Direct Pyrolysis Method Research Articles

Deep eutectic solvent-mediated synthesis of CuCo2O4 @ Sargassum tenerrimum derived carbon heterostructure as an efficient electrocatalyst for oxygen and hydrogen evolution reactions

Developing bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through simple, economical, and innovative methods is vital for sustainable energy conversion. Here, we showcase a green and sustainable approach for synthesizing CuCo₂O₄ - Sargassum Tenerrimum derived carbon composites (CCST) directly from fresh seaweed and a deep eutectic solvent (DES), marking its initial application in HER/OER. The successful transformation of seaweed and metal precursors into CCST was accomplished using a direct pyrolysis method at 900 °C in an inert atmosphere. Here, Seaweed granules acted as the carbon source, with DES employed for its multifunctional properties, including serving as a solvent, a structural template, and a catalyst for fostering material development. When these materials were assessed as electrocatalysts for OER in 1 M KOH media, the optimal catalyst (CCST-9 (1:2)) exhibited a low overpotential of 381 mV at 10 mA cm−2 with a Tafel slope of 44 mV dec−1. In addition, the same material achieved low overpotential of 383 mV at 10 mA cm−2 with a Tafel slope of 100 mV dec−1 when tested as an electrocatalyst for HER in 0.5 M H2SO4 media. Interestingly, CCST-9 (1:2) demonstrated excellent long-term stability in OER in 1 M KOH during a 24-h chronoamperometry test, with only a minor reduction in current density. The present study contributes new perspectives to the development of scalable and high-performance bifunctional catalysts, achieved through an environmentally friendly and cost-effective synthetic strategy.

Study on the adsorption performance and regeneration of lignin-derived graphitic carbon for H2S

In pursuit of effective adsorption materials for malodorous gases such as H2S and to broaden the utilization avenues of lignin waste, this study employed the direct pyrolysis method to synthesize three types of alkali lignin graphitized carbons, namely C-800, KC-700, and KEC-700. Among them, KEC-700 exhibits a high specific surface area of 1672.9 m2/g, significantly superior H2S adsorption performance compared to other materials, an adsorption breakthrough time of up to 220 min, and a sulfur capacity of 67.1 mg/g. Structural analysis showed that the more oxygen-containing functional groups of lignin charcoal and the larger specific surface area facilitated the adsorption of H2S. After reaching adsorption saturation, the degree of graphitization of lignin carbon diminishes. The H2S adsorption products primarily manifest as elemental sulfur and sulfate within the pores of lignin carbon measuring less than 2 nm. Through thermal regeneration, the charcoal effectively eliminates the elemental sulfur adsorption product. Nevertheless, sulfate removal proved unsatisfactory, as the adsorption efficiency of KEC-700 following two thermal regenerations was approximately 41% of that observed for fresh samples.

Boron and Fluorine Co‐Doped Graphene/Few‐Walled Carbon Nanotube Composite as Highly Active Electrocatalyst for Oxygen Reduction Reaction

Functionalization of nanocarbon materials with heteroatoms is of paramount interest as doping of carbon with electron withdrawing groups results in change of electrochemical properties of the potential catalyst. Adding fluorine, as the most electronegative element into the doping process next to boron is expected to have significant effect on the design of novel nanocarbon‐based electrocatalysts. In this paper boron and fluorine co‐doped reduced graphene oxide/few‐walled carbon nanotube (BF‐rGO/FWCNT) catalyst are synthesized via simple and low‐cost direct pyrolysis method using boron trifluoride diethyl etherate (BTDE). Composition analysis confirmed that boron and fluorine have been grafted onto the carbon support. Rotating disk electrode (RDE) measurements revealed that BF‐rGO/FWCNT has remarkable electrocatalytic activity toward the oxygen reduction reaction (ORR) both in alkaline and acid media. The onset potential of the best BF‐rGO/FWCNT catalyst was 50 mV more positive in alkaline and 600 mV more positive in acidic media compared with un‐doped rGO/FWCNT. The half‐wave potential was 100 mV more positive in alkaline media and 700 mV more positive in acidic media in comparison with un‐doped rGO/FWCNT.

