Three-dimensional Hierarchical Porous Carbon Research Articles

Green one-pot synthesis of spongy hierarchical porous carbon with interconnected channels towards high-performance supercapacitors

Green and convenient construction of three-dimensional (3D) hierarchical porous carbon for supercapacitors (SCs) has drawn widespread attention due to their effective ion adsorption and transport capabilities. In this study, sucrose-derived spongy hierarchical porous carbon materials were successfully prepared using a one-step carbonization process with sodium chloride and sodium bicarbonate acting as collaborative pore-forming agents. The optimal carbon material exhibits a distinct 3D spongy structure with interconnected channels, high specific surface area, and proper pore size distribution. Consequently, it displays a specific capacitance of 263.5 F g−1 at 0.5 A g−1 and could retain 221.9 F g−1 (84.21%) at 20 A g−1. Additionally, the as-fabricated device delivers a supreme energy density of 17.0 Wh kg−1 at 80 W kg−1 and possesses exceptional cycling stability of 94.36% after 20000 cycles. Through the combination of raw material carbonization properties and synergistic pore-making mechanisms, the present work provides an effective and eco-friendly approach for fabricating 3D spongy hierarchical porous carbon materials with interconnected channels for high-performance SCs.

Production of Lignin-Derived Functional Material for Efficient Electromagnetic Wave Absorption with an Ultralow Filler Ratio.

Industrial lignin, a by-product of pulping for papermaking fibers or of second-generation ethanol production, is primarily served as a low-grade combustible energy source. The fabrication of high-value-added functional materials with industrial lignin is still a challenge. Herein, a three-dimensional hierarchical lignin-derived porous carbon (HLPC) was prepared with lignosulfonate as the carbon source and MgCO3 as the template. The uniform mixing of precursor and template agent resulted in the construction of a three-dimensional hierarchical porous structure. HLPC presented excellent electromagnetic wave (EMW) absorption performance. With a low filler content of 7 wt%, HLPC showed a minimum reflection loss (RL) value of -41.8 dB (1.7 mm, 13.8 GHz), and a maximum effective absorption bandwidth (EAB) of 4.53 GHz (1.6 mm). In addition, the enhancement mechanism of HLPC for EMW absorption was also explored through comparing the morphology and electromagnetic parameters of lignin-derived carbon (LC) and lignin-derived porous carbon (LPC). The three-dimensional hierarchical porous structure endowed the carbon with a high pore volume, resulting in an abundant gas-solid interface between air and carbon for interfacial polarization. This structure also provided conductive networks for conduction loss. This work offers a strategy to synthesize biomass-based carbon for high-performance EMW absorption.

Polyacrylonitrile-sodium lignosulfonate -derived nitrogen-doped three-dimensional hierarchical porous carbon for supercapacitors

Modulation of pore structure and heteroatom doping are very important strategies to improve the electrochemical properties of carbon electrode materials. This report investigates the use of biomass-derived nitrogen-doped porous carbon materials to address the challenge of the specific capacitance and energy density in supercapacitors. Nitrogen-doped three-dimensional hierarchical porous carbon materials were prepared using a polyacrylonitrile/sodium lignosulfonate composite monolith as a precursor by thermally induced phase separation and subsequent carbonization/activation. This method precisely controls the structure and surface properties of porous carbon materials by regulating the structure of the precursor and situ doping of nitrogen, which is a valuable strategy for the controllable regulation of the pore structure for nitrogen-doped porous carbon materials. The resulting carbon material displayed excellent capacitance performance, exhibiting a high specific capacitance of 325.7F g -1 at a current density of 0.5 A/g, maintaining initial capacitance retention of 90.1 % at a current density of 5 A/g after 10,000 cycles. When investigated for practical applications, the assembled supercapacitor device had a higher energy density (9.88 W h kg- 1), which is higher than commercial carbon-based supercapacitors.

