PC Bond Research Articles

Phosphor-doping modulates the d-band center of Fe atoms in Fe-N4 catalytic sites to boost the activity of oxygen reduction

Regulating the electronic structure by phosphor-doping is a preferred strategy to boost the performance of carbon-based catalysts for oxygen reduction reaction (ORR). Here, a porous Fe, P, N-codoped carbon catalyst (PCF-FeTz-900) is designed by a phytic acid-assisted thermal etching strategy, in which P atoms are first doped into the carbon matrix to form a stable PC bond, and then FeN4 sites are produced from Fe-2,4,6-Tris(2-pyridyl)-s-triazine complex (Fe-TPTz). Theoretical calculations suggest that the electrons are transferred from the doped P atom to the neighboring FeN4 sites, which facilitates the ORR at the Fe sites by reducing the energy barrier and the adsorption energy of intermediates. Additionally, the P-doped FeN4 (FeN4P) structure manifests a lower free energy difference than that of FeN4 and the d-band center of Fe is also lowered, which further ensures its higher ORR catalytic ability. As a result, the PCF-FeTz-900 catalyst exhibits superior ORR activity and stability in alkaline electrolyte, and the assembled primary zinc-air battery shows greater performances compared to the commercial Pt/C catalyst. This work can provide an effective pathway for modulating the performance of doped-carbon materials in energy conversion devices.

High performance carboxymethyl cellulose- polyethylene oxide polymer binder for black phosphorus anode in lithium-ion batteries

Black phosphorus (BP) is regarded as a promising anode material due to its high theoretical specific capacity and fast charging safety. However, the problems of huge volume expansion and moderate electrical conductivity may restrict its performance. In this work, we present a novel 3D network binary polymer binder synthesized from carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) for adapt to lithium-ion batteries of BP and graphite (G) composite anode (BP-G). There are the following characteristics of the binder: CMC and PEO are crosslinked through intermolecular forces; while CMC and PEO are connected to BP through strong intermolecular forces, respectively; BP and graphite are connected through PC and POC bonds to form composite anode. So as to form a sturdy structure and effectively accommodate the volume expansion of BP during charging-discharging processes, while avoiding loss of electrical contact between electrode components. Accordingly, the lithium-ion battery shown an excellent electrochemical performance, such as a high initial discharge capacity of 1602 mA h g−1 at 0.5 A/g.

Constructing CoP[sbnd]C/g-C3N4 nanocomposites with P[sbnd]C bond bridged interface and van der Waals heterojunctions for enhanced photocatalytic H2 evolution

Enhancing the charge transmission rate at the interface of transition metal phosphide cocatalysts is an efficient technique to reinforce the photocatalytic activity action of semiconductors, but achieving a faster interface charge transfer rate remains a challenge. This paper reported the coupling of a two-dimensional carbon layer supported CoP (CoPC) as a non-noble metal heterostructure catalyst and a two-dimensional porous graphite carbon nitride (CN) photocatalyst to enhance the transmission rate of photogenerated carriers at the interface. Detailed characterizations and mechanism research have confirmed that the PC bond and Van der Waals heterojunction at the interface function as a novel charge transmission channel, which facilitates the effective transfer of photogenerated carriers from CN to CoP. Furthermore, the large contact area exhibited by the 2D/2D Van der Waals heterojunction offers an increased number of active sites for hydrogen evolution reactions. Consequently, the composite material (CoPC/CN) formed by the coupling of CoPC and CN has an enhanced H2 production rate of 1503 μmol∙g−1∙h−1 (AQY: 3.03 % at 400 nm) and favorable H2 production stability under visible light irradiation. This investigation not only provides a new idea for the regulation of interface charge transfer pathway but also offers new inspiration for the photocatalytic system's design with the synergistic impacts of 2D/2D VDW heterojunction and chemical bonds.

