3D Porous Framework Research Articles

Constructing Mechanical Shuttles in a Three‐dimensional (3D) Porous Architecture for Selective Transport of Lithium Ions

AbstractLithium (Li) extraction from brines is a major barrier to the sustainable development of batteries and alloys; however, current separation technology suffers from a trade‐off between ion selectivity and permeability. Herein, a crown ether mechanically interlocked 3D porous organic framework (Crown‐POF) was prepared as the porous filler of thin‐film nanocomposite membranes. Crown‐POF with penta‐coordinated (four Ocrown atoms and one Ntert‐amine atom) adsorption sites enables a special recognition for Li+ ion. Moreover, the four Ntert‐amine atoms on each POF branch facilitate the flipping motion of Li+ ion along the skeletal thread, while retaining the specified binding pattern. Accordingly, the crown ether interlocked POF network displays an ultrafast ion transfer rate, over 10 times that of the conventional porous materials. Notably, the nanocomposite membrane gives high speed and selectivity for Li+ ion transport as compared with other porous solid‐based mixed‐matrix membranes.

Facile two-step synthesis of nickel nanoparticles supported on 3D porous carbon frameworks as an effective electrocatalyst for urea and methanol oxidation

The design and development of facile and environmentally-friendly methods to prepare low-cost, high-activity electrocatalysts are desirable for the development of fuel cells. In our study, a high-efficiency anodic electrocatalyst for the oxidation of urea and methanol based on nickel nanoparticles supported on three-dimensional porous carbon frameworks (Ni/3DPCFs) was designed by an innovative and simple method. This innovative method is based on the preparation of carbon quantum dots (CQDs) and nickel ions (Ni2+) adsorbed on its surface by microwave-assisted synthesis, followed by pyrolysis. The method is notable for simultaneously preparing Ni2+ and CQDs and not requiring a stabilizer, surfactant, or organic solvent. The results of scanning and transmission electron microscopy (SEM and TEM) revealed that the CQDs were converted to 3DPCFs by pyrolysis and nickel nanoparticles (NiNPs) were formed on the surface. The prepared electrocatalyst showed high efficiency for the oxidation of urea and methanol in alkaline media. The electrocatalytic activity of Ni/3DPCFs showed the maximum anodic current density of 102.5 and 153.8 mA/cm2 for urea and methanol oxidation, respectively. This method can provide a simple and novel approach to producing various metallic nanoparticles supported on 3DPCFs as electrocatalysts by two-step microwave-assisted synthesis and pyrolysis without using toxic reagents and surfactants.

Two Acentric Aluminoborates Incorporated d10 Cations: Syntheses, Structures, and Nonlinear Optical Properties.

Two acentric aluminoborates (ABOs), [Zn(en)2Al{B5O9(OH)}{BO(OH)2}] (1) and [Cd(en)2AlB5O10]·H2O (2) (en = ethylenediamine), have been solvothermally made. 1 includes a two-dimensional (2D) wavy ABO layer using B5O9(OH) clusters and AlO3{BO(OH)2} groups, in which both units can be regarded as three-connected nodes, and simplifying the ABO layer to a hcb-type network. 2 features an acentric three-dimensional (3D) porous framework with a unique unc-type network constituted by strictly alternating connected B5O10 clusters and AlO4 units. The structural transformation from a 2D layer 1 to a 3D framework 2 was achieved with the elimination of the terminal hydroxyls in layer 1 by adjusting synthetic conditions in the same solvent system. Metal-amine complexes Zn(en)2/Cd(en)2 bond to the inorganic walls and are located in the cavity of frameworks 1 and 2, respectively. Compounds 1 and 2 exhibit large second-harmonic generation (SHG) responses that are 2.2 and 2.7 times those of KH2PO4 (KDP), respectively, which are among the largest powder SHG responses for all deep-ultraviolet (deep-UV) ABOs. The UV-vis diffuse reflectance spectra of 1 and 2 show a wide transparency window below 190 nm. Density functional theory (DFT) calculations indicate that the B-O units and the introduced distorted d10 metal polyhedra played a decisive role in the optical properties of both compounds.

A Ti3C2Tx@PANI core-shell heterostructure assembled into a 3D porous hydrogel as a free-standing electrode for high-energy supercapacitors.