Removal of methylene blue azo dye from aqueous solution using biosorbent developed from floral waste

Aim: The present study was carried out to prepare biosorbent from temple floral waste (Tagetes erecta) by pyrolysis and chemical activation method for removal of methylene blue dye from aqueous solution. Methodology: Floral waste of Tagetes erecta collected from the temples were segregated, washed and dried to form biochar by direct pyrolysis and chemical activation method. Followed by physio-chemical analysis of biosorbents the most efficient biochar was selected for the removal of methylene blue dye from aqueous solution. The adsorbent efficiency and percentage removal of methylene blue dye was studied using various doses of biochar (10, 20, 30, 40, 50, 60, and 70 mg 100 ml-1,), effect of pH (2.0 to 4.0, 6.0 to 8.0, and 10.0 to 12.0) and effect of contact time etc. Results: The comparative physio-chemical analysis of the bio chars suggested that the activated charcoal made from temple flower waste by the direct pyrolysis method showed better performance, with its low moisture content (5.3%), low ash content (4.3%), higher yield, larger surface area, and higher porosity (65.3%) as compared to the biochar obtained from chemical activation. The percent adsorption significantly increased (p<0.05) from 76% to 87.0% on increasing biochar dose from 10.0 to 70.0 mg 100 ml-1. On increasing the pH of the solution from 4.0 to 6.0, Methylene blue removal significantly increased (p<0.05) from 88.0% to 91.0%. Interpretation: It is possible to manage floral waste from temples in a sustainable and environmentally responsible manner by converting it into biochar and using it for the treatment of waste water in order to eliminate hazardous dyes. Key words: Activated carbon, Azo dye, Bioremediation, Biochar, Floral waste, Methylene blue

Intralayered ostwald ripening impelled nanoarchitectonics of MXene nanorods on MXene nanosheets with boron carbon nitride for robust supercapacitor application

Utilizing 2D layered materials as one of the composite's members in the synthesis of active material for supercapacitors is acquiring imperative attention on account of the extraordinary outcomes due to their wholesome hale structural and electrochemical affinity. Here, by rousing from intralayer ostwald ripening impelled growth of in situ spawned 1D Nb2C rods on 2D Nb2C sheets, in short form (h)Nb2C are generated via hydrothermal low temperature treatment without, which overwhelms the electrochemical performance of pure 2D MXene sheets. Later the residue less direct pyrolysis method was adopted for the in-situ development of 2D BCN nanosheets over MXene, 1D-2D/2D MXene/BCN hybrid nanoarchitectonics. The process method enabled the interrelated structural growth of BCN particles on MXene and helps in empowering the pseudocapacitive activity of the enlarged portion of Nb sites by the removal of the terminal groups. Thus, the fabricated 1D-2D/2D Nb2C/BCN (NBCN) electrode showed a specific capacitance of 765 F g− 1 at 2 A g− 1 current density with a high specific energy of 35 Wh kg−1. Eventually, the solid-state supercapacitor device further withstands 100,000 cycles displaying high efficiency and ∼100% retention. Henceforth, the 1D-2D/2D heterostructures with magnificent electrochemical properties can act as a feasible energy storage system.

Insight into the Key Restriction of BiVO4 Photoanodes Prepared by Pyrolysis Method for Scalable Preparation

AbstractBismuth Vanadate (BiVO4) photoanode has been popularly investigated for promising solar water oxidation, but its intrinsic performance has been greatly retarded by the direct pyrolysis method. Here we insight the key restriction of BiVO4 prepared by metal–organic decomposition (MOD) method. It is found that the evaporation of vanadium during the pyrolysis tends to cause a substantial phase impurity, and the unexpected few tetragonal phase inhibits the charge separation evidently. Consequently, suitably excessive vanadium precursor was adopted to eliminate the phase impurity, based on which the obtained intrinsic BiVO4 photoanode could exhibit photocurrent density of 4.2 mA cm−2 at 1.23 VRHE under AM 1.5 G irradiation, as comparable to the one fabricated by the currently popular two‐step electrodeposition method. Furthermore, the excellent performance can be maintained on the enlarged photoanode (25 cm2), demonstrating the advantage of MOD method in scalable preparation. Our work provides new insight and highlights the glorious future of MOD method for the design of scale‐up efficient BiVO4 photoanode.

Insight into the Key Restriction of BiVO4 Photoanodes Prepared by Pyrolysis Method for Scalable Preparation.

Bismuth Vanadate (BiVO4 ) photoanode has been popularly investigated for promising solar water oxidation, but its intrinsic performance has been greatly retarded by the direct pyrolysis method. Here we insight the key restriction of BiVO4 prepared by metal-organic decomposition (MOD) method. It is found that the evaporation of vanadium during the pyrolysis tends to cause a substantial phase impurity, and the unexpected few tetragonal phase inhibits the charge separation evidently. Consequently, suitably excessive vanadium precursor was adopted to eliminate the phase impurity, based on which the obtained intrinsic BiVO4 photoanode could exhibit photocurrent density of 4.2 mA cm-2 at 1.23 VRHE under AM 1.5 G irradiation, as comparable to the one fabricated by the currently popular two-step electrodeposition method. Furthermore, the excellent performance can be maintained on the enlarged photoanode (25 cm2 ), demonstrating the advantage of MOD method in scalable preparation. Our work provides new insight and highlights the glorious future of MOD method for the design of scale-up efficient BiVO4 photoanode.

