-A-BLGR-PC prepared by pretreating Banlangen residues with white rot fungi followed by carbonization and activation has a hierarchical porous structure with a high specific surface area of 898 m2 g-1, which is 43.4% greater than that of the unprocessed sample (R-BLGR-PC). When used as an electrode for supercapacitors, the F-A-BLGR-PC demonstrated a high specific capacitance of 308 F g-1 at 0.5 A g-1 in 6 M KOH electrolyte in three-electrode configuration. Moreover, the F-A-BLGR-PC based symmetric supercapacitor device achieved a superb cyclic stability with no obvious capacitance decay after 20,000 cycles at 5 A g-1 in 1 M Na2SO4 electrolyte. Additionally, the F-A-BLGR-PC sample was found to be an ideal adsorbent for removing methyl orange (MO) from water, exhibiting an adsorption ability of 173.4 mg g-1 and a maximum removal rate of 86.6%. This study offers a promising method for the preparation of a porous carbon with a high specific surface area in a biological way using white rot fungi pretreatment, and the derived carbon can not only be applied in energy storage but also in environmental remediation, catalysis, and so on.

Ginger-derived hierarchical porous carbon as an anode material for potassium-ion batteries and capacitors

Carbonaceous materials are ideal as an anode for potassium-ion batteries (KIBs) because of their low cost, tunable physiochemical properties, and excellent reversible intercalation of potassium-ions (K+).

Solvent-free, deep eutectic system-assisted synthesis of nanoarchitectonics of hierarchical porous carbons for high rate supercapacitors

Solvent-free, deep eutectic system-assisted synthesis of hierarchical porous carbons for high rate and high energy density supercapacitors.

Tailoring a hierarchical porous carbon electrode from carbon black via 3D diatomite morphology control for enhanced electrochemical performance.

Carbon black, a nano-porous material usually derived from the pyrolysis of waste tyres possesses varied particle sizes and morphology making it a viable material for several engineering applications. However, the high tendency for CB to agglomerate remains a challenge. To address this, bio-templating has been employed to produce a nanostructured porous carbon electrode material for supercapacitor applications using diatomite as a template. Diatomite-synthesized activated carbon (DSAC) was fabricated through a three-step process involving acid treatment of diatomite, thermal activation of carbon black, and bio-template synthesis. The resulting material was thoroughly characterized using XRD, Raman spectroscopy, BET analysis, and SEM imaging. Its electrochemical properties were assessed through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The DSAC material exhibited a high specific surface area of 266.867 m2 g-1, pore volume of 0.6606 cm3 g-1, and mean pore radius of 1.8943 nm. The electrochemical evaluation revealed that DSAC demonstrates excellent electrochemical performance, achieving a high specific capacitance of 630.18 F g-1 and retaining 94.29% capacitance after 5000 cycles at 1 A g-1. The DSAC electrode is eco-friendly and a promising candidate for supercapacitor applications.

N-doped CNTs wrapped sulfur-loaded hierarchical porous carbon cathode for Li-sulfur battery studies.

Lithium-sulfur (Li-S) batteries are considered promising next-generation energy storage devices due to their low cost and high energy density (2600 W h kg-1). However, the practical applicability of Li-S batteries is hindered by the insulating nature of sulfur cathodes, and the high solubility of polysulfides (Li2Sx, 3 < x ≤ 8) which are formed during the electrochemical process. Integrating sulfur into the carbon host is an effective way to enhance the conductivity of the electrode which hampers the shuttling effect of the polysulfides. Here in this study, hierarchical porous carbon structures (HPC) are prepared from spent coffee waste (SCW) by the KOH activation process and are encapsulated with sulfur (SHPC) which increases the interaction between sulfur and carbon and enhances both the electronic and ionic conductivities. Further wrapping of SHPC with N-doped multi-walled carbon nanotubes (NCNTs) gives a SHPC-NCNT composite, which alleviates the shuttling of polysulfides by trapping them and ensures the required conductivity to the sulfur cathode during the Li+ reactions. When studied as a cathode material for Li-S batteries, the prepared cathode showed 664 and 532 mA h g-1 specific capacities after 150 cycles at 0.2C and 0.5C, respectively. The stable cyclability and rate capability properties of SPHCNCNT suggest that the prepared sulfur composite is suitable as a cathode material for Li+ energy storage applications.

