Efficient selective adsorption of Cr(VI) by S-doped porous carbon prepared from industrial lignin: Waste increment and wastewater treatment.

Industrial lignin is a waste product of the paper industry, which contains a large amount of oxygen group structure, and can be used to treat industrial wastewater containing Cr(VI). However, lignin has very low reactivity, so how to enhance its adsorption performance is a major challenge at present. In this study, a two-stage hydrothermal and activation strategy was used to activate the lignin activity and doping S element to prepare high-performance S-doped lignin-based polyporous carbon (S-LPC). The results show that the surface of S-LPC is rich in S and O groups and has a well-developed pore structure, which is very beneficial to Cr(VI) uptake -reduction and mass transfer on the material. In the wastewater, the utmost adsorption potential of Cr(VI) by S-LPC achieved 882.83 mg/g. After 7 cycles of regeneration, the adsorption of S-LPC decreased by only approximately 18 %. Ion competition experiments showed that S-LPC has excellent specificity for Cr(VI) adsorption. In factory wastewater, the adsorption performance of S-LPC for Cr(VI) remained above 95 %, which shows the excellent performance of S-LPC in practical applications. The results are of great significance for green chemical utilization of waste lignin, treatment of industrial wastewater and sustainable development.

Rational design of amorphous vanadium pentoxide and hollow porous carbon spheres hybrid for superior zinc-ion battery.

Aqueous zinc-ion batteries (AZIBs) are expected to be a promising large-scale energy storage system owing to their intrinsic safety and low cost. Nevertheless, the development of AZIBs is still plagued by the design and fabrication of advanced cathode materials. Herein, the amorphous vanadium pentoxide and hollow porous carbon spheres (AVO-HPCS) hybrid is elaborately designed as AZIBs cathode material by integrating vacuum drying and annealing strategy. Amorphous vanadium pentoxide provides abundant active sites and isotropic ion diffusion channels. Meanwhile, the hollow porous carbon sphere not only provides a stable conductive network, but also enhances the stability during charging/discharging process. Consequently, the AVO-HPCS exhibits a capacity of 474 mAh/g at 0.5 A/g and long-term cycle stability. Moreover, the corresponding reversible insertion/extraction mechanism is elucidated by ex-situ X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. Furthermore, the flexible pouch battery with AVO-HPCS cathode shows high comprehensive performance. Hence, this work provides insights into the development of advanced amorphous cathode materials for AZIBs.

Hierarchical Bi2O3 nanosheets and ZIF-8 derived porous nitrogen-doped carbon fibers as novel assembled nanocomposites for high-performance flexible supercapacitors.

The unique design of the core-shell heterostructure is significant for obtaining electrode materials with excellent electrochemical properties. In this paper, porous carbon nanofibers (NPC@PPZ) embedded with N-doped porous carbon nanoparticles are used to construct flexible electrodes (NPC@PPZ@Bi2O3). Zeolite imidazole skeleton (ZIF)-8 and poly(methyl methacrylate) (PMMA) derived porous carbon fibers and Bi2O3 nanosheets, were utilized as the porous core and multilayer shell, respectively. The unique core and shell result in abundant pores and channels for fast ion transport and storage, high specific surface area, and additional electroactive sites. This perfect structural design enables the NPC@PPZ@Bi2O3 composite electrode to have excellent electrochemical performance. The results show that this electrode can obtain a high specific capacitance of 697 F g-1 at a current density of 1 A g-1 and a stable cycling performance at a high current density of 5 A g-1. The strategy developed in this study provides a new approach for the design and fabrication of flexible supercapacitors by electrostatic spinning combined with hierarchical porous structures.

Dielectric barrier discharge low-temperature plasma modification of bamboo charcoal for supercapacitor applications.

Biochar is commonly utilized as an electrode material in supercapacitors. However, the conventional carbonization process often results in macromolecular compounds, which obstruct the porous structure of carbon materials, thereby reducing their capacitance. Dielectric barrier discharge low-temperature plasma (DLTP) is a technology that transforms gases into highly excited states, utilizing high-energy particles for enhanced energy applications. This study investigated the effects of DLTP on the electrochemical performance of bamboo charcoal (BC), utilizing bamboo shavings (BS) as the carbon source. The results indicated that the specific capacitance of BC varied under different atmospheric conditions, input voltages, and treatment durations, thereby achieving a maximum increase of 144 F/g. Furthermore, when combined with KOH activation, DLTP modification further enhanced the specific capacitance of BC to 237 F/g. The DLTP treatment enhanced the specific surface area and the types of functional groups in BC, thereby leading to a significant enhancement of its electrochemical properties.