Recyclable flame retardant phosphonated epoxy based thermosets enabled via a reactive approach

The development of reusable fire-safe polymers with a prolonged lifetime heralds the switch for a transition towards circular economy. In this framework, we report a novel phosphonated thermoset which is composed of networked phosphonate esters containing both PC and PO bonds. Employing a simple one-pot, two-step synthetic methodology, oxirane groups of the epoxy resin were partially reacted with various amounts of reactive bis H-phosphonate monomer, and cured with a cycloaliphatic hardener to obtain multifunctional thermosets with up to 8% phosphorus (P) content. Though 2.5% P was adequate to achieve good flame retardancy, a concentration > 5% P was necessary for accomplishing material reprocessability and recyclability. These phosphonated thermosets exhibited high Tg (94 °C – 140 °C) and good thermal stability. Fire performance of the thermoset with 2.5% P via cone calorimetry showed effective reduction in the peak heat release rate (pHRR, 75%) and significant inhibition of total smoke production (TSP, 72.5%), which was attributed to the gas and condense phase actions of the phosphonate moieties. This thermoset was explored as a transparent fire-safe coating on wood where an intumescent flame retardant mechanism was observed. The phosphonated thermoset with higher P content (6%) demonstrated excellent damage reparability and thermomechanical reprocessability driven by transesterification induced network rearrangement. This thermoset was used for manufacturing flax fiber reinforced composite, to demonstrate its future application as a polymer matrix for composite materials.

Black phosphorus stabilized by titanium disulfide and graphite via chemical bonds for high-performance lithium storage

Black phosphorus (BP) anode has received extensive attentions for lithium-ion batteries (LIBs) due to its ultrahigh theoretical specific capacity (2596 mAh g−1) and superior electronic conductivity (≈102 S m−1). However, the enormous volume variations during lithiation/delitiation processes greatly limit its applications. Herein, a new BP-titanium disulfide-graphite (BP-TiS2-G) nanocomposite composed of BP, titanium disulfide and graphite has been prepared by a facile and scalable high-energy ball milling method. The experimental data proves that PC and PS bonds have been successfully introduced at the interface, which can effectively maintain the structural integrity of the BP-TiS2-G electrode when evaluated as an anode material for LIBs. In addition, lithium-ion diffusion kinetics have been demonstrated to be enhanced from the synergistic effect of PC and PS bonds. As a result, the BP-TiS2-G anode shows outstanding cycling stability (906.2 mAh g−1 after 1300 cycles at 1.0 A g−1) and superior rate performance (313.8 mAh g−1 at 10.0 A g−1). Our work shows the synergistic effects of different chemical bonds to stabilize BP can be a potential strategy for the development of high-performance alloy-type anodes for rechargeable batteries.

The surface functional modification of Ti3C2Tx MXene by phosphorus doping and its application in quasi-solid state flexible supercapacitor

The surface modification of MXene by heterogeneous atoms shows great potential in improving the charge storage capacity of MXene. Herein, a strategy of rapid in-situ phosphorus doping at low temperature is demonstrated for preparing functionalized Ti3C2Tx MXene (Ti3C2Tx-P) using sodium hypophosphate as phosphorus source. The phosphorus doping can increase the layer spacing of Ti3C2Tx and yield PO and PC bonds in Ti3C2Tx, resulting in more rapid paths for the migration of electrolyte ions into electrode and more active sites for pseudocapacitance effects. As flexible electrode of supercapacitor, the specific capacitance of Ti3C2Tx-P reaches as high as 476.9F g−1 (745.4F cm−3), which is far larger than that of the raw Ti3C2Tx (344.4F g−1, 438.5F cm−3). In addition, a flexible quasi-solid supercapacitor device assembled by Ti3C2Tx-P film shows high specific capacitance of 103F g−1 at 5 mV s−1. When the power density is 250 W kg−1 and 10000 W kg−1, the corresponding energy density reaches 15.8 Wh kg−1 and 6.1 Wh kg−1, respectively. Therefore, our work not only reveals the role of P atom doping in improving the structure, composition and electrochemical performance of Ti3C2Tx, but provides a method for surface modification and functionalization of MXene materials.

Nonradiative electron-hole recombination dynamics in edge-selective phosphorus-doped graphene quantum dots for energy conversion applications