Activation of biomass precursors and chemical preparation of hierarchical porous carbons for supercapacitor applications

Growing population in the world demands more accumulation of energy. Among the storage devices, capacitors have triggered enormous interest due to its excellent electrochemical characteristics. Activated carbon electrodes from Africana Duranta, Tectona Grandis, and Terminalia Catappa carbon waste, have attracted high interest because of high specific surface area and an abundant pore volume with rational micro/meso pores. The carbon black samples were prepared by a simple green synthesis with KOH treatment followed by pyrolysis method. XRD confirmed the amorphous carbon black allotrope of the carbon black respectively. The carbon obtained from the leaf, Africana Duranta showed high surface area in the range of 9.08 m²/g - 28.592 m²/g with pore radius in the range of 16.768 Å – 877.4509 Å, which was found from BJH and BET analysis respectively. Then the specific capacitance values were calculated from the CV curves using electrochemical analyzer. The highest specific capacitance value of 83.58 Fg-1 was found for Africana Duranta, which was mainly due to high surface area compared to other two leaves.

From wasted polymers to N/O co-doped partially graphitic carbon with hierarchical porous architecture as a promising cathode for high performance Zn-ion hybrid supercapacitors

N/O co-doped graphitic hierarchical porous carbon is yielded from wasted polymers. A capacity of 257.9 mA h g−1 with an ultrahigh energy density of 226.5 W h kg−1 is delivered. Excellent energy storage ability is also obtained for wearable devices.

Utilize rather than create: transforming phthalonitrile resin into N-rich hierarchical porous carbon for supercapacitor materials

Phthalonitrile (PN) resins, renowned for the highly conjugated heteroaromatic N-rich structures, are exemplary precursors for the fabrication of porous materials. However, the conventional synthesis of PN is marred by the...

Hierarchical porous carbon frameworks derived from Juncus effusus biomass with robust electromagnetic wave absorption properties

A biomass-derived electromagnetic absorber was developed using Juncus effusus (JE), achieving low RL value and broad EAB (−40.4 dB, 3.48 GHz), and the maximum RCS reduction value of 32.4 dB m2.

Heterostructure CoFe@(Co0.5Fe0.5)S@NCNT anchored on rice husk-based hierarchical porous carbon as a bifunctional cathode catalyst for Zn–air batteries

A bifunctional catalyst, characterized by its sea urchin-like morphology and multi-layer core–shell structure (CoFe@(Co0.5Fe0.5)S@NCNT), was synthesized within the restriction of RHPC' hierarchical pore structure.

Facile synthesis of O/N co-doped hierarchical porous carbon: for high performance supercapacitors and electromagnetic interference shielding

Biomass can be used to prepare carbon materials with excellent pore structures and rich surface properties based on its chemical properties, and have great potential in electrochemical energy storage and electromagnetic interference shielding.

Electronic synergy between CoP/NiCoP heterostructure and Co, Ni single atoms for efficient hydrogen evolution and overall water splitting