Nitrogen-doped oxygen-rich porous carbon framework towards aqueous zinc ion hybrid capacitors and zinc-iodine batteries

Zinc ion hybrid capacitors (ZIHCs) and zinc-iodine batteries (ZIBs) have attracted significant attention as promising components for large-scale energy storage owing to their excellent security, environmental friendness and high theoretical capacity of Zn anode. However, there still exist some respective obstacles for commercial applications, such as limited specific capacity, poor cycling stability of ZIHCs or shuttle effect of polyiodide of ZIBs. Here, to enhance electrochemical properties, we report a synergistic one-step activation strategy using KMnO4 and Zn(NO3)2 for nitrogen-doped oxygen-rich three-dimensional hierarchical porous carbon (NOPC). Benefiting from its high specific surface area, three-dimensional porous morphology and improved redox sites from heteroatom doping, the as obtained NOPC exhibits desired electrochemical performance as cathode for ZIHCs and ZIBs. The NOPC-based electrode achieves an ultra-high specific capacity of 230 mAh g−1 at 0.1 A g−1, and 118 mAh g−1 can be maintained at 10 A g−1. Besides, a distinguished energy density of 213.0 Wh kg−1 and a high-power density of 11.2 kW kg−1 are also achieved with a constructed ZIHCs device. Furthermore, the NOPC/I2 composite exhibited excellent rate performance (54 mAh g−1 at 10 A g−1) and cycling performance (∼88.3 % retention upon 5000 cycles) in ZIBs device. This work provides a facile but effective strategy to develop 3D porous electrodes for ZIHCs and ZIBs with remarkable rate and cycling performance.

Three-dimensional graphitic hierarchical porous carbon-supported SnOx@nitrogen-doped carbon composite as high-performance lithium ion battery anode material

Utilizing tin and its oxides (SnOx, x = 0/1/2) as anode confront the main problems like large volume expansion and poor electrical conductivity during cycling. As an efficient solution, a three-dimensional (3D) graphitic hierarchical porous carbon (HPC) with highly fluffy structure was employed as a support for fabrication of HPC/SnOx@nitrogen-doped carbon (NC) composite. The resulting HPC/SnOx@NC composite presented an effective dual‑carbon confinement structure with 3D conductive network and high-quality carbon coatings. The unique structure played significant roles in restricting the expansion of Sn and its oxides as well as enhancing their ion/electron transport efficiency. The as-prepared composite exhibited a maintained reversible specific capacity of 644 mAh g−1 after 200 cycles at 1000 mA g−1. In addition, it presented a high specific capacity of 1458 mAh g−1 at 100 mA g−1 and 858 mAh g−1 at 5000 mA g−1 (58.8 % capacitance retention), and meanwhile showed a remarkable cycling stability with a high capacity retention of 63 % (333 mAh g−1) after 850 cycles at 5000 mA g−1. Therefore, the HPC/SnOx@NC composite has the potential to be a new generation of LIBs anode.

Three-dimensional hierarchical porous carbon surface-decorated graphitic carbon foam/stearic acid composite as high-performance shape-stabilized phase change material with desirable photothermal conversion efficiency

To simultaneously improve the photothermal conversion and encapsulation capacity of phase change material (PCM), a three-dimensional hierarchical porous carbon surface-decorated graphitic carbon foam (SGF) was developed. Employing this SGF as an encapsulated skeleton for stearic acid (SA), a unique shape-stabilized SA/SGF composite PCM was successfully prepared after vacuum impregnation. The porous carbon surface exhibits a uniform and fluffy three-dimensional continuous network structure well adhered onto the pore walls of the SGF; it can act as a desirable interfacial layer between SA and the SGF, which gives the composite effective encapsulation performance and good interfacial compatibility. The as-prepared composite has a loading capacity of 78.16% for melted SA without any leakage, and possesses a thermal conductivity of 3.25 W/mK with 1377% higher than that of SA and a compressive strength of 4.41 MPa (increasing 283.5% than the SGF). Further, the melting and crystallization enthalpy of the composite reaches 167.6 J/g and 167.5 J/g, respectively, with a thermal storage efficiency of up to 95.13%; meanwhile, it displays excellent thermal cycle stability revealed by keeping an enthalpy of 92.80% after 200 thermal cycles. More importantly, it presents a high photothermal conversion of 90.14% at 200 mW/cm2 with the ability to serve as a stable heat source during solar-thermal-electric conversion. Consequently, the composite has great potential in solar storage and waste heat recycle.

Hierarchically Porous Carbon Nanosheets from One-Step Carbonization of Zinc Gluconate for High-Performance Supercapacitors.