Although Ti3C2Tx MXenes have attracted attention in electrochemical energy storage devices due to their excellent electronic conductivity, controllable layer structure, and huge redox active surface area, the application of Ti3C2Tx as supercapacitor (SC) electrode materials is severely limited by the ineffective chemical ion transport kinetics caused by self-restacking. In order to increase the interlayer spacing of Ti3C2Tx, the intercalation method is hailed as an effective process. Herein, polyaniline (PANI) nanorods as intercalators were synthesized by the polymerization of an aniline (ANI) monomer chemisorbed onto Ti3C2Tx wrinkled nanosheets, and the formation of a Ti3C2Tx@PANI heterostructure is conducive to the large interlayer voids. Then, the heterostructure was integrated into a three-dimensional (3D) porous cross-linked framework via a simple graphene oxide (GO)-assisted self-convergence hydrothermal strategy with low temperatures. Due to the synergistic effect among each component and 3D porous interconnected structure, the hierarchical Ti3C2Tx@PANI-reduced graphene oxide (RGO) heterostructure hydrogel possesses the advantages of excellent electrical conductivity, high specific capacitance, repressive aggregation, and large electrochemical active area. Heterostructure hydrogel electrodes (without binders) display excellent electrochemical performance with a specific capacitance as high as 301.0 F g-1 at 1 A g-1, 90.74% capacitance retention over 10 000 cycles, and a maximum energy density of 44.6 W h kg-1 at a power density of 504.7 W kg-1. Our study provides a fresh strategy for constructing a 3D Ti3C2Tx-based framework applicable to other MXenes in the design of hybrid structures for maximizing their potential applications in energy storage.

Porous Zn-MOF with two diverse cages synthesized using functionalized biphenyl tricarboxylic acid: CO2 selective adsorption and fixation

A new MOF 1 shows a 3D porous framework formed by the interconnected dodecahedron and octahedron cages. Thus, the activated MOF 1 not only has excellent selective adsorption performance for C2H2, CO2 and CH4, but also has good catalytic performance for the reaction of CO2 fixation.

Reveals that electron transfer regime mediated by electron shuttle rather than adjacent transfer in B-doped 3D porous carbon framework: Exploration of interactions and identification of the main active site

The determination of non-radical pathways and identification of the main active site in the persulfate (PS) activation by B-doped carbonaceous materials are still controversial. Therefore, sodium citrate was selected as the carbon source and self-template for synthesizing a B-doped carbonaceous materials to activate peroxydisulfate (PDS) in this work. Multiple characterizations and experiments revealed that the electron transfer regime was responsible for the activation of PDS. On the one hand, the metastable surface complexes were generated due to the adsorption of PDS onto the catalyst surface via inner-sphere interaction. On the other hand, the interaction between BPA and the catalyst was verified as charge-assisted hydrogen bonding. In addition, BC3 was identified as the main active site. Based on the detailed and in-depth exploration of the electron transfer regime during the PDS activation of B-doped carbonaceous materials, this work further elucidated interactions, and the vital role of BC3 in PDS activation.

Lanthanide metal-organic frameworks containing ferromagnetically coupled metal-carboxylate chains showing slow magnetic relaxation behavior

Lanthanide metal-organic frameworks (Ln-MOFs) with slow magnetic relaxation behavior are of great interest to scientists due to their rich and peculiar physical phenomena and spin-related applications. In this contribution, the syntheses, characterizations and magnetic properties of two new Ln-MOFs: {[Ln2(btpdc)3·DMF·2H2O]·2DMF·4H2O}n (Ln = Dy (1), Gd (2), H2btpdc = benzo[b]thiophene-2,6-dicarboxylic acid) are reported. Single crystal X-ray diffraction experiments show the two complexes are isostructural with three dimensional (3D) porous framework structure constructed by metal-carboxylate chains separated by long organic linkers. Direct-current (dc) magnetic susceptibilities recorded under 1000 Oe reveal the overall exchange couplings in both the two MOFs are ferromagnetic. Interestingly, the ferromagnetic coupled metal-carboxylate chains in 1 are sufficiently isolated by the long organic linkers that makes 1 exhibit slow magnetic relaxation behavior and Ising-like behavior which was rarely reported for lanthanide-carboxylate complexes.