Transition metal phosphides (TMPs) are considered as potential electrocatalysts for hydrogen evolution (HER) and overall water splitting (OWS), but their excessively strong adsorption property toward H* limits the reaction kinetics. Herein, we design a bifunctional electrocatalyst (CoP/NiCoP/Co–Ni–N–C) supported by CoP/NiCoP heterostructure and Co, Ni single atoms, which was prepared via facile one-pot pyrolysis process. The interfacial electronic synergy between the high-electropositive Co–N–C, Ni–N–C and the electron-rich CoP/NiCoP heterostructure balanced the hydrogen binding strength, resulting in fast kinetics and high intrinsic activity. Besides, the g-C3N4 was applied as a self-sacrificial template to construct the N doped hierarchical porous carbon carrier, which provided abundant mass transfer pathways and enhanced the charge transfer efficiency. Additionally, the fluid catalytic cracking (FCC) slurry was intelligently applied as extra carbon source, which not only limited the size of CoP/NiCoP nanoparticles, but also increased the loading of Co and Ni single atoms. Benefit from those advantages, the optimized CoP/NiCoP/Co–Ni–N–C exhibited low overpotentials of 40 mV at 10 mA cm−2 toward HER in 1 M KOH. Meanwhile, the two-electrode system only need 1.54 V to achieve the current density of 10 mA cm−2. This work provided a kind of potential electrocatalyst for efficient water splitting and a method for low-cost catalyst design.

Novel hydrophobic hierarchical porous carbon from sewage sludge for the efficient capture of gaseous iodine

Finding an inexpensive and efficient porous adsorbent to capture the gaseous radioiodine generated during spent fuel reprocessing has been challenging. Herein, we present a design philosophy for waste control to develop porous carbon for gaseous iodine capture from sewage sludge waste. Among them, the novel in situ etching of polytetrafluoroethylene was employed to improve pore accessibility. The hazards of the conventional preparation of sludge-derived carbon using highly corrosive NaOH and HF solutions were overcome. Polytetrafluoroethylene etched porous carbon with large specific surface area (1103 m2/g), interconnected hierarchical porous structure, and excellent hydrophobicity (water contact angle 126.52°), providing efficient adsorption of gaseous iodine in hot (30–150 °C) and humid (50–96% relative humidity [RH]) environments. The iodine adsorption of hierarchical porous carbon was tested under static and dynamic conditions, and high records have been achieved. Notably, due to the structural advantage of hydrophobicity, a considerable dynamic adsorption capacity (1746.77 mg/g) was also maintained in a mixed iodine gas stream containing water vapor in a humid (50% RH) hot (75 °C) condition. This study is the first to use an in situ etching strategy for polytetrafluoroethylene, which opens a new avenue for converting sludge waste into low-cost porous carbon and provides an attractive option for capturing iodine in hot and humid environments.

Scalable synthesis of N, O co-doped hierarchical porous carbon for high energy density supercapacitors

Rational design of hierarchical porous architecture with abundant pseudocapacitive sites is highly desirable for carbon electrode materials. However, the lengthy production process and high economic input limit its broader application. Herein, we successfully prepared N, O co-doped hierarchical porous carbon (NOHC) through hydrothermal carbonization (HTC) of chitin biomass with the assist of NH4Cl and subsequent carbonization with NaNH2. The optimal NOHC600 exhibits a remarkable hierarchical porous structure and an ultrahigh specific surface area (SSA) of 2555 m2 g−1. Furthermore, it showcases a significant content of N, O co-doping, thereby providing abundant defects and additional active sites for ion adsorption. The aforementioned characteristics ensure outstanding capacitance performance of NOHC600. In the three-electrode system, NOHC600 exhibits a remarkable specific capacitance of up to 455 F g−1 at a current density of 0.5 A g-1. The symmetric supercapacitors (SCs) based on NOHC600 achieve an impressive energy density of 30.4 Wh kg−1 at a power density of 180 W kg−1. Moreover, the all-solid-state NOHC600 microsupercapacitors (MSCs) demonstrate an exceptional areal capacitance of 78.2 mF cm−2 and an areal energy density of up to 10.8 μWh cm−2. Accordingly, this facile and scalable strategy shows a great potential for producing high-heteroatom-doped porous carbon materials from chitin biomass, which can be applied in practical energy-related applications.