Supercapacitors, with high energy density, rapid charge-discharge capabilities, and long cycling ability, have gained favor among many researchers. However, the universality of high-performance carbon-based electrodes is often constrained by their complex fabrication methods. In this study, the common industrial materials, zinc gluconate and ammonium chloride, are uniformly mixed and subjected to a one-step carbonization strategy to prepare three-dimensional hierarchical porous carbon materials with high specific surface area and suitable nitrogen doping. The results show that a specific capacitance of 221 F g-1 is achieved at a current density of 1 A g-1. The assembled symmetrical supercapacitor achieves a high energy density of 17 Wh kg-1, and after 50,000 cycles at a current density of 50 A g-1, it retains 82% of its initial capacitance. Moreover, the operating voltage window of the symmetrical device can be easily expanded to 2.5 V when using Et4NBF4 as the electrolyte, resulting in a maximum energy density of up to 153 Wh kg-1, and retaining 85.03% of the initial specific capacitance after 10,000 cycles. This method, using common industrial materials as raw materials, provides ideas for the simple preparation of high-performance carbon materials and also provides a promising method for the large-scale production of highly porous carbons.

Design and preparation of hierarchical porous carbon-based materials with bionic “ant nest” structure for high performance asymmetric supercapacitors

Rational design of electrodes to broaden the working potential window is an attractive approach to improve the energy density of asymmetric supercapacitors. Herein, a simple non-solvent-induced phase separation method was used to construct a bionic "ant nest" three-dimensional hierarchical porous carbon (HPC) without any template, realizing a three-dimensional interlaced interconnection network structure similar to that of a natural ant nest, which adsorbs more ions through a larger accessible area and facilitates the bi-continuous transport of ions and electrons. Further, the aqueous asymmetric supercapacitor assembled with MnO2-modified HPC (HPC/MnO2) as the positive electrode and nitrogen-doped HPC (NHPC) as the negative electrode has an energy density as high as 21 Wh kg−1 at a power density of 410 W kg−1, and as high as 17 Wh kg−1 even at a power density of 13 kW kg−1. The device exhibits an excellent electrochemical performance over a potential window of 0–1.6 V.

Facile fabrication of core-shell α-Fe2O3@PPy imbedded into porous biomass-derived carbon for enhanced lithium storage

Due to the large theoretical capacity (1007mAh/g) and unique electrochemical properties, α-Fe2O3 is regarded as an improved anode for next generation lithium-ion batteries (LIBs). Nevertheless, its numerous applications in lithium storage are constrained by its weak conductivity and large volume variation during cycling. Herein, the unique BPC/α-Fe2O3@PPy composite is synthesized by incorporating α-Fe2O3@PPy into three-dimensional hierarchical porous carbon, which can enhance charge transfer efficiency and decrease its volume variation. As anodes for LIBs, the BPC/α-Fe2O3@PPy electrode displays excellent cycle stability and exceptional high-rate performance. This work offers a sustainable approach of constructing economic and green α-Fe2O3-based composite as novel LIBs anode materials for renewable applications.

High nitrogen-oxygen dual-doped three-dimensional hierarchical porous carbon network derived from Eriocheir sinensis for advanced supercapacitors

High nitrogen-oxygen dual-doped three-dimensional hierarchical porous carbon network derived from Eriocheir sinensis for advanced supercapacitors

Synthesis of CoP@B,N,P co-doped porous carbon by a supramolecular gel self-assembly method for lithium-sulfur battery separator modification.

Lithium-sulfur batteries (LSBs) are regarded as promising next-generation batteries due to their high abundance and high theoretical energy density. However, the commercial application of LSBs is hindered by the shuttle effect of soluble lithium polysulfides (LiPSs). Hence, we synthesised B, N, P co-doped three-dimensional hierarchical porous carbon materials, uniformly dispersed with CoP nanoparticles, and utilized them as the coating material for the PE separator. The catalytic and adsorption capacity of the composite material was significantly enhanced by CoP. Both experimental and theoretical calculations show that the LiPS adsorption capacity of the composite material is significantly enhanced after the introduction of B atoms. As a result, the assembled LSBs with the CoP@BNPC/PE separator show excellent long-term stability (940.8 mA h g-1 after 500 cycles at 1.0 C, and only a 0.026% decay rate per cycle) and superior rate performance (613.6 mA h g-1 at 5.0 C). Our work further proves that a modified separator is an effective strategy to promote the commercialization of LSBs.

