Three-dimensional Porous Carbon Research Articles

Direct synthesis of oxygen-enriched 3D porous carbons via NaCl template derived from oxidized coal tar pitch for excellent cycling stability electric double layer capacitor

A novel type of oxygen-enriched three-dimensional porous carbons (3DPCs) is prepared using coal tar pitch (CTP) oxidized by KMnO 4 as raw material and NaCl as a green template. Oxygen-containing functional groups are grafted on the edge of polycyclic aromatic hydrocarbons (PAHs) through oxidative modification, which avoids excessive accumulation of PAHs and successfully achieves oxygen doping to provide additional pseudo-capacitance. The existence of NaCl supports the formation of 3D structure and improves the diffusion/transport capacity of electrolyte ions. The as-prepared 3DPCs show interconnected 3D structure with large effective specific surface area (3067 m 2 g −1 ) and high oxygen content (up to 9.8%). In addition, the electric double layer capacitor assembled by 3DPC-3 exhibits the largest specific capacitance (306 F g −1 at 0.5 A g −1 ) and superior cycling stability (specific capacitance retention of 99.7% after 10000 cycles) in 6 M KOH electrolyte. Meanwhile, high energy density (36.8 Wh kg −1 ) is obtained when it is applied to EMIMBF 4 electrolyte. Overall, this work provides an effective way for the synthesis of 3DPCs and can be also conducive to the development of the high value-added CTP-based carbon material industry. • Coal tar pitch was oxidized by KMnO 4 . • Oxygen-enriched three-dimensional porous carbons was prepared. • Outstanding cycling performance up to 99.7% after 10000 cycles. • High energy density (36.8 Wh kg −1 ) in EMIMBF 4 electrolyte.

Gelatinization assisted synthesis of multi-heteroatoms enriched 3D honeycomb-like porous carbon for high-voltage supercapacitor device

Developing high-performance supercapacitors with low-cost electrode materials that possess high power energy while maintaining high specific energy is highly desirable and remains a major challenge. Herein, we report an N, S, P-multi-heteroatom co-doped three-dimensional (3D) honeycomb-like porous carbon nanosheets from garden cress seeds via facile two-step synthesis strategy involving gelatinization accompanied by KOH activation. The large specific surface area (1302.3 m2 g−1) and hierarchical porous structure has advantages of a well-balanced 3D interconnected micro-/meso‑/ and macropores for shorter ion pathway and provide rapid electrolyte penetration. When the as-obtained doped porous carbon is used as a supercapacitor electrode, it delivered high specific capacitance of 409 F g−1 and 279 F g−1 in aqueous three and two-electrode configuration, respectively. In addition, the device shows high cyclic stability of 93% even after 10,000 cycles. More importantly, the assembled symmetric supercapacitor device using 1 M tetraethylammonium tetrafluoroborate (TEABF4) as organic electrolyte (2.8 V) delivered outstanding specific energy of 31 Wh kg−1 (6.2 Wh L−1) at a specific power of 1300 W kg−1 (260 W L−1) and retained 25 Wh kg−1 even at a high specific power of 3000 W kg−1. Notably, the high voltage fabricated supercapacitor was able to power up various light-emitting diodes of voltage range from 1.8 to 3.8 V demonstrating its potential towards powering electronic devices. The strategy to employ cost-effective renewable garden cress seeds as biomass precursors to achieve hierarchical porous multi-heteroatom doped 3D carbon is of great interest for high-performance energy storage applications.

Double signal ratiometric electrochemical riboflavin sensor based on macroporous carbon/electroactive thionine-contained covalent organic framework