Nucleic acid-functionalized nanoscale porous carbon-based electrochemical genosensor for detection of Nocardia spp. in real samples.

In this study, a porous carbon derived from a metal-organic framework (PCMOF) as a target-responsive material functionalized with Nocardia particular antisense ssDNA oligonucleotide (ssDNA capture probe) was developed to construct a simple genosensor based on biogatekeeper strategy for sensitive detection of Nocardia in complex biological samples. The PCMOF with suitable pores volume was used to encapsulate electroactive dye methylene blue (MB), and the ssDNA capture probe was used as a gatekeeper to cap PCMOF. Without the presence of Nocardia target, the electrochemical signal of trapped MB was high. Upon adding the target, the hybridization of ssDNA capture probe and target led to the formation of a probe-target double-stranded (dsDNA) structure which dissociated from PCMOF and allowed MB molecules to be released. Therefore, the electrochemical signal of the genosensor decreased. The detection of Nocardia was accomplished by observing variations in the MB peak current intensity in a dose-dependent manner. For this genosensor, a linearity range from 10-18 to 10-7 M for synthetic ssDNA target and 10 to 108 copies/mL for two standard isolates, Nocardia farcinica PTCC 1309 and Nocardia brasiliensis ATCC 19296 as well as for clinical isolates (identified as Nocardia otitidiscaviarum) was observed, respectively. The detection limit (DL) values were 0.54 aM for synthetic ssDNA target and 5, 7, and 4 copies/mL for N. farcinica, N. brasiliensis, and N. otitidiscaviarum, respectively. This genosensor was also characterized by good specificity, reproducibility, and stability.

Anthracite-derived porous carbon@MoS2 heterostructure for elevated lithium storage regulated by the middle TiO2 layer.

The rational design of MoS2/carbon composites have been widely used to improve the lithium storage capability. However, their deep applications remain a big challenge due to the slow electrochemical reaction kinetics of MoS2 and weak bonding between MoS2 and carbon substrates. In this work, anthracite-derived porous carbon (APC) is sequential coated by TiO2 nanoparticles and MoS2 nanosheets via a chemical activation and two-step hydrothermal method, forming the unique APC@TiO2@MoS2 ternary composite. The dynamic analysis, in-situ electrochemical impedance spectroscopy as well as theoretical calculation together demonstrate that this innovative design effectively improves the ion/electron transport behavior and alleviates the large volume expansion during cycles. Furthermore, the introduction of middle TiO2 layer in the composite significantly strengthens the mechanical stability of the entire electrode. As expected, the as-prepared APC@TiO2@MoS2 anode displays a high lithium storage capacity with a reversible capacity of 655.8 mAh g-1 after 150 cycles at 200 mA g-1, and robust cycle stability. Impressively, even at a high current density of 2 A g-1, the electrode maintains a superior reversible capacity of 597.7 mAh g-1 after 1100 cycles. This design highlights a feasibility for the development of low-cost anthracite-derived porous carbon-based electrodes.

Preparation of functionalized porous chitin carbon to enhance the H2O2 production and Fe3+ reduction properties of Electro-Fenton cathodes for efficient degradation of RhB.

The performance of Electro-Fenton (EF) cathode materials is primarily assessed by H2O2 yield and Fe3+ reduction efficiency. This study explores the impact of pore structure in chitin-based porous carbon on EF cathode effectiveness. We fabricated mesoporous carbon (CPC-700-2) and microporous carbon (ZPC-700-3) using template and activation methods, retaining nitrogen from the precursors. CPC-700-2, with mesopores (3-5 nm), enhanced O2 diffusion and oxygen reduction, producing up to 778 mg/L of H2O2 in 90 min. ZPC-700-3, with a specific surface area of 1059.83 m2/g, facilitated electron transport and ion diffusion, achieving a Fe2+/Fe3+ conversion rate of 79.9%. EF systems employing CPC-700-2 or ZPC-700-3 as the cathode exhibited superior degradation performance, achieving 99% degradation of Rhodamine B, efficient degradation, and noticeable decolorization. This study provides a reference for the preparation of functionalized carbon cathode materials for efficient H2O2 production and effective Fe3+ reduction in EF systems.