A “two-for-one” strategy to construct a LiFePO4@C cathode with 3D porous framework for high-energy Li-on batteries

LiFePO4 (LFP), as one of the most promising cathodes, still faces the challenge of low electrical conductivity. Carbon coating is one of the most effective strategies to promote electrical conductivity. However, the combination of LFP with common carbon usually has low surface area and porosity, which leads to low Li+ transfer. Herein, we proposed a “two for one” strategy to improve the electronic conductivity and Li+ transfer of LFP. The porous nanocomposites were obtained by using nanocellulose fibers (CNF) and metal organic frameworks (MOFs) as the double-carbon sources and structural regulators. Among them, CNF with abundant -OH can provide more sites for coordination with LFP and construct continuous pathways for electrons. Besides, MOFs serves as the porous framework to enlarge the electrode/electrolyte contact area, and provide fast transportation pathways for Li+. With the synergistic effect of the two carbons, the composites show mesoporous structure with high electronic conductivity and fast Li+ transportation rate. As cathode for Li-ion batteries, it exhibits high specific capacity of 168 mAh g−1 with energy density of 574 Wh kg−1. Besides, it exhibits excellent cycle stability with capacity retention of 91% after 1000 cycles. Above all, the construction method shows general applicability for other electrode materials.

Design of corn straw/paraffin wax shape-stabilized phase change materials with excellent thermal buffering performance

The introduction of 3D structured supporting materials is reckoned as an effective way to relieve the liquid leakage and improve the shape stabilization of phase change materials (PCMs). However, the complicated preparation process and high cost restrict their large-scale application. Herein, shape-stabilized composite PCMs are designed with cheap corn straw (CS) as 3D porous framework via simple pre-treatments. The loading efficiency of paraffin wax (PW) is up to 99.7%, resulting in superior thermal storage and release performance of CS/PW (CP) composite PCMs with phase change enthalpy above 185 J/g. The shape stability temperature of CP rises to 95 °C due to the capillary force. Excellent thermal buffering effect is proved by five highly consistent thermal cycles and only a little loss appears after 200 cycles. Moreover, CP mat with a diameter of 8 cm shows superior thermal buffering performance to retard the cooling of water and avoid the high temperature of table. As compared to rubber mat, 5.6 °C rise on water temperature and 14.5 °C reduction on table temperature are accomplished by CP mat, demonstrating the great application prospect in the field of thermal buffering materials and laying a foundation for the large-scale application of PCMs.

A 3D porous framework constructed from [(PIIIO3)2Mo5O15]6− clusters and {Cu(en)2} units: Synthesis, crystal structure and electrochemical properties

A new organic-inorganic hybrid, formulated as the H2[Cu(en)2]2[(PIIIO3)2Mo5O15]·4H2O (denoted as CuenP2Mo5) (en=ethylenediamine), was isolated via in situ self-assembly reaction of H3PO3, (NH4)6Mo7O24.4H2O, en, and CuCl2·2H2O in the aqueous solution. Structural analysis reveals that CuenP2Mo5 display a three-dimensional (3D) porous framework assembled from the [(PIIIO3)2Mo5O15]6− clusters linked with the {Cu(en)2} units. The morphology of CuenP2Mo5 feature a lamellar construction, smooth surface and regular edges with sizes 50–100 µm. Electrochemical studies reveal that CuenP2Mo5 exhibits the multi-electron redox processes ascribed to MoVI and CuII centers, and has good electrocatalytic activity in the reduction of H2O2. CuenP2Mo5 modified electrode shows a wide linear range (50–450 µM), high sensitivity of 1.76 µA·µM−1 and a low detection limit of 0.45 µM for the electrochemical detection of H2O2.

Carrier-free Chinese herbal small molecules self-assembly with 3D-porous crystal framework as a synergistic anti-AD agent

Alzheimer's disease (AD) is a devastating neurodegenerative disease caused by multiple factors. Single-target drugs have limited efficacy for AD treatment. Therefore, multi-target intervention strategy has great potential. Traditional Chinese medicine (TCM) is mostly used in the form of compound prescription, which has the polypharmacology behavior. Rhizoma Coptidis and Radix et Rhizoma Rhei are frequently used as the couplet medicines of TCM for AD therapy. In this study, the novel carrier-free nanoassembly with 3D-porous frame crystal structure has formulated from supramolecular self-assembly of berberine (BER) and rhein (RHE), the main active components of Rhizoma Coptidis and Radix et Rhizoma Rhei, respectively. Combining with the spectral data and single crystal structure, the self-assembly process was clarified as dominated by electrostatic interaction and π-π stacking. In vitro release property, cholinesterase (ChE) inhibition, β-amyloid (Aβ) aggregation regulation, radical elimination, metal ions chelation and cytotoxicity assay indicated that the obtained BER-RHE assembly had the Fickian diffusion-controlled sustained release ability, synergistic biological activities and virtually no neurotoxicity. In addition, in vivo reactive oxygen species (ROS) level evaluation showed that the assembly could reduce the accumulation of intracellular ROS in Caenorhabditis elegans (C. elegans). Meanwhile, BER-RHE assembly could also be used as a novel potential carrier for drug delivery due to its superior 3D-porous frame. This green and facile strategy for carrier-free nanoassembly microscopic construction via supramolecular self-assembly might provide inspiration for the development of multi-target therapy for AD and the design of the novel drug delivery system.