Riboflavin (RF) is one of the necessary vitamins. If human body lacks RF, it will lead to inflammation and dysfunction of mouth, lips and skin. Thus sensitive and accurate determination of RF is necessary. Here, an electroactive covalent-organic framework nanobelt (COFTFPB-Thi) with thickness of 1.4 nm was prepared by amine-aldehyde condensation reaction between thionine and 1, 3, 5-tris (p-formylphenyl) benzene, which was then grown vertically on three-dimensional porous carbon derived from kenaf stem (3D-KSC) for double signal ratiometric electrochemical detection of RF. The resulted 3D-KSC/COFTFPB-Thi showed two reduction peaks at −0.08 V and −0.23 V, which came from the reduction of COFTFPB-Thi and the conjugated structure of COFTFPB-Thi, respectively. In the presence of RF, those RF molecules near the electrode surface were oxidized at 0.6 V. Then some oxidized RF (RFox) adsorbed on COFTFPB-Thi would oxidize COFTFPB-Thi into COFTFPB-Thi(ox) while other RFox adsorbed on 3D-KSC kept unchanged. When the potential was scanned from 0.6 V to −0.6 V, both COFTFPB-Thi(ox) and RFox adsorbed on 3D-KSC were reduced at −0.08 V and −0.45 V accordingly, while the reduction peak of −0.23 V of the conjugated structure of COFTFPB-Thi kept constant. When j-0.45/j-0.23 was used as the response signal, the detection limit was 44 nM and the linear range was 0.13 μM −0.23 mM. By using j-0.08/j-0.23 as the response signal, a detection limit of 90 nM and a linear range of 0.30 μM-0.23 mM (S/N = 3) were obtained. By using double signals, the measurement results can be corrected to make the results more accurate and reliable. The sensor also showed good selectivity, reproducibility and stability, which provided a good application prospects.

Balsa wood derived three-dimensional hierarchical porous carbon materials as an anode material for K-ion batteries

Balsa wood derived three-dimensional hierarchical porous carbon materials as an anode material for K-ion batteries

Amorphous SnO2 nanoparticles embedded into a three-dimensional porous carbon matrix as high-performance anodes for lithium-ion batteries

Amorphous SnO2 nanoparticles embedded into a three-dimensional porous carbon matrix labeled as Am-SnO2@P-C are precisely customized through a phase separation process of tin salts and polyacrylonitrile/polyvinylpyrrolidone/N, N-dimethylformamide polymer mixed solution with the presence of deionized water and combining with heat treatments. The targeted composite powders are characterized by X-ray diffraction, X-ray photoelectron spectroscope, transmission electron microscope, and scanning electron microscope, in which amorphous SnO2 nanoparticles with ultrafine diameters are uniformly distributed across the three-dimensional porous carbon matrix. The Am-SnO2@P-C composite electrode can deliver an initial discharge and charge specific capacity of 1557.6 and 1194.4 mAh/g with an initial coulombic efficiency of 76.7 % at 100 mA/g, and the discharge specific capacity can be retained at 886.4 mAh/g after 200 cycles. Moreover, the Am-SnO2@P-C composite electrode also exhibits great rate capability, in which the electrode can deliver a reversible capacity of 581.1 mAh/g at the current density as high as 1.0 A/g with a capacity retention of 92.8 % after 500 cycles. Furthermore, the kinetics investigations of pseudocapacitive contributions and electrochemical impedance spectroscopy on the as-prepared composite electrodes demonstrate the fast electrochemical kinetics of the Am-SnO2@P-C electrode due to the synergistic effect of the ultrafine size of amorphous SnO2 nanoparticles and the porous carbon matrix. Those findings and understandings of the SnO2 based electrodes may offer some a prospective strategy of the metal-oxide based anodes for lithium-ion batteries in the field of energy storages.

Ultralight Coral-like hierarchical Fe/CNTs/Porous carbon composite derived from biomass with tunable microwave absorption performance

In order to widen the application field of microwave absorption (MA) materials, it is still challenging to obtain high-performance MA materials with wide frequency bandwidth, lightweight, thin thickness, and strong absorption by an economical and sustainable method. Herein, the novel coral-like hierarchical structure with zero-dimensional Fe nanocrystals, one-dimensional N-doped carbon nanotubes (CNTs) and three-dimensional porous carbon (PC) matrix is rationally constructed to enhance MA performance. Based on renewable biomass residues, the composite consisted of PC as matrix, bamboo-shaped CNTs with magnetic nanoparticles at the top grow on the surface of PC. By controlling the growth conditions of carbon nanotube, the microstructure and dielectric loss capacity of composite can be manipulated to optimize the impedance matching, reflection loss (RL), and effective absorption bandwidth (EAB, the bandwidth of RL < -10 dB). Benefitting from the unique architecture and hierarchical composite, the composite exhibited a minimum RL of −70 dB at thin thickness of 1.9 mm under low filler content of 12.5 wt%. Even with the thickness of 1.5 mm, the RL could reach −51.8 dB with a broadcast EBA of 5.0 GHz. This work provides an insight for designing advanced microwave absorbers with lightweight, thin thickness, strong RL, and wide EAB.