Converting bio-waste rice into ultralight hierarchical porous carbon to pack polyethylene glycol for multifunctional applications: Experiment and molecular dynamics simulations

A structural-functional integrated shape-stabilized composite phase change material (PCM) was synthesized by converting biowaste rice into ultralight (0.08 g/cm3) hierarchical porous carbon (CNR) to pack polyethylene glycol (PEG) PCM. The thermal property and corresponding mechanism were analyzed. The results show that the composite PCM exhibits excellent thermal storage efficiency (93.3 %), considerable solar photothermal conversion efficiency and superior thermal stability. The interfacial thermal resistance (ITR) of PEG/CNR is 73 % lower than graphene foam-based composite PCM thus a fast transient temperature response. Particularly, the package of PEG endowed composite PCM with elastic characteristic thereby an enhanced compressive strength. Furthermore, covering PEG/CNR results in a delay of approximately 1.3 times in reaching the peak temperature on the surface of electronic components, and a delay of 5 times in cooling time. This study presents solid guidelines for societal development that is sustainable and makes some recommendations for construction of composite PCMs combining multifunctional applications.

Synthesis of Bi2O3/hierarchical porous carbon composites for supercapacitor application

Bismuth oxide (Bi2O3) is considered a promising electrode material for supercapacitors boasting a high theoretical capacity. Its weak conductivity, limited rate performance, and poor cycling stability have significantly hindered practical applications. In this work, a simple precipitation and calcination method was used to prepare Bi2O3/hierarchical porous carbon composite materials (Bi2O3/N-HPC). The biomass-derived hierarchical porous carbon precursor was prepared through a process involving nitrogen doping and chemical activation. Comprehensive physical and chemical structure characterization results showed that a large number of spherical Bi2O3 particles were dispersed on the surface of the carbon material, providing numerous active sites for electrochemical reactions. The nitrogen-doped hierarchical porous carbon scaffold provided rapid pathways for charge transfer and restricted the aggregation of Bi2O3 particles. As an electrode material in a 6 M KOH electrolyte, Bi2O3/N-HPC exhibited a specific capacitance of 684.9 F g−1 at a current density of 0.5 A g−1, and even at an increased current density of 20 A g−1, the specific capacitance remained at 500.0 F g−1. After 10,000 cycles of charge and discharge, the capacitance retention rate of the Bi2O3/N-HPC electrode reached 85.2 %. This research offers a promising pathway for the development of high-performance supercapacitor electrode materials.

π-Conjugated molecule mediated self-doped hierarchical porous carbons via self-stacking interaction for high-energy and ultra-stable zinc-ion hybrid capacitors

Understanding the self-stacking interactions in precursors can facilitate the preparation of high-performance carbon materials and promote the commercial application of zinc ion hybrid capacitors (ZIHCs). Here, a π-conjugated molecule mediated pyrolysis strategy is presented to prepare carbon materials. Taking intermolecular force simulation (reduced density gradient plots) as a guide, the relationship between the self-stacking interactions in π-conjugated molecules and the structural parameters of carbon materials can be extrapolated. The resultant self-doped hierarchical porous carbons (NHPCs) derived from 1, 8, 4, 5-naphthalenetetracarboxdiimide with suitable self-stacking interactions empower the highest specific surface areas (2038 m2/g) and surface opening macropores. The NHPCs-based ZIHCs deliver a high capacity of 220 mAh/g, a high energy density of 149.5 Wh kg−1 and a super-stable cycle lifespan with 93.2 % capacity retention after 200, 000 cycles. The excellent electrochemical performance roots in the superior hierarchical porous structure with surface opening macropores, which guarantees the structural stability of carbon cathodes upon repeated rounds. Meanwhile, the heteroatom doping further relieves the kinetics concern of Zn2+ uptake/removal to enhance O-Zn-N binding particularly at high discharge currents. Besides, the proton-assisted Zn2+ dual-ion storage mechanism plays an essential role in the energy storage process. This work demonstrates a facile synthesis method and advances the fundamental understanding of its dual-ion storage mechanism.