Polypyrrole deposited on the core-shell structured nitrogen-doped porous carbon@Ag-MOF for signal amplification detection of chloride ions.

An electrochemical platform for signal amplification probing chloride ions (Cl-) is constructed by the composite integrating core-shell structured nitrogen-doped porous carbon@Ag-based metal-organic frameworks (NC@Ag-MOF) with polypyrrole (PPy). It is based on the signal of solid-state AgCl derived from Ag-MOF, since both NC and PPy have good electrical conductivity and promote the electron transport capacity of solid-state AgCl. NC@Ag-MOF was firstly synthesized with NC as the scaffold and then, PPy was anchored on NC@Ag-MOF by chemical polymerization. The composite NC@Ag-MOF-PPy was utilized to modify the electrode, which exhibited a higher peak current and lower peak potential during Ag oxidation compared with those of Ag-MOF and NC@Ag-MOF-modified electrodes. More importantly, in the coexistence of chloride (Cl-) ions in solution, the NC@Ag-MOF-PPy-modified electrode displayed a fairly stable and sharp peak of solid-state AgCl with the peak potentials gradually approaching zero, which might effectively overcome the background interference caused by electroactive substances. The oxidation peak currents of solid-state AgCl increased linearly with the concentration of  Cl- ions in a broad range of 0.15 µM-40 mM and 40-250 mM, with detection limits of 0.10 µM and 40 mM, respectively. The practical applicability for Cl- ions determination was demonstrated using human serum and urine samples. The results suggest that NC@Ag-MOF-PPy composite could be a promising candidate for the construction of the electrochemical sensor.

Unraveling the Capacitive Behaviors in Nanoconfined Ionophilic Carbon Pores.

Intensifying the synergy between confined carbon nanopores and ionic liquids (ILs) and a deep comprehension of the ion behavior is required for enhancing the capacitive storage performance. Despite many theoretical insights on the storage mechanism, experimental verification has remained lacking due to the intricate nature of pore texture. Here, a compressed micropore-rich carbon framework (CMCF) with tailored monolayer and bilayer confinement pores is synthesized, which exhibits a compatible ionophilic interface to accommodate the IL [EMIM][BF4]. By deploying in situ Raman spectroscopy, in situ Fourier-transform infrared spectroscopy, and solid-state nuclear magnetic resonance, the effect of the pore textures on ions storage behaviors is elucidated. A voltage-induced ion gradient filling process in these ionophilic pores is proposed, in which ion exchange and co-ion desorption dominate the charge storage process. Moreover, it is established that the monolayer confinement of ions enhances the capacity, and bilayer confinement facilitates the charging dynamics. This work may guide the design of nanoconfinement carbon for high-energy-density supercapacitors and deepen the understanding of the charge storage mechanism in ionophilic pores.

Sustainability-inspired upcycling of plastic waste into porous carbon nanobulks for water decontamination via peroxymonosulfate activation.

"White pollution" is regarded as one of the most serious problems in the natural environment. Thus greener recycling of plastic waste has attracted significant efforts in recent research. In this study, to kill two birds with one stone, a series of porous carbon nanobulks (PCNs) were synthesized from the pyrolysis of plastic waste (polyethylene terephthalate, PET) and inorganic salt (including NaHCO3, Na2CO3, NaCl, and ZnCl2) for sulfadiazine (SDZ) degradation via peroxymonosulfate (PMS) activation. PCNs-1 (co-calcinated from PET and NaHCO3) with a large number of CO and COOH active sites, which were in favor of PMS activation and electron transfer during the catalytic process, had shown the best catalytic activity for SDZ degradation. Significantly, PCNs-1 exhibited excellent universality, adaptability, and stability. The degradation pathways of SDZ were identified by the total content of organic carbon (TOC), and high-resolution mass spectrometry (HR-MS). The possible mechanism was proposed according to the anion effect, quenching experiments, electron paramagnetic resonance (EPR), and electrochemical analysis, indicating that radical (OH, SO4-, O2-) and non-radical (1O2 and e) species were the catalytically active species for SDZ decomposition in the PCNs-1/PMS system. Moreover, Ecological Structure-Activity-Relationship Model (ECOSAR) program and wheat seed cultivation experiments clearly demonstrated that the biotoxicity of SDZ could be effectively reduced by the PCNs-1/PMS system. Here we successfully upcycled plastic waste into high-value materials for efficient water decontamination.