Synthesis and Structure of a Copper-Based Functional Network for Efficient Organic Dye Adsorption.

In the work, by incorporating polyoxometalates (POMs) into a copper(II)-based network, a novel three-dimensional (3D) porous framework, [Cu17Cl3(trz)12]H3[GaW12O40]·9H2O (Cu-GaW-TRZ), was successfully prepared and explored for the adsorption of dyes. The adsorption capacity of Cu-GaW-TRZ was calculated as 13.11 mg/g, and the dye adsorption rate equaled 96.2% for the adsorption of methylene blue (MB). Furthermore, this recyclable adsorbent is stable enough without obvious loss of adsorption capacity for at least five runs. Meanwhile, the structure of the macropores is suitable for the entry of large molecular dyes, and [GaW12O40]5- also can achieve efficient adsorption for cationic dyes. The results displayed a pseudo-second-order kinetic model and were well matched for MB adsorption onto Cu-GaW-TRZ. The free energy, entropy, and enthalpy of the thermodynamic parameters for the adsorption of MB were calculated, which revealed that the adsorption process was befitting for the adsorption of MB.

Novel Ag-bridged dual Z-scheme g-C3N4/BiOI/AgI plasmonic heterojunction: Exceptional photocatalytic activity towards tetracycline and the mechanism insight

Rational design and synthesis of highly efficient and robust photocatalysts with positive exciton splitting and interfacial charge transfer for environmental applications is critical. Herein, aiming at overcoming the common shortcomings of traditional photocatalysts such as weak photoresponsivity, rapid combination of photo-generated carriers and unstable structure, a novel Ag-bridged dual Z-scheme g-C3N4/BiOI/AgI plasmonic heterojunction was successfully synthesized using a facile method. Results showed that Ag-AgI nanoparticles and three-dimensional (3D) BiOI microspheres were decorated highly uniformly on the 3D porous g-C3N4 nanosheet, resulting in a higher specific surface area and abundant active sites. The optimized 3D porous dual Z-scheme g-C3N4/BiOI/Ag-AgI manifested exceptional photocatalytic degradation efficiency of tetracycline (TC) in water with approximately 91.8% degradation efficiency within 165 min, outperforming majority of the reported g-C3N4-based photocatalysts. Moreover, g-C3N4/BiOI/Ag-AgI exhibited good stability in terms of activity and structure. In-depth radical scavenging and electron paramagnetic resonance (EPR) analyses confirmed the relative contributions of various scavengers. Mechanism analysis indicated that the improved photocatalytic performance and stability were ascribed to the highly ordered 3D porous framework, fast electron transfer of dual Z-scheme heterojunction, desirable photocatalytic performance of BiOI/AgI and synergistic effect of Ag plasmas. Therefore, the 3D porous Z-scheme g-C3N4/BiOI/Ag-AgI heterojunction had a good prospect for applications in water remediation. The current work provides new insight and useful guidance for designing novel structural photocatalysts for environment-related applications.

Fe3Se4 rice grains anchored on cotton-derived porous carbon network for enhanced sodium ion storage and hydrogen evolution reactions

Transition-metal selenides have been regarded as promising anode materials for energy storage and conversion fields. However, their practical application is hindered by volume expansion, polyselenide dissolution, and sluggish kinetics. Herein, porous Fe3Se4 rice grains were successfully encapsulated on cotton derived carbon network (CN@Fe3Se4@C) by facile solvothermal method combined with in-situ selenization process. Beneficial from the unique structure, the CN@Fe3Se4@C electrode exhibits excellent sodium storage properties (302 mAh g−1 at 500 mA g−1 after 500 cycles) and hydrogen evolution reactions (HER) performance (an overpotential of 168 mV at a current density of 10 mA cm−2, and a low Tafel slope of 77 mV dec−1). Electrochemical mechanism investigations demonstrate that the carbon coated porous Fe3Se4 nanoparticles and ant nest-like carbon network can shorten the diffusion path for Na+ ions and suppress volume expansion. Meanwhile, the 3D interconnected porous carbon framework can provide multiple channels for fast electron transport and improve electron conductivity. In addition, the thin amorphous carbon layers on individual Fe3Se4 rice grains can well inhibit the shuttle effect of polysulfides and the agglomeration of Fe3Se4, ensuring fast kinetics and long-term stability. This study reveals the great potential of CN@Fe3Se4@C as active materials for sodium ion batteries and hydrogen production.