Efficient Removal of Chromium(VI) Using a Novel Waste Biomass Chestnut Shell-Based Carbon Electrode by Electrosorption.

Biomass-derived porous carbon materials have a good application prospect in electrosorption because of their low cost, abundant natural resources, and excellent performance. In this work, three-dimensional interconnected structure porous carbon (CPC) was successfully synthesized from waste biomass chestnut shells by carbonization and chemical activation processes. The unique structure of CPC could offer superior double-layer capacitance and excellent conductivity. The as-obtained CPC was applied as an electrosorption electrode. In the deionization experiments, the removal efficiency of the CPC electrode in a 30 mg L–1 chromium(VI) aqueous solution at 1.0 V was 90.5%. The electrosorption follows pseudo-second-order kinetics. The CPC electrode also presented good regeneration performance in the regeneration test. These results demonstrate that the as-prepared carbonaceous material is an ideal material for capacitive deionization electrodes.

In-situ vulcanization synthesis of honeycomb-like SnS/C nanocomposites as anode materials for lithium-ion batteries

SnS has become a popular anode material for lithium-ion batteries (LIBs) because of its higher theoretical capacity and lower cost. However, the huge volume change and dissolution of sulfur lead to sharply attenuated capacity and less than ideal rate performance in the process of repeated discharge/charge. Here we use silica spheres and allyl thiourea as hard template and carbon/sulfur sources, respectively, to synthetize SnS nanoparticles anchored three-dimensional porous carbon (SnS/C nanocomposites) by in-situ carbonization and vulcanization method. As a result, the SnS/C nanocomposites exhibit high specific capacity (607.6 mA h g−1 at 0.1 A g−1), excellent rate performance (313.2 mA h g−1 at 3 A g−1), and outstanding cycling stability (404.7 mA h g−1 after 300 cycles at 1 A g−1). The distinguished electrochemical performance of SnS/C nanocomposites is due to the N, S-doped three-dimensional porous carbon interconnection structure and the wide range of SnS nanoparticles in the carbon matrix. Such combination not only improves the conductivity of the material but also maintains the integrity of the structure, eventually improving the cycling stability of the material.

Confinement of Zn-Mg-Al-layered double hydroxide and α-Fe2O3 nanorods on hollow porous carbon nanofibers: A free-standing electrode for solid-state symmetric supercapacitors

Nano confinement of Layered double hydroxide (LDHs) nanosheets and metal oxide is a compelling way to develop new functional materials with unique physiochemical features for various energy storage devices with enhanced performance. Herein, ternary zinc-magnesium-aluminum layered double hydroxide (ZMA-LDH) nanosheets and hematite (α-Fe2O3) nanorods are confined in a hetero-interfacial orientation on electrospun three-dimensional hollow and porous carbon nanofibers (3DHPCNF) by a subsequent hydrothermal process, resulting in the formation of a multi-dimensional nanoarchitecture. Such a structure can incorporate a conductive matrix and eliminate the need of current collectors, thereby minimizing the dead mass in electrochemical energy storage materials. The amount of Zn significantly determines the structural, morphological, and electrochemical properties of ZMA-LDH nanostructures. ZMA-LDH@Fe2O3/3DHPCNF was used as a free-standing electrode material for supercapacitors and endowed high capacitive behavior at both positive and negative working potentials. With the well-arranged 1D-3D hollow and porous interconnection, increased terrestrial surface area, and superior electrical conductivity, the hierarchical composite electrode offers a high areal capacitance of 3437F cm−2 at 1 mA cm−2 and ultrahigh cyclic stability. This fascinating electrochemical performance is attributed to the synergistic effect of 1D/2D/3D hollow and porous nanostructures, bimetallic compositions, top-to-bottom utilization of electrode materials, and unique combinations of surface interfacial diffusion and faradaic reduction governed by carbon and LDH/Fe2O3, respectively. Furthermore, a flexible all solid-state ZMA-LDH@Fe2O3/3DHPCNF symmetric supercapacitor exhibited a high areal energy density at a high power density along with excellent cyclability. This result suggests new prospects to design highly efficient multi material based electrodes for energy storage devices.