Homologous Temperature Regulated Hierarchical Nanoporous Structures by Dealloying.

Nanoporous metals, fabricated via dealloying, offer versatile applications but are typically limited to unimodal porous structures, which hinders the integration of conflicting pore-size-dependent properties. A strategy is presented that exploits the homologous temperature (TH)-dependent scaling of feature sizes to generate hierarchical porous structures through multistep dealloying at varied TH levels, adjusted by altering dealloying temperatures or the material melting points. This technique facilitates the creation of monolithic architectures of bimodal porous nickel and trimodal porous carbon, each characterized by well-defined, self-similar bicontinuous porosities across distinct length scales. These materials merge extensive surface area with efficient mass transport, showing improved current delivery and rate capabilities as electrodes in electrocatalytic hydrogen production and electrochemical supercapacitors. These results highlight TH as a unifying parameter for precisely tailoring feature sizes of dealloyed nanoporous materials, opening avenues for developing materials with hierarchical structures that enable novel functionalities.

Enhanced electrocatalytic activity in MOFs-derived 3D hollow NiCo-LDH nanocages decorated porous biochar for simultaneously ultra-sensitive electrochemical sensing of Cu2+ and Hg2.

Layered double hydroxides (LDHs) have attracted significant attention due to their compositional and structural flexibility. However, it is challenging but meaningful to design and fabricate hierarchical mixed-dimensional LDHs with synergistic effects to increase the electrical conductivity of LDHs and promote the intrinsic activity. Herein, 3D hollow NiCo-LDH nanocages decorated porous biochar (3D NiCo-LDH/PBC) has been synthesized by using ZIF-67 as precursor, which was utilized for constructing electrochemical sensing platform to realize simultaneous determination of Cu2+ and Hg2+. The 3D NiCo-LDH/PBC possessed the characteristics of hollow material and three-dimensional porous material, revealing a larger surface area, more exposed active sites, and faster electron transfer, which is beneficial to enhancing its electrochemical performance. Consequently, the developed sensor displayed good performance for simultaneously detecting Cu2+ and Hg2+ with ultra-low limit of detection (LOD) of 0.03 µg L-1 and 0.03 µg L-1, respectively. The proposed sensor also demonstrated excellent stability, repeatability and reproducibility. Furthermore, the sensor can be successfully used for the electrochemical analysis of Cu2+ and Hg2+ in lake water sample with satisfactory recovery, which is of great feasibility for practical application.

A Highly Selective Acetone Sensor Based on Coal-Based Carbon/MoO2 Nanohybrid Material.

High temperature represents a critical constraint in the development of gas sensors. Therefore, investigating gas sensors operating at room temperature holds significant practical importance. In this study, coal-based porous carbon (C-700) and coal-based C/MoO2 nanohybrid materials were synthesized using a simple one-step vapor deposition and sintering method, and their gas-sensing performance was investigated. The gas-sensing performance for several VOC gases (phenol, ethyl acetate, ethanol, acetone, triethylamine, and toluene) and a 95% RH high-humidity environment were tested. The results indicated that the C/MoO2-450 sample sintered at 450 °C exhibited excellent specific selectivity towards acetone at room temperature, with a response value of 4153.09% and response/recovery times of 10.8 s and 2.9 s, respectively. Furthermore, the C/MoO2-450 sample also demonstrated good repeatability and long-term stability. The sensing mechanism of the synthesized materials was also explored. The superior gas-sensing performance can be attributed to the synergistic effect between the porous carbon and MoO2 nanoparticles. Given the importance of enhancing the high-tech and high-value-added utilization of coal, this study provides a viable approach for utilizing coal-based carbon materials in detecting volatile organic compounds at room temperature.

Hierarchical Magnetic Carbon Nanoflowers for Ultra-Efficient Electromagnetic Wave Absorption.

