Application Of Porous Carbon Materials Research Articles

Pore structure and oxygen content design of amorphous carbon toward a durable anode for potassium/sodium‐ion batteries

AbstractBoth sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) are considered as promising candidates in grid‐level energy storage devices. Unfortunately, the larger ionic radii of K+ and Na+ induce poor diffusion kinetics and cycling stability of carbon anode materials. Pore structure regulation is an ideal strategy to promote the diffusion kinetics and cyclic stability of carbon materials by facilitating electrolyte infiltration, increasing the transport channels, and alleviating the volume change. However, traditional pore‐forming agent‐assisted methods considerably increase the difficulty of synthesis and limit practical applications of porous carbon materials. Herein, porous carbon materials (Ca‐PC/Na‐PC/K‐PC) with different pore structures have been prepared with gluconates as the precursors, and the amorphous structure, abundant micropores, and oxygen‐doping active sites endow the Ca‐PC anode with excellent potassium and sodium storage performance. For PIBs, the capacitive contribution ratio of Ca‐PC is 82% at 5.0 mV s−1 due to the introduction of micropores and high oxygen‐doping content, while a high reversible capacity of 121.4 mAh g−1 can be reached at 5 A g−1 after 2000 cycles. For SIBs, stable sodium storage capacity of 101.4 mAh g−1 can be achieved at 2 A g−1 after 8000 cycles with a very low decay rate of 0.65% for per cycle. This work may provide an avenue for the application of porous carbon materials in the energy storage field.

Merging polymers of intrinsic microporosity and porous carbon-based zinc oxide composites in novel mixed matrix membranes for efficient gas separation

Mixed matrix membranes (MMMs) have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers. However, achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge, due to the difficulty of achieving an optimal match between polymers and fillers. In this study, we incorporate a porous carbon-based zinc oxide composite (C@ZnO) into high-permeability polymers of intrinsic microporosity (PIMs) to fabricate MMMs. The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility, mitigating the formation of non-selective voids in the resulting MMMs. Concurrently, C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs. As a result, the CO2 permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer, while the CO2/N2 and CO2/CH4 selectivity reached 21.5 and 14.4, respectively, substantially surpassing the 2008 Robeson upper bound. Additionally, molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO2 affinity of C@ZnO. In summary, we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.

Advances in the synthesis and applications of porous carbon materials.

Advances in the synthesis and applications of porous carbon materials.

Recent Advances in Porous Carbon Materials as Electrodes for Supercapacitors.

Porous carbon materials have demonstrated exceptional performance in various energy and environment-related applications. Recently, research on supercapacitors has been steadily increasing, and porous carbon materials have emerged as the most significant electrode material for supercapacitors. Nonetheless, the high cost and potential for environmental pollution associated with the preparation process of porous carbon materials remain significant issues. This paper presents an overview of common methods for preparing porous carbon materials, including the carbon-activation method, hard-templating method, soft-templating method, sacrificial-templating method, and self-templating method. Additionally, we also review several emerging methods for the preparation of porous carbon materials, such as copolymer pyrolysis, carbohydrate self-activation, and laser scribing. We then categorise porous carbons based on their pore sizes and the presence or absence of heteroatom doping. Finally, we provide an overview of recent applications of porous carbon materials as electrodes for supercapacitors.

Preparation of multistage microporous and mesoporous nitrogen-doped carbon nanospheres and study on electrocatalytic oxygen reduction

Non-metallic carbon-based catalysts are one of the most promising catalysts for electrocatalytic oxygen reduction (ORR). However, the controlled synthesis of the pore structures of carbon-based catalysts and the determination of catalytic sites still remains to be further explored. Based on this, two nitrogen-doped carbon-based catalysts with microporous and mesoporous structures were prepared in this paper. The two catalysts had different pore structures and nitrogen-doped species. The experimental results showed that the carbon-based catalyst (PC-NH3) rich in microporous structure and pyridine nitrogen doping had better catalytic performance, the electrocatalytic oxygen reduction performance of the catalyst was comparable to that of the platinum catalyst, and it had excellent methanol resistance and stability. This study provided important guidance for the application of porous carbon materials in oxygen reduction.

Ultrafastly activated needle coke as electrode material for supercapacitors

The uniform porous structure makes activated porous carbons (APCs) superior electrode material. Traditionally, APCs are produced by a combination of time-consuming high-temperature heat treatment and activation, with a production time of up to several hours. The produced APCs have relatively low specific surface area (SSA) and porosity. Therefore, the electrochemical performance is poor, which limits its application in high-power energy storage devices. Here, APCs materials are directly synthesized by a high temperature shock (HTS) strategy using needle coke as a precursor. The structure of as-prepared APC is characterized by XRD, SEM and Raman, and electrochemical tests confirmed its good electrochemical performance. In the two-electrode system, the supercapacitor with HTS-APC as the electrode material provides a high energy density of 35 ​Wh kg−1 and a high power density of 875 ​W ​kg−1 in EMIMBF4 ionic liquid. This work is instructive for the rapid synthesis of electrode materials, and also provides guidance for the large-scale application of porous carbon materials.