Three-Dimensional Hierarchical Seaweed-Derived Carbonaceous Network with Designed g-C3N4 Nanosheets: Preparation and Mechanism Insight for 4-Nitrophenol Photoreduction.

The development of g-C3N4-based photocatalysts with abundant active sites is of great significance for photocatalytic reactions. Herein, a smart and robust strategy was presented to fabricate three-dimensional (3D) g-C3N4 nanosheet-coated alginate-based hierarchical porous carbon (g-C3N4@HPC), including coating melamine on calcium alginate (CA) hydrogel beads, freeze-drying hydrogel beads as well as pyrolysis at high temperatures. The resulting photocatalyst possessed a significantly high surface area and a large amount of interconnected macropores compared with porous carbon without the melamine coating. The unique structural features could effectively inhibit the curling and agglomeration of g-C3N4 nanosheets, provide abundant photocatalytic active sites, and promote mass diffusion. Therefore, the g-C3N4@HPC composite exhibited remarkable photocatalytic activity and outstanding stability toward the photoreduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 under natural sunlight and simulated visible-light irradiation (λ > 420 nm) using a 300 W xenon lamp. Moreover, the mechanism toward the photocatalytic reaction was extensively studied by quenching experiments and electron spin resonance (ESR) experiments. The results showed that active hydrogen species were able to be achieved by following a dual-channel pathway in the NaBH4 system, which included photocatalytic reduction of H+ ions and photocatalytic oxidation of BH4- ions. This work not only opens up a new way to design efficient photocatalysts for various reactions but also provides a reference for an in-depth study of the photoreduction mechanism.

The Scalable Solid-State Synthesis of a Ni5P4/Ni2P-FeNi Alloy Encapsulated into a Hierarchical Porous Carbon Framework for Efficient Oxygen Evolution Reactions.

The exploration of high-performance and low-cost electrocatalysts towards the oxygen evolution reaction (OER) is essential for large-scale water/seawater splitting. Herein, we develop a strategy involving the in situ generation of a template and pore-former to encapsulate a Ni5P4/Ni2P heterojunction and dispersive FeNi alloy hybrid particles into a three-dimensional hierarchical porous graphitic carbon framework (labeled as Ni5P4/Ni2P–FeNi@C) via a room-temperature solid-state grinding and sodium-carbonate-assisted pyrolysis method. The synergistic effect of the components and the architecture provides a large surface area with a sufficient number of active sites and a hierarchical porous pathway for efficient electron transfer and mass diffusion. Furthermore, a graphitic carbon coating layer restrains the corrosion of alloy particles to boost the long-term durability of the catalyst. Consequently, the Ni5P4/Ni2P–FeNi@C catalyst exhibits extraordinary OER activity with a low overpotential of 242 mV (10 mA cm−2), outperforming the commercial RuO2 catalyst in 1 M KOH. Meanwhile, a scale-up of the Ni5P4/Ni2P–FeNi@C catalyst created by a ball-milling method displays a similar level of activity to the above grinding method. In 1 M KOH + seawater electrolyte, Ni5P4/Ni2P–FeNi@C also displays excellent stability; it can continuously operate for 160 h with a negligible potential increase of 2 mV. This work may provide a new avenue for facile mass production of an efficient electrocatalyst for water/seawater splitting and diverse other applications.

Nanocrystal co-existed highly dense atomically disperse Pt@3D-hierarchical porous carbon electrocatalysts for tri-iodide and oxygen reduction reactions