Porous carbon nanomaterials are widely applied in the electromagnetic wave absorption (EMWA) field. Among them, an emerging flower-like carbon nanomaterial, termed carbon nanoflowers (CNFs), has attracted tremendous research attention due to their unique hierarchical flower-like structure. However, the design of flower-like carbon nanomaterials with different magnetic cores for EMWA has rarely been reported. Herein, a general template method is proposed to achieve a set of high-quality magnetic CNFs, namely Co@Void@CNFs, CoNi@CNFs, and Ni@CNFs. The prepared magnetic CNFs have highly accessible surface area and internal space, rich heteroatom content, multi-scale pore system, and uniform and highly dispersed magnetic nanoparticles, as a result, deliver superior EMWA performance. Specifically, when the thickness is 2.6 mm, the Co@Void@CNFs exhibit a maximum refection loss (RLmax) of -56.6 dB and an effective absorption bandwidth (EAB) from 8.0 to 12.1 GHz covering the whole X band. The CoNi@CNFs have an RLmax of up to -57.6 dB and a wide EAB of 5.6 GHz at just 1.9 mm. For the Ni@CNFs, possess an ultra-broad EAB of 6.1 GHz, covering the entire Ku band at 2.0 mm. Overall, the hierarchical magnetic carbon nanoflowers proposed here offer new insights toward realizing multifunctional integrated carbon nanomaterials for EMWA.

Flexible phase change film based on lignin-derived porous carbon/Eicosane for wearable thermal management and microwave absorption.

A flexible phase-change film with thermal management and microwave absorption capabilities was developed for use in wearable devices. The film was created using a solution casting method based on a porous carbon-loaded eicosane (LP33/EI) material. LP33 served as the porous encapsulation medium, while Eicosane (EI) acted as the phase change component. The flexible substrate was a blend of polyvinyl alcohol (PVA) and bacterial cellulose nanocellulose (BC). The ultrathin film had a thickness of 0.262 mm, and LP33/EI-4 exhibited exceptional mechanical strength of 188 MPa. Testing revealed that the phase transition process had melting and crystallization enthalpies of 134.71 J/g and 126.11 J/g, respectively. The encapsulation structure effectively prevented any leakage during the phase transition process. Under simulated solar irradiation of 200 mW/cm2, LP33/EI-4 achieved a photothermal conversion efficiency (η) of 89.46 %. Additionally, the porous LP33 structure and high dielectric loss contributed to remarkable microwave absorption capabilities of -42 dB in the X-band and - 52 dB in the Ku-band. Overall, LP33/EI films demonstrated exceptional performance in thermal management, energy storage, and microwave absorption, making them an ideal choice for a variety of applications in wearable devices.

N-doped porous carbon with ZIF-67-derived CoFe2O4-Fe particles for supercapacitors.

The development of novel materials for electrodes with high energy densities is essential to the advancement of energy storage technologies. In this study, N-doped layered porous carbon with ZIF-67-derived binary CoFe2O4-Fe particles was successfully fabricated by the pyrolysis of an Fe-based chitosan (CS) hydrogel mixed with ZIF-67 particles. Various characterization techniques were employed to assess the performance of the prepared porous CoFe2O4-Fe@NC composite. This composite exhibits excellent performance owing to the effective combination of multivalent CoFe2O4-Fe particles derived from ZIF-67 with N-doped porous carbon substances with a high surface area, which helps to accelerate ion and charge transfer. The specific capacitance of the CoFe2O4-Fe@NC composite carbonized at 700 °C reached 3960.9F/g at 1 A/g. When this composite is combined with activated carbon (AC) to construct an asymmetric supercapacitor (ASC), a density of energy of up to 84.9 W h kg-1 is attained at a power capacity of 291.6 W kg-1. Moreover, this composite maintained a capacitance retention of up to 94.9 % after 10,000 cycles. This work offers new perspectives on high-performance supercapacitors and their applications.

Cobalt-copper bimetallic selenides embedded in nitrogen-doped porous carbon nanocubes for diclofenac electrochemical sensing.

Diclofenac (DCF) is a non-steroidal anti-inflammatory drug (NSAID), and its overuse poses a potential threat to human health and the aquatic environment, designing high-efficiency electrocatalysts for DCF detection is urgent. Herein, cobalt-copper bimetallic selenides embedded in nitrogen-doped porous carbon nanocubes (CoCuSe@NC) were elaborately designed via one-step in situ selenization of bimetallic CoCu-MOF. The chemical constituents and micromorphology of CoCuSe@NC composites can be further optimized by precisely regulating the selenization process and the doping ratio of bimetal in MOF precursor. As an electrocatalyst, CoCuSe@NC was proved to be highly efficient in electrochemical sensing of DCF with a broad linear range of 0.1-400 µmol/L and a detection limit of 0.024 µmol/L. This was attributed to the synergistic advantages between the heterogeneous structures, which produced more electrochemically active sites, effectively shortened the electron transport path, and improved electrocatalytic performance. Consequently, the constructed sensor exhibits high sensitivity, remarkable stability and applicability, and in particular can selectively detect DCF from other structurally similar coexisting analogs, resulting from the unique metal chelation ability. This work paves the way for designing effective bimetallic selenide electrocatalysts and exploring their applications in DCF electrochemical sensing.