Highly Porous Cyanometallic Spin-Crossover Frameworks Employing Pyridazino[4,5-d]pyridazine Bridge

Single crystals of two spin-crossover (SCO) cyanometallic coordination polymers based on the pyridazino[4,5-d]pyridazine ligand (pp) of the composition [Fe(pp)M(CN)4]∙G (where M = Pd, Pt; G = guest molecules) were obtained by a slow diffusion technique. A single-crystal X-ray analysis showed that both compounds adopted the structure of porous 3D frameworks, consisting of heterometallic cyano-bridged layers and interlayer pillar pp ligands, with a total solvent accessible volume of ca. 160 Å3 per iron(II) ion (about 37% of the unit cell volume). These frameworks displayed hysteretic SCO behaviour with T1/2 of 150/190 K (heating/cooling) for Pd complex and 135/170 K (heating/cooling) for Pt complex, which was confirmed by variable-temperature SCXRD experiments. This research shows the perspective of using pp ligand for building porous MOFs with spin transitions.

Constructing 3D Tent-Like frameworks in melamine hybrid foam for superior microwave absorption and thermal insulation

Taking serious electromagnetic pollution and practical application requirements into consideration, it’s imperative to develop multifunctional microwave absorption materials. In this work, the phenol–formaldehyde resin (PF) successfully adheres to melamine–formaldehyde foam (MF) as three-dimensional (3D) porous frameworks, and subsequently the substrate anchors few-layered MXene nanosheets by dripping-squeeze-drying procedures. According to the results, the hollow tent-like structure of MXene/PF@MF (MPM) shows a significant effect on microwave absorption capability, including extending heterogeneous interfaces for polarization relaxation and prolonging microwave propagation paths for energy dissipation. Based on the synergy of multiple components and rational structure, MPM exhibits a minimum reflection loss (RLmin) value of −58.8 dB at 2.2 mm and achieves an effective absorption bandwidth (EAB) of 6.74 GHz covering the entire Ku band. The microwave absorption mechanism reveals that the superior microwave absorption capability results from high conduction loss, polarization relaxation, multiple attenuations, and appropriate impedance matching. Furthermore, the MPMs possess lightweight features (32.7–48.7 g cm−3) and low thermal conductivity (0.0309–0.0318 W m−1 K−1) benefitting the unique 3D porous structure. Meanwhile, the low thermal conductivity endows MPMs with infrared stealth, which broadens the application in military fields. This work proposes a facile strategy for constructing highly efficient microwave absorbers with multiple functions.

Lightweight 3D interconnected porous carbon with robust cavity skeleton derived from petroleum pitch for effective multi-band electromagnetic wave absorption

Ingenious porous skeleton design is highly desired for advanced carbonaceous electromagnetic wave absorbers (EWAs) to address the issues of impedance mismatch and enhance attenuation ability. Herein, a controllable structure of petroleum pitch-derived coral-like 3D interconnected porous carbon (PC) framework is constructed in one step by a hard-template method. The well-designed air-filled 3D interconnected cavity structure provides ideal impedance matching for absorbers and facilitates the multiple scattering of electromagnetic waves, while continuous robust carbon skeleton exhibits a satisfied electrical conductivity (≈553 S/m), greatly boosting the electrical energy loss capability of PCs. Therefore, even under an ultralow filler loading of only 6 wt%, the corresponding minimum reflection loss (RL) values of multiple thicknesses are all below −20 dB in the range of 1.5–5.0 mm, and the strongest RL of PCs reaches −50.04 dB (matching thickness is 2.37 mm), the widest effective absorption bandwidth is up to 4.4 GHz. The overall performance outperforms most of previously reported carbon-based EWAs. This synthetic strategy presents a broad application prospect due to its simple preparation method and lost-cost raw materials, and provides a new route for the design of advanced lightweight absorbers from abundant inferior heavy oil. Lightweight 3D interconnected porous carbon material with robust cavities skeleton is prepared by a facile template method and yields excellent multi-band electromagnetic wave absorption at an ultralow filler loading. • 3D porous carbon framework with robust cavity skeleton is prepared by a facile salt template strategy. • 3D interconnected cavity structure endows porous carbon with strong conduction loss and excellent impedance matching. • Porous carbon yields a high electromagnetic wave absorption property (−50.04 dB) at an ultralow filler loading of 6 wt%. • Highly-efficient multi-band electromagnetic wave absorption has been achieved by simply tuning the thickness. • This work offers a new route for the design of advanced carbon-based absorbers from low-cost petroleum pitch.