The fabrication of highly dense atomically dispersed platinum (Pt) on a carbon matrix increases the catalytic sites and is one of the ways to utilize Pt to make inexpensive and highly efficient electrocatalysts. We have employed a three-dimensional hierarchical porous carbon (3D-HPC) substrate and nanocrystal co-existed highly dense Pt single atoms deposited by the incipient wetness impregnation method. The special structure of the 3D-HPC substrate favors the homogeneous dispersion of Pt all over the 3D-HPC, leading to nanocrystal co-existed highly dense atomically disperse Pt@3D-HPC. The as-prepared Pt@3D-HPC shows outstanding catalytic properties towards tri-iodide and oxygen reduction reactions (ORR). The Pt@3D-HPC electrode shows lower charge transfer resistance (Rct) at the electrode/electrolyte interface with narrow peak-to-peak separation (△Epp) and higher peak current density during the tri-iodide reduction reaction (IRR). The DSSC fabricated with a Pt@3D-HPC electrode shows improved performance compared to the reference Pt counter electrode (CE). Furthermore, CV and LSV demonstrate the better catalytic activity of Pt@3D-HPC towards ORR, with higher onset potential (Eonset), half-wave potential (E1/2), and current density (j) compared to the reference 20% Pt/C electrode. Furthermore, impressive mass activity was observed by the Pt@3D-HPC catalyst compared to 20% Pt/C and other recently reported single atom-based catalysts. The Pt@3D-HPC catalyst also shows improved stability towards IRR and ORR. This simple strategy to fabricate nanocrystal co-existed highly disperse Pt@3D-HPC catalysts with outstanding electrocatalytic performance and stability paves the way for its practical application and provides insights into a new approach to the design of electrocatalysts applicable to energy-related devices.

Form-Stable phase change composites based on porous carbon derived from polyacrylonitrile hydrogel

Three-dimensional hierarchical porous carbon (3D-HPC) carriers were fabricated by pyrolyzing porous polyacrylonitrile hydrogels at high temperature, which were further applied to achieve simultaneous guarantee of the high energy storage density, thermal conductivity, shape stability and optical/electric-thermal energy conversion performance of PCMs. • Synthesis of PAN gels is green and facile; AMPS helps polymerization and pyrolysis. • Carbonization of PAN aerogel produces high-performance 3D-HPC carriers. • 3D-HPC can load PEG > 85 wt% with shape stability and thermal cycling stability. • 3D-HPC/PEG CPCMs present 10 times increase in thermal conductivity than PEG. • CPCMs possess optical/electric-thermal energy conversion capability. How to improve thermal conductivity as well as energy conversion efficiencies and to prevent melting leakage of solid–liquid phase change materials (PCMs) has been the essential challenges for the development of energy storage technology for storing a tremendous amount of waste heat and renewable and sustainable solar energy. Here, we reported the fabrication of high-performance form-stable composite PCMs (CPCMs) using the thermal conductive 3D-HPC carriers produced from the pyrolysis of porous polyacrylonitrile (PAN) copolymer hydrogels to confine the polyethylene glycol (PEG) PCMs. The porous 3D network PAN gel templates generate hierarchical cavities with micro/mesopores on the skeleton after pyrolysis which provides more space as well as the capillary adsorption and chemical interaction for the storage of PEG PCMs. The 3D-HPC/PEG CPCMs show high energy storage density (as high as 173.5 J g −1 ), high phase transformation efficiency and excellent thermal cycle stability. The carbon scaffold highly enhanced the thermal conductivity of CPCMs ∼ 10 times of the pure PEG and ensured its optical/electric-thermal energy conversion performance. This study demonstrates a facile, efficient and green way to fabricate hierarchical porous carbon with controllable porosity and degree of graphitization for improving the energy storage density, thermal conductivity, shape stability and energy conversion performance of PCMs.

Hydrothermal synthesis of 3D hierarchical ordered porous carbon from yam biowastes for enhanced supercapacitor performance

Through simple treatment of biowastes to obtain carbon materials with hierarchical ordered porous structure and prominent specific capacity has received increasing attention. Herein, novel uniform three-dimensional (3D) hierarchical porous carbon was generated by a low-cost and facile hydrothermal carbonization and chemical activation process from yam biowastes. Specially, the derived uniform 3D hierarchical carbon demonstrates an ultra-high specific capacity of 556.0 F·g−1 at 0.5 A·g−1 and a superior cycle stability with a capacitance retention of 94.7 % after 10,000 cycles at 10 A·g−1 in 6 M KOH. Moreover, the assembled symmetrical supercapacitor provides an outstanding energy density of 45.5 Wh·kg−1 if the specific power was 200.0 W·kg−1 in 1 M Na2SO4 electrolyte. The encouraging results presented herein make the 3D hierarchical ordered porous carbon immensely promising for supercapacitors with good property.

Preparation and characterization of three-dimensional hierarchical porous carbon from low-rank coal by hydrothermal carbonization for efficient iodine removal.