Photocatalytic degradation of antibiotics by N-doped carbon nanoflakes-nickel ferrite composite derived from algal biomass.

This work reports the synthesis of nickel ferrite (NiFe) nanoparticles, N-doped mesoporous carbon nanoflakes (NCF) and novel nickel ferrite-carbon nanoflakes (NiFe@NCF) nanocomposite using solvothermal method. NCF was derived from a cyanobacterial consortium consisting of Anabaena, Lyngbya and Weistiellopsis, rich in carbon and nitrogen. The synthesized nanoparticles were used as heterogeneous photocatalyst for degradation of two harmful water pollutants, ciprofloxacin (CIP) and levofloxacin (LEV). 99.91% LEV and 98.86% CIP were degraded within 50 and 70 min of visible light irradiation using NiFe@NCF following pseudo first order kinetics. This improved efficiency of the nanocomposite may be attributed to its higher surface area, reduction of band gap (from 2.42 to 2.19 eV), more active sites as well as charge carrier mobility with decreasing agglomeration tendency of the magnetic nickel nanoparticles upon being embedded on NCF. N-doping improves light harvesting property, retards charge recombination and extends as well as delocalises á´¨-conjugated system resulting in enhanced photocatalytic activity. The scavenging experiments and EPR analysis reveal that O2-• and •OH are the main active species taking part in the degradation process. The material performs well within a wide range of pH and can be effectively used up to 5 repetitive cycles. A feasible photocatalytic degradation mechanism of the antibiotics against NiFe@NCF nanocomposite is also put forwarded along with their possible degradation pathways from LCMS studies.

Biomass-Derived Materials for Advanced Rechargeable Batteries.

Biomass-derived materials generally exhibit uniform and highly-stable hierarchical porous structures that can hardly be achieved by conventional chemical synthesis and artificial design. When used as electrodes for rechargeable batteries, these structural and compositional advantages often endow the batteries with superior electrochemical performances. This review systematically introduces the innate merits of biomass-derived materials and their applications as the electrode for advanced rechargeable batteries, including lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, and metal-sulfur batteries. In addition, biomass-derived materials as catalyst supports for metal-air batteries, fuel cells, and redox-flow batteries are also included. The major challenges for specific batteries and the strategies for utilizing biomass-derived materials are detailly introduced. Finally, the future development of biomass-derived materials for advanced rechargeable batteries is prospected. This review aims to promote the development of biomass-derived materials in the field of energy storage and provides effective suggestions for building advanced rechargeable batteries.

High-Entropy Metal Nitride Embedded in Concave Porous Carbon Enabling Polysulfide Conversion in Lithium-Sulfur Batteries.

The practical implementation of lithium-sulfur batteries is severely hindered by the rapid capacity fading due to the solubility of the intermediate lithium polysulfides (LiPSs) and the sluggish redox kinetics. Herein, high-entropy metal nitride nanocrystals (HEMN) embedded within nitrogen-doped concave porous carbon (N-CPC) polyhedra are rationally designed as a sulfur host via a facile zeolitic imidazolate framework (ZIF)-driven adsorption-nitridation process toward this challenge. The configuration of high-entropy with incorporated metal manganese (Mn) and chromium (Cr) will optimize the d-band center of active sites with more electrons occupied in antibonding orbitals, thus promoting the adsorption and catalytic conversion of LiPSs. While the concave porous carbon not only accommodates the volume change upon the cycling processes but also physically confines and exposes active sites for accelerated sulfur redox reactions. As a result, the resultant HEMN/N-CPC composites-based sulfur cathode can deliver a high specific capacity of 1274 mAh g-1 at 0.2 C and a low capacity decay rate of 0.044% after 1000 cycles at 1 C. Moreover, upon sulfur loading of 5.0 mg cm-2, the areal capacity of 5.0 mAh cm-2 can still be achieved. The present work may provide a new avenue for the design of high-performance cathodes in Li-S batteries.