Cobalt-decorated 3D hybrid nanozyme: A catalytic amplification platform with intrinsic oxidase-like activity

Research about constructing multi-dimensional carbon nanomaterials is of great significance in electrocatalytic and sensing fields in order to integrate structural merits of each individual unit. Also, nanomaterials with enzyme-like activities are prospective candidates for artificial enzyme design and electrochemical application. Herein, we fabricate Co, N co-doped hierarchical hybrid (Co@NCNTs/NC) nanozyme, which integrates of both N-doped carbon nanotubes (NCNTs) and N-doped carbon sheets (NC). The three-dimensional (3D) porous carbon composite is prepared by thermal treatment of metal-organic framework (MOF) which was synthesized by growing of ZIF-67 on ZIF-L at room temperature. The obtained nanomaterial not only possesses an improved oxidase-like activity that can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) in the absence of hydrogen peroxide (H2O2), but also constructs a signal amplification platform towards dopamine (DA) due to the synergistic catalysis of Co species and N-doped porous carbon architecture. The electrocatalytic performance for DA detection shows a broad linear range from 30 nM to 710 μM and a detection limit of 9 nM. The Co@NCNTs/NC/GCE is employed to practically detect DA in human serum and artificial cerebrospinal fluid (aCSF) samples with satisfactory results. The present work exhibits a great promising in colorimetric and electrochemical sensing fields and presents a new sight for the fabrication of MOF-derived nanozyme.

A novel iron-based composite flocculant for enhanced wastewater treatment and upcycling hazardous sludge into trifunctional electrocatalyst

Sewage sludge, an unavoidable by-product of industrial wastewater treatment, is facing multitudinous challenges in drawing a cost-effective compromise between environmental and economic acceptance. The aim of this research is to produce high-quality energy materials by utilizing hazardous waster as precursors. A novel inorganic-organic composite flocculant was first manufactured and used as an efficient binary-coagulant for enhanced dyes removal and Fe-containing textile sludge (TS-Fe) production from dyeing wastewater. Then, three-dimensional interconnected hierarchical porous iron-nitrogen doped carbon materials (TS-Fe-N-C) were fabricated by pyrolysis of TS-Fe to realize the resource recovery. Upon accurate control the composition of TS-Fe-N-C, the optimal TS-Fe-N-C-0.23 has excellent performance for oxygen reduction reaction (half-wave potential of 0.837 V), oxygen evolution reaction (overpotential of 0.328 V at 10 mA cm-2), and hydrogen evolution reaction (overpotential of 0.144 V at 10 mA cm-2). Moreover, Zn-air battery and water splitting device based on TS-Fe-N-C-0.23 electrodes displayed satisfactory energy density (770.0 mAh g-1), power density (120.5 mW cm-2), and low water splitting voltage (1.70 V @ 10 mA cm-2). This study suggests that rational design of flocs by conventional wastewater treatment technologies is an effective strategy for optimizing the composition of sludge and boosting the additional value to the sludge-derived biochar product.