Doping with heteroatoms is an effective way to modify the electronic structures and photophysical properties of graphene quantum dots (GQDs). However, there are few studies on phosphorus-doped GQDs (P-GQDs), especially with respect to the dynamics of electron-hole recombination, which plays a crucial role in the energy conversion performance of P-GQDs. In the current study, we investigate the effect of phosphorus-containing groups (i.e., phosphine oxide, phosphonic acid, phosphate, and phosphinic acid) on the electronic structures, optical properties, and dynamics of nonradiative recombination of P-GQDs with different edge coverages and structural symmetries. Our results show that P-doping disrupts the integrity of the conjugated π-skeleton of carbon system, leading to the localization of electrons in P-GQDs. The phosphine oxide has a stronger effect on the sp2 bonding environment of the carbon skeleton, leading to a greater impact on the geometrical and electronic structures of the P-GQDs than in the other P-functionalized systems. The increase in the passivation density of phosphinic acid leads to localization of electron and hole densities at the periphery of the GQDs. In addition, the PC bond in phosphonic acid dramatically increases the electronic coupling, leading to the fastest non-radiative decay rate. The overall photovoltaic performance of phosphate- and phosphine oxide-functionalized GQDs are better than the other P-functionalized GQDs. Our calculations provide guidance for the rational design of P-doping configurations in P-GQDs to improve their energy conversion efficiency.

Phosphorus stabilization of the carbene function in P-analogues of non-cyclic carbenes, N-heterocyclic carbenes and cyclic(alkyl)-(amino)carbenes − an assessment on basis of geometry, 13C, 31P chemical shifts and the anisotropy effects of the carbene electron deficient centres

The spatial magnetic properties, through-space NMR shieldings (TSNMRS), of the P-analogues of non-cyclic, N-heterocyclic carbenes (NHCs) and cyclic (alkyl) (amino)carbenes (CAACs) have been calculated using the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept and the results visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values (actually the anisotropy effects experimentally measurable in 1H NMR spectroscopy) are employed to qualify and quantify the position of the present mesomeric equilibria (P-carbenes ↔ P-ylides ↔ P-acetylenes/P-allenes). Results are confirmed by geometry (bond angles and bond lengths), the 31P and the 13C chemical shifts of the electron-deficient carbene centres. It was found out that the π-donor and σ-acceptor power of phosphorus in planar and not pyramidalized PR2 substituents to stabilize P-carbenes (compared with NR, OR, SR and Hal substituents) is only minor, but complete PC bonds along sole ylide-like mesomeric contributors are existing. A phosphorus carbene stabilization mechanism, not yet specified, in addition or different to π-donation, is badly needed.

Transformation and fate of non-reactive phosphorus (NRP) in enhanced biological phosphorus removal process with sidestream phosphorus recovery

Recovery of phosphorus (P) from wastewater can help establish a new P cycle. However, there are many P forms in wastewater, not always in reactive forms, which are the most suitable for direct recovery. The enhanced biological phosphorus removal process with sidestream phosphorus recovery (EBPR-SPR) is an effective way to remove and recover P resources in wastewater, but there is a lack of research on the transformation and fate of non-reactive phosphorus (NRP) in it. This study selected four model NRP to investigate their transformation and fate in an EBPR-SPR process. The transformation of NRP in pure water and activated sludge under anaerobic and aerobic conditions were compared. The effects of Ca/P ratio and pH on NRP recovery were studied, and the recovery products of NRP were characterized. It was found that NRP containing phosphoanhydride and phosphoester bonds were more easily hydrolyzed to reactive P (RP) than that containing PC bonds. NRP will be adsorbed and accumulated by activated sludge, and activated sludge will accelerate the conversion of NRP to RP. Tripolyphosphate can form complex precipitation with Ca2+. When multiform P co-existed, Ca2+ preferably complexed with polyphosphate, which harmed RP recovery. The conversion of NRP should be strengthened to recover more P in wastewater. The effect of NRP should be considered when recovering P from wastewater.

Study on lithium storage performance of plum-putting-like CoP nanoparticles embedded in N, P co-doped porous carbon

Metallic cobalt phosphide (CoP) has a higher theoretical capacity than traditional graphite anode due to its unique lithium storage mechanism. However, CoP can not be directly used as anode material because of its insufficient conductivity and serious volume expansion in cycles. Here, CoP was modified by nanocrystallization and carbon compositing methods, and plum-putting-like CoP nanoparticles embedded in nitrogen and phosphorus co-doped porous carbon (CoP@NPPC) were prepared. The successful nanocrystallization strategy leads to the formation of tiny CoP nanodots smaller than 20 nm and nanoparticles smaller than 100 nm, which uniformly disperse in the simultaneously formed N and P co-doped porous carbon. The CoP nanodots and nanoparticles are chemically bonded to carbon by PC bond, which is theoretically proved to bring increased density of states of CoP at Fermi level, responsible for its conductivity improvement. At the same time, the nanocrystallization of CoP also alleviates its volume expansion and particle breakage after numbers of lithiation reactions, thus improving the electrode stability in cycles. Based on the above characteristics, CoP@NPPC achieves a high capacity retention rate of 95.9% and a remaining specific capacity of 380.1 mAh g−1 after 1800 cycles at the current density of 5 A g−1. Moreover, the preparation of CoP@NPPC is achieved by a simple carbothermic treatment using a highly safe flame-retardant material as both P and C sources, which avoids the release of highly toxic phosphine that are usually involved in traditional phosphorization methods.