Mild pretreatment synthesis of coal-based phosphorus-doped hard carbon with extended plateau capacity as anodes for sodium-ion batteries

Hard carbon as one of the most promising anodes for sodium-ion batteries (SIBs) has received much attention in terms of its high low-voltage plateau capacity. Precursors play an important role in synthesizing hard carbon with low cost and high performance. It is interesting to convert industrial coal to hard carbon with a high yield for energy storage owing to environmental and energy concerns. However, some small molecular organics and inorganics impurities in coal seriously affect the properties of hard carbon by the direct pyrolysis method. Herein, coal-based phosphorus-doped hard carbon is synthesized through a mild pretreatment method of using NaNO3 and H3PO4. This mild pretreatment can not only purify the coal to obtain the high reversible capacity of 284.4 mAh g−1, but also achieve homogeneous phosphorus doping simultaneously. Interestingly, the low-voltage plateau capacity increases during continuous cycling, while the high-voltage sloping capacity does not change obviously, due to the enlargement of the interlayer spacing induced by continuous electrochemical activation of P-doped micron-sized hard carbon material could provide more Na+ intercalation sites. The proportion of plateau capacity of this coal-based hard carbon increases to 54.31% after 500 cycles at 100 mA g−1, which is 13% larger than that of unpretreated coal-based hard carbon.

Highly uniform Pd nanoparticles supported on Co-metal organic frameworks-derived carbon as HER electrocatalysts

Non-Pt-based catalysts with high efficiency and stability have good research prospects for effective hydrogen production. Metal organic framework (MOF)-derived carbon materials are considered to be ideal catalyst supports due to their specific structure and tunable chemical composition. Here, we report a series of Pd-doped Co-MOF-derived carbon materials catalyst (Pdx/Co@NC) by direct pyrolysis method. The optimized electrocatalyst exhibits high HER performance in 0.5 M H2SO4, in the field of low overpotential (η10 = 54 mV) and small Tafel slopes (42 mV dec−1). It is comparable to the commercial Pt/C catalyst and even better than the Pd-based catalyst reported in many literatures. This study can make Pd-based electrocatalysts in electrochemical energy storage, compared with other catalysts in price and performance, which provides some ideas.

The preparation of bifunctional Co-N co-doped carbon with bamboo-like hollow tubular as an efficient electrocatalyst for oxygen reduction and methanol oxidation reaction

• Bamboo-like hollow tubular Co-N-C was prepared by direct pyrolysis method. • The Co-N-C catalyst exhibits a high specific surface area. • The Pt@Co-N-C has a high electrochemical surface area. • The Co-N-C and Pt@Co-N-C exhibit excellent ORR and MOR activity and stability. Catalysts with distinguished properties and stability are very important for the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) of fuel cells. Herein, we describe a convenient and efficient preparation means to synthesize a bamboo-like hollow tubulous structure Co-N co-doped carbon material (Co-N-C) via a late-model of Co-Imace coordinated compound as the precursor by direct pyrolysis. Additionally, Pt nanoparticles supported by Co-N-C catalysts (Pt@Co-N-C) were prepared using the ethylene glycol reduction procedure. The obtained catalyst exhibited an excellent electro-catalytic property for ORR in alkaline media, which possessed a more positive half-wave potential (0.868V) than commercial Pt/C (0.852V). Moreover, the Co-N-C maintained preeminent long-term stability (91.6 %) after the 21000s and also owned a stronger methanol resistance than Pt/C. The obtained Pt@Co-N-C electrocatalyst exhibited higher MOR activity (96.3 mA cm -2 ), which is 1.6 times greater than that of Pt/C, benefiting from the high electrochemical surface area of Pt@Co-N-C (68 m 2 g -1 ). Furthermore, the Pt@Co-N-C exhibited lower onset potentials, higher I f /I b ratios, and well long-term stability than Pt/C.