Preparation and electrochemical application of porous carbon materials derived from extraction residue of Ganoderma lucidum

As a valuable biomass resource, a large number of Chinese medicine residue have not been effectively utilized and are often treated as garbage, which not only causes environmental pollution, but also leads to the waste of resources. Ganoderma lucidum is a common raw material of Chinese herbal medicine, its natural mycelium and tube structure is conducive to the formation the porous structure of carbon materials. In this paper, porous carbon materials with high specific surface area and high pore volume were prepared by high temperature carbonization in nitrogen atmosphere using Ganoderma lucidum residue as a raw material and KOH as an alkali activator. The morphology and pore structure of the prepared carbon materials were analyzed and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction, Raman spectroscopy and nitrogen adsorption method. When the mass ratio of carbon to alkali was 1:4 and the temperature was 800 °C, ultra-high specific surface area microporous carbon materials were obtained with specific surface area of 3425 m3 g−1 and total pore volume of 1.74 cm3 g−1. The prepared porous carbon material was assembled into hydrogen peroxide electrode and cholesteric oxide modified electrode, which showed good catalytic performance.

A novel method to synthesize high-strength elastic gel and carbonized aerogel

Carbon aerogels have expanded the trend of the catalytic, adsorption, super capacitor field, and so on. Unfortunately, the real-world applications of porous carbon materials are limited because of the high cost, complicated preparation process and poor mechanical properties. Herein, we report an extremely simple and novel method to prepare carbon aerogels. Based on the principles of two-step curing including acid curing and heat curing, we develop a elastic Phenol-formaldehyde resin gel (PFRG) with high strength (18.9 MPa) from Phenol-formaldehyde resin (PFR) by controlling the loss of solvent in the process. Due to the robust network of RFRG, the Phenol-formaldehyde resin carbon aerogels (PFRCAs) can be directly procured through a tube furnace. The obtained PFRCAs possess macroporous/microporous hierarchical structure with high mechanical strength of 11.2 MPa and low thermal conductivity (0.0381 Wm/K). These results show that the proposed method can be promoted as a universal and promising method for preparing aerogel with thermosetting resin, which has driven a wider industrial utilization of aerogel and thermosetting resin.

Fast formation kinetics of methane hydrates loaded by silver nanoparticle coated activated carbon (Ag-NP@AC)

• Silver nanoparticle coated activated carbon (Ag-NP@AC) was synthesized. • Ag nanoparticles greatly enhance external nucleation kinetics out of porespace. • Ag-NP@AC leads to more enhanced hydrate kinetics than original activated carbon. • Ag-NP@AC saves 96.88% of induction time under low overpressure of 2.1 MPa. • Ag-NP@AC saves 85.25% of induction time under large water content of 1.4. Although activated carbon (AC) can significantly enhance hydrate nucleation kinetics due to abundant specific surface area and pore texture, the promotion drastically degenerates under low driving force and large water contents. Taking exceptional heat transfer of silver into account, silver nanoparticles were immobilized on activated carbon by in situ reduction method, giving rise to silver nanoparticle coated activated carbon (Ag-NP@AC), and the performance of Ag-NP@AC on hydrate formation kinetics was evaluated. Hydrate nucleation loaded by activated carbon was governed by external nucleation and that in inner pores, so slow hydrate nucleation was observed under low driving force and large water contents, where inner nucleation is hindered, and 500.67 min is required to induce hydrate nucleation at low overpressure (Δ P = 2.1 MPa), while 1145.4 min is inevitable for large water content ( R w = 1.4). Encouragingly, the presence of Ag nanoparticles significantly improves this limitation by enhancing external nucleation, Ag-NP@AC shortens hydrate induction time to a large extent, which reduces by 96.88% and 85.25% under mild condition (Δ P = 2.1 MPa) and large water content ( R w = 1.4), respectively. These findings provide new perspective on the application of porous carbon materials on hydrate-based solidified natural gas technologies.

Spherical Macroporous Carbon Nanotube Particles with Ultrahigh Sulfur Loading for Lithium-Sulfur Battery Cathodes.

A carbon host capable of effective and uniform sulfur loading is the key for lithium-sulfur batteries (LSBs). Despite the application of porous carbon materials of various morphologies, the carbon hosts capable of uniformly impregnating highly active sulfur is still challenging. To address this issue, we demonstrate a hierarchical pore-structured CNT particle host containing spherical macropores of several hundred nanometers. The macropore CNT particles (M-CNTPs) are prepared by drying the aerosol droplets in which CNTs and polymer particles are dispersed. The spherical macropore greatly improves the penetration of sulfur into the carbon host in the melt diffusion of sulfur. In addition, the formation of macropores greatly develops the volume of the micropore between CNT strands. As a result, we uniformly impregnate 70 wt % sulfur without sulfur residue. The S-M-CNTP cathode shows a highly reversible capacity of 1343 mA h g-1 at a current density of 0.2 C even at a high sulfur content of 70 wt %. Upon a 10-fold current density increase, a high capacity retention of 74% is observed. These cathodes have a higher sulfur content than those of conventional CNT hosts but nevertheless exhibit excellent performance. Our CNTPs and pore control technology will advance the commercialization of CNT hosts for LSBs.

Applications of porous carbon materials in the electrocatalysis of the oxygen reduction reaction

Oxygen reduction reactions (ORRs) are fundamental in various energy storage and conversion devices. Their activity determines the overall performance of these devices. Due to the sluggish kinetics of ORRs, a catalyst is often required, and in this regard, carbon materials are important as supports of noble metals such as Pt and Pd, and various non-noble metals, or even as metal-free catalysts. As a result, the development of porous carbons is playing a very important role in the advancement of ORR catalysts. We review the development of the ORR catalysts based on porous carbons, including their use as noble-/non-noble metal supports and metal-free catalysts, together with their synthesis methods and structural tuning. We also reviewtheir future prospects for ORR catalysis.