Self-supporting ZnP2@N, P co-doped carbon nanofibers as high-performance anode material for lithium-ion batteries

Searching for high specific capacity anode materials with an optimized structure to achieve high energy density, long cycling life-span, and high rate performance for lithium-ion batteries (LIBs) is a pressing assignment. Metal phosphides have aroused much attention, however, enormous volume variations, poor electrical conductivity, and aggregation of nanoparticles hamper their practical applications. Herein, ZnP2 nanoparticles grown on N, P co-doped carbon nanofibers (ZnP2 @NPCNFs) composite synthesized by electrospinning and heat treatment is reported to directly act as binder-free anode in LIBs. The 3D self-standing ZnP2 @NPCNFs featuring good flexibility can not only boost conductivity and alleviate the volumetric fluctuations in the cycling course, but also buffer the agglomeration and pulverization of nanoparticles. Lithium storage of ZnP2 @NPCNFs electrode obey the conversion reaction mechanism. Besides, the additional lithium intercalation active sites created by the doped-nitrogen and the existence of PC bond along with the space-confined effect of NPCNFs are conjointly beneficial to endow the ZnP2 @NPCNFs electrode with distinctive electrochemical properties. When assembled as the anode, the ZnP2 @NPCNFs electrode reached a high reversible capacity of 746 mA h g−1 after 100 cycles at 0.2 A g−1 and 406.49 mA h g−1 after 1000 cycles at 2 A g−1. Electrochemical tests manifest that most of the capacity contribution comes from capacitive process. Moreover, the similar superior electrochemical performances are obtained in the LiFePO4//ZnP2 @NPCNFs full cell. Generally, this study widens researchers’ horizons to conceive rational structure of metal phosphides anodes in LIBs with high capacity conservation.

A Theoretical Study of the Occupied and Unoccupied Electronic Structure of High- and Intermediate-Spin Transition Metal Phthalocyaninato (Pc) Complexes: VPc, CrPc, MnPc, and FePc.

The structural, electronic, and spectroscopic properties of high- and intermediate-spin transition metal phthalocyaninato complexes (MPc; M = V, Cr, Mn and Fe) have been theoretically investigated to look into the origin, symmetry and strength of the M–Pc bonding. DFT calculations coupled to the Ziegler’s extended transition state method and to an advanced charge density and bond order analysis allowed us to assess that the M–Pc bonding is dominated by σ interactions, with FePc having the strongest and most covalent M–Pc bond. According to experimental evidence, the lightest MPcs (VPc and CrPc) have a high-spin ground state (GS), while the MnPc and FePc GS spin is intermediate. Insights into the MPc unoccupied electronic structure have been gained by modelling M L2,3-edges X-ray absorption spectroscopy data from the literature through the exploitation of the current Density Functional Theory variant of the Restricted Open-Shell Configuration Interaction Singles (DFT/ROCIS) method. Besides the overall agreement between theory and experiment, the DFT/ROCIS results indicate that spectral features lying at the lowest excitation energies (EEs) are systematically generated by electronic states having the same GS spin multiplicity and involving M-based single electronic excitations; just as systematically, the L3-edge higher EE region of all the MPcs herein considered includes electronic states generated by metal-to-ligand-charge-transfer transitions involving the lowest-lying π* orbital (7eg) of the phthalocyaninato ligand.