Low-rank coal, such as Shengli lignite (SL) and Datong bitumite (DT), has abundant reserves and is low in cost. Due to its high moisture content, abundant oxygen-containing groups, high ash content and low calorific value, low-rank coal is mainly used in a low-cost method of direct combustion. For better value-added utilization of SL and DT, a novel strategy has been developed for the preparation of oxygen-rich hierarchical porous carbons (HPCs) by hydrothermal carbonization (HTC), followed by steam activation. In this paper, firstly, the physical and chemical properties of SL and DT were improved by HTC pretreatment, bringing them closer to high rank coal. Then, the effects of HTC pretreatment and activation temperature on the properties of the HPCs were investigated in detail. The results show that the HPCs have mainly microporous structures (the microporosity of 200-SLHPC-900 is 79.58%) based on the N2 adsorption–desorption isotherm analysis and exhibit a higher specific surface area (SSA) and larger pore volume (25.02% and 2.69% improvement for 200-SLHPC-900; 4.93% and 14.25% increase for 200-DTHPC-900, respectively) after HTC pretreatment. The two types of HPCs also present good adsorption performance. The iodine adsorption value of lignite-based HPC presents an increase of 13.72% from 503 mg g−1 to 572 mg g−1, while the value of bitumite-based HPC increases up to 924 mg g−1. A preliminary additional HTC step is therefore an effective method by which to promote the performance of low-rank coal based porous carbon. The process of hydrothermal carbonization and steam activation is a cost-effective and environmentally-friendly preparation method, which omits the use of a chemical activator and reduces the step of alkaline waste liquid discharge compared with the route of carbonization and chemical activation.

High performance lithium-sulfur batteries using three-dimensional hierarchical porous carbons to host the sulfur

High performance lithium-sulfur batteries using three-dimensional hierarchical porous carbons to host the sulfur

Three-Dimensional Hierarchical Porous Carbons Derived from Betelnut Shells for Supercapacitor Electrodes.

Electrochemical energy storage (EES) systems are attracting research attention as an alternative to fossil fuels. Advances in the design and composition of energy storage materials are particularly significant. Biomass waste-derived porous carbons are particularly suitable for use in EES systems as they are capable of tuning pore networks from hierarchical porous structures with high specific surface areas. These materials are also more sustainable and environmentally friendly and less toxic and corrosive than other energy storage materials. In this study, we report the creation of a three-dimensional hierarchical porous carbon material derived from betelnut shells. The synthesized three-dimensional (3D) hierarchical porous carbon electrode showed a specific capacitance of 290 F g−1 using 1 M KOH as an electrolyte at a current density of 1 A g−1 in three-electrode systems. Moreover, it offered a high charge/discharge stability of 94% over 5000 charge–discharge cycles at a current density of 5 A g−1. Two-electrode symmetric systems show a specific capacitance of 148 F g−1, good cyclic stability of 90. 8% for 5000 charge-discharge cycles, and high energy density of 41 Wh Kg−1 at the power density of 483 W Kg−1 in aqueous electrolyte.

High performance lithium-sulfur batteries using threedimensional hierarchical porous carbons to host the sulfur

Lithium-sulfur batteries are promising for future energy storage because of their high-energy density and low price. However, they have many problems, especially the large volume change during cycling and the shuttle effect of the soluble polysulfides. To solve these problems, a three-dimensional hierarchical porous carbon (3D-HPC) was investigated as the sulfur host of a lithium-sulfur battery. The 3D-HPC was prepared by a template method using polymethyl methacrylate and zinc oxide as the templates to form mesopores and macropores, respectively. The results showed that the interconnected macroporous channels and abundant large mesopores formed a three-dimensional conductive carbon network which is beneficial for electron/ion transfer and relieves the cathode volume change by the physical limiting effect. The pores alleviate the shuttle effect by the capillary condensation. A 3D-HPC-S composite used as the cathode has excellent electrochemical properties. The first discharge specific capacity of the 3D-HPC-S is 1314.6 mAh g−1 at 0.2 C with a sulfur loading of 70%. After 100 cycles, the capacity retention rate is 69.13%. At 0.5 C, the capacity retention rate after 200 cycles is 59.02% and the average coulombic efficiency is 98.16%.