N···I···N]+ Type Halogen-Bonding-Driven Supramolecular Helical Polymers with Modulated Chirality.

The [N···I···N]+ type halogen bond has been utilized to synthesize supramolecular architectures, while the applications in constructing helical motifs and modulating supramolecular chirality have been unexplored so far. In this work, the [N···I···N]+ halogen bond was introduced to drive the formation of supramolecular helical polymers via a Ag(I) coordination intermediate, showing tunable supramolecular chirality. Pyridine segments were conjugated to the asymmetric ferrocene skeleton, which show "open" and "closed" geometry depending on the sp2 N positions. Coordination with Ag(I) generated one-dimensional (1D) double helices and 2D helicates featured the [Ag(O)···I···Ag(O)]+ bond, which further stacked into 3D porous frameworks with chiral channels and adjustable pore sizes. Ionic exchange afforded 1D supramolecular helical polymers in solution phases driven by the [N···I···N]+ type halogen bonds, which was evidenced by the experimental results and density functional theory calculation. Fc2 exclusively demonstrated tunable supramolecular chirality in the formation of coordinated and halogen bonded polymers. In addition, solvent change would further inverse the helicity of halogen bonded supramolecular helical polymers depending on the rotation of the ferrocenyl core whose "closed" and "open" states were accompanied by the breakage of intramolecular hydrogen bonds. This work introduces a [N···I···N]+ type ionic halogen bond to prepare supramolecular helical polymers, providing multiple protocols in regulating helicity by ion exchange and solvent environments.

A Highly Selective MOF-Based Probe for Turn-On Luminescent Detection of Al3+, Cr3+, and Fe3+ in Solution and Test Paper Strips through Absorbance Caused Enhancement Mechanism.

Trivalent metal ions (Cr3+, Al3+, and Fe3+) constitute a major section of the environmental pollutants, and their excess accumulation has a detrimental effect on health, so their detection in trace quantity has been a hot topic of research. A highly scalable 3D porous Zn-based luminescent metal-organic framework (MOF) has been synthesized by exploiting the mixed ligand synthesis concept. The strategic selection of an aromatic π-conjugated organic linker and N-rich spacer containing the azine functionality as metal ion binding sites immobilized across the pore spaces, have made this MOF an ideal turn-on sensor for Al3+, Cr3+, and Fe3+ ions with very high sensitivity, selectivity, and recyclability. An in-depth study revealed absorbance caused enhancement mechanism (ACE) responsible for such turn-on phenomena. In order to make the detection process straightforward, convenient, portable, and economically viable, we have fabricated MOF test paper strips (the MOF could be simply immobilized onto the paper strips) for naked eye visual detection under UV light, which, thus, manifests its potential as a real-time smart sensor for these trivalent ions.

Construction of 3D Porous Carbon Frameworks for Supercapacitors: Abundant Pore Structure and Proper Hydrophilicity

A biomass-derived 3D porous carbon (3DPC) framework with multi-heteroatom (N, O, and S) doping was easily fabricated by an easy, efficient, and low-cost method. In the approach, the template action and pore activation were simplified into one step, which differed from previous methods of preparing porous carbon. By exfoliating the porous carbon into graphene-like laminar nanosheets using NaCl and expanding the pore structure with KOH during the ball milling process, followed by carbonization under a suitable temperature, the prepared porous carbon afforded good electric conductivity (6.3 S cm–1 under 7 MPa), large surface area (731 m2 g–1), and abundant pores (macropores, mesopores, and micropores). The determined relaxation time constant (τ0 = 0.35 s) indicated that the consecutive porous structure is conductive to fast ion diffusion. The heteroatoms introduced via the biomass itself not only conferred additional pseudo-capacitance but also improved the surface wettability. Thus, when carbonized at 750 °C, the 3DPC possessed high specific capacitance, excellent rate capacity (82.8% retention when the current density was increased to 20 A g–1), and outstanding cycling stability (96.3% after 10,000 cycles) in aqueous electrolytes. In an all-solid-state symmetric capacitor, 3DPC delivered high energy and power densities.