Three-dimensional hierarchical porous carbon derived from natural resources for highly efficient treatment of polluted water

BackgroundDealing with the ever-increasing water pollution has become an urgent global problem, especially the organic containing polluted water. Physical adsorption has become one of the most popular ways for removal of organic dyes from wastewater due to its low cost as well as high efficiency. However, the adsorption performance is still limited by the low specific surface area (SSA) and unsuitable pore size. Hence, it is still a challenge to synthesize active carbon (AC) with high SSA, suitable pore size distribution as well as low cost for polluted water treatment. Here, we report an efficient method to prepare AC with large SSA from jujube for removal of both cationic dye and anionic dye from aqueous solution. The present results demonstrate that biomass-derived hierarchical porous carbon has a real potential application for wastewater treatment.ResultsThe as-prepared hierarchical porous structure carbon material (PC-500-6) shows a high specific surface area (3203 m2/g) and pore size distribution in the range 0.8 to 3.0 nm, while exhibiting an enhanced adsorption performance for both methylene blue (MB) and methylene orange (MO) from an aqueous solution. The maximum adsorption capacity even reaches 925.93 mg/g and 1281.39 mg/g for MB and MO, which was calculated from Langmuir model. Through analysis of the adsorption data, it was found that the corresponding adsorption kinetic fits the pseudo-second-order model very well.ConclusionsIt can be concluded that the adsorption of MB has a strong correlation with SSA, pore size distribution as well as the pore volume. The present study paved a practical way for wastewater treatment by using biomass-derived hierarchical porous carbon.

Metal-Organic Framework Derived Ultrafine Sb@Porous Carbon Octahedron via In Situ Substitution for High-Performance Sodium-Ion Batteries.

Alloying-type anode materials are regarded as promising alternatives beyond intercalation-type carbonaceous materials for sodium storage owing to the high specific capacities. The rapid capacity decay arising from the huge volume change during Na+-ion insertion/extraction, however, impedes the practical application. Herein, we report an ultrafine antimony embedded in a porous carbon nanocomposite (Sb@PC) synthesized via facile in situ substitution of the Cu nanoparticles in a metal-organic framework (MOF)-derived octahedron carbon framework for sodium storage. The Sb@PC composite displays an appropriate redox potential (0.5-0.8 V vs Na/Na+) and excellent specific capacities of 634.6, 474.5, and 451.9 mAh g-1 at 0.1, 0.2, and 0.5 A g-1 after 200, 500, and 250 cycles, respectively. Such superior sodium storage performance is primarily ascribed to the MOF-derived three-dimensional porous carbon framework and ultrafine Sb nanoparticles, which not only provides a penetrating network for rapid transfer of charge carriers but also alleviates the agglomeration and volume expansion of Sb during cycling. Ex situ X-ray diffraction and in situ Raman analysis clearly reveal a five-stage reaction mechanism during sodiation and desodiation and demonstrate the excellent reversibility of Sb@PC for sodium storage. Furthermore, post-mortem analysis reveals that the robust structural integrity of Sb@PC can withstand continuous Na+-ion insertion/extraction. This work may provide insight into the effective design of high-capacity alloying-type anode materials for advanced secondary batteries.

In-situ growth of molecularly imprinted metal–organic frameworks on 3D carbon foam as an efficient adsorbent for selective removal of antibiotics

In recent years, Metal-organic frameworks (MOFs) have attracted extensive attention in the field of adsorption owing to their advantages such as large specific surface area and rich active sites, but the adsorption performance of MOFs is not ideal for the removal of macromolecular organics. In this study, a novel composite material for the efficient and selective removal of norfloxacin (NOR) from wastewater has been successfully prepared via combining molecular imprinting (MI) technology and in-situ growth strategy, in which evenly dispersed MOFs particles are perfectly anchored to three-dimensional porous carbon foam (CF). Owing to more active sites exposed by three-dimensional imprinted holes and the excellent transport properties of CF, the as-prepared MI-MOF/CF exhibits a maximum capacity of 456 mg/g for NOR, which is far superior to that of the pristine MOF. Moreover, the adsorption rate is significantly increased, and the adsorption equilibrium could be reached within 60 min. Interestingly, the selective pharmaceuticals adsorption performance of MI-MOF/CF depends not only on the pore size, but also on the specific recognition ability of the active sites where modified with carboxyl compounds. This work effectively solves the bottleneck encountered by MOFs in the removal of large size antibiotic molecules, and provides a new direction for the design and synthesis of MOFs in the future.