Direct observation of dynamic interfacial bonding and charge transfer in metal-free photocatalysts for efficient hydrogen evolution

Herein, we employed a simple approach for incorporating covalent triazine frameworks (CTF) with ultrathin black phosphorus (BP) nanosheets, resulting in one of the highest hydrogen evolution activities (17.1 mmol h−1 g−1) among all reported metal-free photocatalysts. More importantly, a detailed mechanistic study on dynamic charge transfer and interfacial bonding was conducted by an in-situ irradiation X-ray photoelectron spectroscopy (SI-XPS). The related results clearly reveal that the interfacial PC bonding between ultrathin BP and CTFs is crucial for promoting both photocatalytic activity and stability. More specifically, under light irradiation, the interfacial PC bonds were remarkably enhanced, which efficiently accelerate the photo-generated electron transfer from CTF to BP surfaces for hydrogen evolution reactions. Moreover, owing to the electron enrichments on BP for effectively restraining surface oxidation, the photocatalytic stability of BP/CTF has also been significantly improved. This work not only reported an effective way for fabricating highly efficient metal-free photocatalysts, but also provided the unique insights into the fundamental understanding of the intrinsic mechanisms during photocatalytic reactions.

Construction of graphite oxide modified black phosphorus through covalent linkage: An efficient strategy for smoke toxicity and fire hazard suppression of epoxy resin

The black phosphorus (BP) can be compounded with other two-dimensional materials with flame retardant effect to achieve better synergistic effect. Herein, the multifunctional BP-RGO nanohybrids was fabricated by solvothermal strategy to improve the dispersion state of BP in epoxy resin (EP) and enhance its fire safety performance, where the reduced graphene oxide (RGO) was attached on the surface of BP via PC and POC bonds. With the incorporation of 2.0 wt% BP-RGO into EP matrix, 54.4 % reduction in total heat release (THR) was achieved along with 55.2 % decrease in peak heat release rate (PHRR) compared with neat EP. As a similar trend, the toxic CO and aromatic compounds were significantly inhibited, and the maximum decrease (28.5 %) in total smoke production (TSP) was achieved, indicating the enhanced fire safety performance of EP nanocomposites. These positive results is attributed to the synergistic effect of physical nano-barrier, free radicals trapping and char formation between BP and RGO components. Meanwhile, the EP/BP-RGO2.0 nanocomposites exhibited satisfying air stability even after being immersed in water for a month. This work enriches the strategies for enhancing the air stability of BP, and confirms its potential for smoke toxicity and fire hazard suppression in polymer nanocomposites.

Photoreaction of anthracenyl phosphine oxides: Usual reversible photo- and heat-induced emission switching, and unusual oxidative P[sbnd]C bond cleavage

Anthracenyl(diphenyl)phosphine oxide and dianthracenylphenylphosphine oxide as photoactive compounds have been synthesized. Anthracenyl group of these compounds indicate the multi-functional roles such as an emission component, a photodimerization component, and a leaving group. When the light irradiation was performed under an oxygen atmosphere, photo-oxidative PC bond cleavage to leave the antharacenyl group was observed. Moreover, phosphonyl radical was produced and then PP bond formation to form diphosphane was observed.

High variety of coordination modes of π-conjugated phospholes in dinuclear rhenium carbonyls. Fluxional behavior of σ,π-complexes

A variety of dirhenium carbonyl complexes containing π-conjugated phosphole derivatives were obtained from reaction of [Re2(CO)8(CH3CN)2] with each of the following phospholes: 2,5-bis(2-thienyl)-1-phenylphosphole (btpp), 2,5-bis(2-pyridyl)-1-phenylphosphole (bpypp) and 1,2,5-triphenylphosphole (tpp). The π-conjugated phospholes were found to behave as two-, four- or six-electron donor ligands via σ or σ-π interactions with the metal centers, presenting bridging or chelating coordination modes as determined by spectroscopic methods and single crystal X-ray diffraction analysis. Metal-metal bond cleavage was evidenced when btpp was used, leading to a mono-substituted mononuclear complex. Variable-temperature 1H NMR studies for σ,π-complexes showed a fluxional behavior due to the restricted rotation around the PC and CC bonds of the 1,2,5-trisubstituted phosphole ring.