Orange peel derived hierarchical porous carbon/sulfur composite cathode material for Li–S battery

A hierarchical porous carbon (HPC) structure was developed from the waste orange peel using KOH as an activating agent. In HPC, the carbon has interconnected hierarchical pores size of which lies between 2 nm and 5 μm. HPC/S composite was prepared by melt-diffusion method and analysed for electrochemical performance. HPC/S exhibits a high initial discharge capacity of 870 mAhg−1 at 0.2C and 734 mAhg−1 at 0.4C. The Carbon-black (CB)/Sulfur (S) composite was also prepared and characterized. A comparative study was done with the CB/S composite, which shows poor cyclability and a discharge capacity of 332 mAhg−1 at 0.2C rate considering 1C = 1672 mAhg−1. Sulfur confinement in the HPC structure leads to superior electrochemical performance of the HPC/S composite ensuring a promising cathode material.

Coordination polymer and layered double hydroxide dual-precursors derived polymetallic phosphides confined in N-doped hierarchical porous carbon nanoflower as a highly efficient bifunctional electrocatalyst for overall water splitting

Controllable construction of proficient electrocatalyst with 3D hierarchical architecture to achieve low cost and high efficient overall water splitting is of great significance to the sustainable development. Hereby, trimetallic phosphides confined in N-doped carbon nanoflowers (CoNiP/CoNiFeP@NCNFs) were fabricated using CoNi coordination polymer nanoflowers/CoNiFe layered double hydroxide (CoNi CPNFs/CoNiFe LDH) as precursors followed by phosphorization. Benefiting from the unique 3D hierarchical porous architecture, preeminent conductivity, high specific surface area, efficient mass/charge transfer and synergic effect of various transition metals, the well-designed CoNiP/CoNiFeP@NCNFs exhibit extraordinary electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media. Particularly, this novel material can work as a bifunctional catalyst in an integrated water-splitting electrolyzer, which only requires a low voltage of 1.55 V to realize the current density of 10 mA cm−2 with admirable durability (at least 28 h). This work certified the foreground of composites assembled by 3D hierarchical porous carbon and polymetallic phosphides for overall water splitting. It also provided a novel proposal for the rational designing and constructing highly active electrocatalysts by using coordination polymer and LDH as dual-precursors.

Undaria pinnatifida (wakame)-derived Fe, N co-doped graphene-like hierarchical porous carbon as highly efficient catalyst for activation of peroxymonosulfate (PMS) toward degradation of tetracycline (TC)

The use of biomass as a catalyst offers a cost-effective and efficient approach for various processes, including the activation of peroxymonosulfate (PMS) to degrade contaminants. In this study, we successfully obtained Fe and N co-doped graphene-like hierarchical porous structure carbon (Fe-N/BC) by using undaria pinnatifida (wakame) as the precursor. The Fe-N/BC catalyst was utilized to activate PMS and degrade tetracycline (TC). Characterization results demonstrated an even distribution of Fe and N on the surface of the porous structure carbon. Compared to BC@PMS and N/BC@PMS, the Fe-N/BC@PMS system exhibited excellent degradation performance, achieving an 83.9 % degradation of TC in just 5 min with an ultralow catalyst dosage (Ca = 0.05 g/L) and a high TC concentration (TC = 0.03 g/L). Furthermore, experiments on radicals quenching and electron paramagnetic resonance (EPR) analysis indicated that singlet oxygen (1O2), a non-radical species, was demonstrated as the primary reactive oxygen species (ROS). The degradation mechanical analysis suggested that zero-valent iron (Fe0), pyridinic N, graphitic N, and Fe-Nx in the Fe-N/BC were the reason for the high catalytic activity. Moreover, the degradation pathways of TC were suggested through the use of LC-MS. Additionally, the ECOSAR system was employed to assess the toxicity of the intermediate products. This study reveals the active site and its mechanism in Fe-N composite biocarbon catalysts, providing a new method for synthesizing algal biocarbon catalysts.