Uniform Deposition and Effective Confinement of Lithium in Three-Dimensional Interconnected Microchannels for Stable Lithium Metal Anodes.

Lithium dendrite formation has hindered the practical implementation of lithium metal batteries with higher energy densities compared with those of conventional lithium-ion batteries. Herein, a nanoconfinement strategy to access dendrite-free lithium metal anodes comprising three-dimensional (3D) hollow porous multi-nanochannel carbon fiber embedded with TiO2 nanocrystals (HTCNF) is reported. The transport of the lithium ions is facilitated by the 3D architecture. Functioning as nanoseeds, the TiO2 nanocrystals guide the lithium ions toward forming uniform deposits, which are further confined inside the hollow carbon fibers and the 3D HTCNF layer. Site-selective deposition coupled with the nanoconfinement of lithium metal modifies the Li plating/stripping behavior and effectively suppresses the dendrite growth. The HTCNF-Li cell delivers a stable cycling performance of 1300 h with a voltage hysteresis as low as 6 mV. The assembled HTCNF-Li//LiFePO4 full cell displays a compelling rate performance and enhanced cycling stability with high capacity retention (90% after 400 cycles at 0.5 C). Our results demonstrate a new and potentially scalable route to resolve the lithium dendrite growth issue for enhanced electrochemical performances, which can be further extended to other metal battery systems.

Simultaneous determination of paracetamol and Dopamine, and detection of bisphenol a using Three-dimensional interconnected porous carbon functionalized with ionic liquid

Three-dimensional interconnected porous carbon (3DIPC) materials were successfully prepared by a simple one-step pyrolysis reaction from sodium citrate. Then, the 3DIPC was combined with 1-vinyl-3-ethylimidazolium tertrafluoroborate [(VEIM)BF 4 ] and ultrasonicated to form 3DIPC-ionic liquid (3DIPC-IL). The 3DIPC-IL modified glassy carbon electrode (3DIPC-IL/CS/GCE) displayed good electrocatalytic activity toward paracetamol (PA), dopamine (DA), and bisphenol A (BPA). • Three-dimensional interconnected porous carbon (3DIPC) materials were successfully prepared firstly and then combined with 1-vinyl-3-ethylimidazolium tertrafluoroborate [(VEIM)BF 4 ] to form 3DIPC-ionic-liquid (3DIPC-IL). • The fabricated 3DIPC-IL chitosan coated glassy carbon modified electrode (3DIPC-IL/CS/GCE) displayed good electrocatalytic activity toward paracetamol (PA), dopamine (DA), and bisphenol A (BPA). • The modified electrode possesses good selectivity to PA and DA, and can be used to simultaneous determination of PA and DA. • The electrochemical sensor exhibits high sensitivity, good stability, and good selectivity for the determination of PA and DA, BPA. In this work, three-dimensional interconnected porous carbon (3DIPC) materials were successfully prepared by a simple one-step pyrolysis reaction from sodium citrate. Then, the 3DIPC was combined with 1-vinyl-3-ethylimidazolium tertrafluoroborate [(VEIM)BF 4 ] and ultrasonicated to form 3DIPC-ionic liquid (3DIPC-IL). Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to determine the structure and morphology of the 3DIPC and 3DIPC-IL. The fabricated 3DIPC-IL chitosan coated glassy carbon modified electrode (3DIPC-IL/CS/GCE) displayed good electrocatalytic activity toward paracetamol (PA), dopamine (DA), and bisphenol A (BPA). Using this technique, PA and DA can be detected simultaneously and BPA can be detected as well. Under ideal conditions, the sensor displays two linear ranges of 1.0 to 200 μM and 200 to 700 μM for PA and of 1.0 to 100 μM and 100 to 500 μM for DA. In addition, a linear range of 2.0 to 100.0 μM was established for BPA. The detection limits of PA, DA, and BPA were determined to be 0.58 μM, 0.13 μM, and 0.028 μM (S/N = 3), respectively. The 3DIPC-IL/CS/GCE also exhibits high sensitivity, good stability, and good selectivity for the determination of PA, DA, and BPA.