Material structure and chemical bond effect on the electrochemical performance of black phosphorus-graphite composite anodes

Black phosphorus (BP) is a little-studied but promising next-generation anode material for high-energy density Li-ion and Na-ion batteries. To understand the relationship between material property and electrochemical performance, black phosphorus-graphite (BP-G) composite materials are synthesized with two different BP-G molar ratios. This study demonstrates that the crystal structure and PC bond of BP-G composites are affected by the BP-G molar ratio, which are directly correlated to cycle stability and the lithiation/delithiation process. BP0.9G1 shows a medium-range ordered structure, retaining some features of BP and having fewer or weaker PC bonds. In contrast, BP0.3G1 has an amorphous-like structure with robust PC bonds, which is helpful in withstanding the large volume change upon lithiation or delithiation. As a result, fracture and pulverization of particles, which are clearly seen in BP0.9G1 electrode, are scarcely observed in the cycled BP0.3G1 electrode. The possibility of mechanical failure in the BP-based electrode induced by BP's hydrophilic nature and the formation of Cu3P is also discussed. This work not only contributes to improving the current understanding of phosphorus-based anodes, but also provides direct evidence of fracture and pulverization of BP particles during cycling.

Thermal decomposition of polyimides containing phosphine-oxide units

This work details analyses of the thermal decomposition behaviour of three phosphine-oxide containing aromatic processable polyimides. The polymers exhibited high thermal stability with initial decomposition temperatures in the range of 473–483 °C and a char residue at 900°C in the domain of 48.58–58.38%. The values of non–isothermal decomposition kinetic parameters were determined using the Friedman isoconversional method, as recommended by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The data evidenced a complex decomposition process of the main chain, being probably initiated by the cleavage of the weaker PC bonds, followed by the decomposition of the macromolecular backbone. The volatile products formed during the thermal decomposition of polyimides were analysed by TGA-FTIR. All spectra evidenced peaks associated with water, CO2, CO and aliphatic and aromatic decomposition products predominant from 500° to 800 °C. By using Py-GC–MS studies the fragments originating from the thermal decomposition of the polyimides up to 600 °C were identified. Based on these data, it was suggested that the thermal decomposition pathways of the three polyimides undergoes the same mechanism. Additionally, an oversimplified decomposition mechanism for the polyimides was proposed. The morphology of the char residue obtained after TGA experiments showed a continuous and dense structure. The EDX mapping identified the C, N, O and P atoms uniformly dispersed in the residual char surface.

Trihexyl phosphate to trihexyl phosphine oxide: Diverse effect on extraction behavior of actinides

To delineate the effect of PC bond of phosphorous esters on the extraction of actinides, diverse organophosphorus esters (trihexyl phosphonate (THP), dihexylhexyl phosphonate (DHHP), hexyldihexyl phosphinate (HDHP) and trihexylphosphine oxide (THPO)) were synthesized and spectroscopically characterized. The physical properties such as density, viscosity are reported in subsequent sections. The extraction behaviour of the ligands were evaluated for U(VI), Th(IV) and Am(III), as well as acid uptake as a function of nitric acid ranging from 0.01–6M. Distribution ratios for U(VI), Th(IV) and Am(III) indicate a large difference in solvent strength among these compounds. Replacement of POC group by PC group i.e. introduction of electron donating group greatly increases the solvent strength. The P=O stretching frequency can be correlated with the solvent strength of these compounds, and the conclusions are further supported by density functional theory calculations.

Chemical-free fabrication of N, P dual-doped honeycomb-like carbon as an efficient electrocatalyst for oxygen reduction

Heteroatom-doped nanoporous carbons are now emerging as alternatives to platinum and its alloys as electrocatalysts to facilitate oxygen reduction reaction in metal-air batteries and fuel cells. However, the synthesis of nanoporous carbons usually involve in complicated procedures and intensive chemicals, which may dramatically raise their manufacture cost that even surpasses that of precious platinum. Herein, we demonstrate the single-step, chemical-free fabrication of N, P dualdoped honeycomb carbon that has hierarchically porous structure and oxygen electrocatalysis activity close to the benchmark Pt/C. This material was fabricated through the direct pyrolysis of popcorn in a static, semi-opened environment. With this strategy, nitrous and phosphoric groups from proteins and phosphates within the popcorn are condensed with graphitic matrix to form NC and PC bonds, and pyrolysis byproducts (such as H2O and CO2) can etch disordered carbon domains to form hierarchical pores and edge carbons. Practical test of this honeycomb carbon as air electrode of a primary Zn-air battery shows an open-circuit potential of 1.44V and peak power density of 36.6mWcm−2 that is even better than Pt/C. The impact of this work is that it will facilitate the targeted design and cost-saved fabrication of metal-free catalysts for electrocatalytic applications.