Facile fabrication of three-dimensional porous carbon embedded with SnO2 nanoparticles as a high-performance anode for lithium-ion battery

Facile fabrication of three-dimensional porous carbon embedded with SnO2 nanoparticles as a high-performance anode for lithium-ion battery

FeCo/FeCoP encapsulated in N, Mn-codoped three-dimensional fluffy porous carbon nanostructures as highly efficient bifunctional electrocatalyst with multi-components synergistic catalysis for ultra-stable rechargeable Zn-air batteries

Currently, it is critical but a tricky point to develop economical, high-efficiency, and durable non-precious metal electrocatalysts towards oxygen reduction and oxygen evolution reaction (ORR/OER) in rechargeable Zn-air batteries. Herein, N, Mn-codoped three-dimensional (3D) fluffy porous carbon nanostructures encapsulating FeCo/FeCoP alloyed nanoparticles (FeCo/FeCoP@NMn-CNS) are prepared by one-step pyrolysis of the metal precursors and polyinosinic acid. The optimized hybrid nanocomposite (obtained at 800 °C, named as FeCo/FeCoP@NMn-CNS-800) exhibits outstanding catalytic performance in the alkaline electrolyte with a half-wave potential (E1/2) of 0.84 V for the ORR and an overpotential of 325 mV towards the OER at 10 mA cm−2. Impressively, the FeCo/FeCoP@NMn-CNS-800-assembled rechargeable Zn-air battery presents an open-circuit voltage of 1.522 V (vs. RHE), a peak power density of 135.0 mW cm−2, and long-term durability by charge-discharge cycling for 200 h, surpassing commercial Pt/C + RuO2 based counterpart. This work affords valuable guidelines for exploring advanced bifunctional ORR and OER catalysts in rational construction of high-quality Zn-air batteries.

Three-dimensional porous N-doped graphitic carbon framework with embedded CoO for photocatalytic CO2 reduction

A facile polymer thermal treatment method has been employed to fabricate 3D porous N-doped graphitic carbon frameworks with embedded CoO (CoO@N-GCs), which are employed as catalysts for the photocatalytic reduction of CO2. The experimental results demonstrate that the CoO@N-GC-500 catalyst exhibits excellent photocatalytic performance and stability for the photoreduction of CO2 in water. Under visible light irradiation, the maximum yields for CH4 and CO are 10.03 μmol/(h·g) and CO is 5.16 μmol/(h·g), respectively. The high photocatalytic performance of CoO@N-GC-500 is attributed to the efficient separation of the photogenerated electron-hole pairs, large specific surface area, and strong visible light absorption capacity. This work paves a new way for the practical application of the CoO catalysts in artificial photosynthesis.

Three-dimensional hierarchical porous carbon derived from resorcinol formaldehyde-zinc tatrate/poly(styrene-maleic anhydride) for high performance supercapacitor electrode

Herein, we propose a three-dimensional hierarchical porous carbon (THPC) derived from interpenetrating polymer networks (IPNs) of resorcinol formaldehyde-zinc tartrate and poly(styrene-maleic anhydride) (RF-Zn/PSMA), which was prepared via a gel swelling method. The three-dimensional hierarchical and interconnected pore structure involving micro-, meso- and macropores benefits from the synergistic pore-forming effect of PSMA pyrolysis and zinc tartrate decomposition during carbonization process. A high specific surface area of 742 m2 g−1 together with a cheese-like morphology was found for obtained THPC, exhibiting a high specific capacitance of 235 F g−1 at 1 A g−1 in 6 M KOH. THPC assembled symmetrical supercapacitor using 6 M KOH and 1 M Na2SO4 as electrolytes deliver energy outputs of 6.47 and 15.3 Wh kg−1 at 100 and 180 W kg−1, respectively. More attractively, the assembled supercapacitor based on the THPC achieves a high energy outputs of 50.45 Wh kg−1 at 350 W kg−1 in EMIMBF4 under wide potential window of 3.5 V, indicating its practical application prospect. Our findings open up new playgrounds for the design and electrochemical application of hierarchical porous carbon using IPNs as precursor.