Molten-salts assisted preparation of iron-nitrogen-carbon catalyst for efficient degradation of acetaminophen by periodate activation

Highly efficient and stable heterogeneous catalysts were desired to activate periodate (PI) for sustainable pollution control. Herein, iron-nitrogen-carbon catalyst was synthesized using a facile molten-salts mediated pyrolysis strategy (denoted as FeNC-MS) and employed to activate PI for the degradation of acetaminophen (ACE). Compared with iron-nitrogen-carbon catalyst prepared by direct pyrolysis method (marked as FeNC), FeNC-MS exhibited superior catalytic activity due to its large specific surface area (1600 m2 g−1) and the abundance of FeNx sites. The batch experiments revealed that FeNC/PI process achieved 37 % ACE removal within 20 min, while ACE removal in FeNC-MS/PI process was 98 % under the identical conditions. Integrated with electron paramagnetic resonance tests, quenching experiments, chemical probe identification, and electrochemical experiments, we demonstrated that FeNC-MS-PI complexes-mediated electron transfer was the predominant mechanism for the oxidation of ACE. Further analysis disclosed that FeNx sites in FeNC-MS were the main active sites for the activation of PI. Additionally, FeNC-MS/PI process exhibited significant resistance to humic acid and background electrolyte, and avoided the secondary pollution imposed by Fe leaching. The possible degradation pathways of ACE were proposed. The germination experiments of lettuce seeds showed that the ecotoxicity of ACE solution was significantly reduced after treatment with FeNC-MS/PI process. Overall, this study provided a facile strategy for the synthesis of efficient iron-nitrogen-carbon catalysts and gained fundamental insight into the mechanism of PI activation by iron-nitrogen-carbon catalysts for pollutants degradation.

Nitrogen-doping hollow carbon nanospheres derived from conjugated microporous polymers toward oxygen reduction reaction

The exploitation non-precious or metal-free electrocatalysts of oxygen reduction reaction (ORR) is of significance for construction of next-generation fuel cells. In this work, hollow-spherical conjugated microporous polymers (CMPs) comprising porphyrin units were synthesized as precursors to prepare N-doping porous carbon spheres (CMP-NP-x) by a direct pyrolysis method. The as-resulted CMP-NP-x exhibited spherical morphology with hollow structure similar to that of CMPs precursors. The BET surface area of CMP-NP-x can be tailored by the pyrolysis temperature varying from 868 m2 g−1 to 1118 m2 g−1. According to XPS analysis, the pyrrolic N content in the sample decreased but the graphitic N and pyridinic N increased with increasing of the pyrolysis temperature from 800 °C to 1000 °C. Taking advantages of porous structure with large accessible surface areas and N species active sites, the resulting CMP-NP-x showed superior ORR activity and methanol tolerance to commercial Pt/C catalyst. In particular, CMP-NP-900 possesses the highest onset potential (0.930 V), half-wave potential (0.857 V) and limiting current density of 4.45 mA cm−2, compared with Pt/C catalyst and other samples, making it a promising metal-free catalyst superior to commercial Pt/C catalyst in alkalic condition.

Magnetic nano carbon balls - Synthesis and adsorption studies

Madhuca longifolia oil used as precursor oil for the synthesis of nano sized carbon balls with a size of 50 to 100 nm. An indigenously designed reactor assembly is used for this synthesis. Low temperature direct pyrolysis method is employed with the help of multi-metal catalyst derived from Alternanthera sessilis stem ash. The synthesized carbon balls have a bulk density of 0.124 g/mL and BET surface area of 805.87 m2/g. In-order to ensure the effective recovery of NCB, it is immobilized with a magnetic nano particle Fe3O4 and used for the adsorption studies of Acid Green 25 dye from aqueous solution under batch mode. Batch mode studies also proved the endothermic nature and physisorption mechanisms. The maximum Langmuir monolayer capacity of 243.90 mg/g has been achieved at a temperature of 45°C.

Nitrogen-Enriched Conjugated Polymer Enabled Metal-Free Carbon Nanozymes with Efficient Oxidase-Like Activity.

Metal-free carbon nanozymes could be promising with the unique features of intrinsic catalytic ability, structure diversity, and strong tolerance to acidic/alkaline media. However, to date, the study of metal-free carbon nanozymes fell far behind metal-based nanomaterials, in which, the majority reported much more peroxidase-like activity than other enzyme-mimicking behavior (e.g., oxidase). Thus, the exploit of high-performance carbon nanozymes is of importance but challenging. In this work, the nitrogen-rich conjugated polymer (Aza-CPs) with rigid network structure is utilized as precursor to yield N-doped carbon material QAU-Z1 in high yield via a direct pyrolysis method. Surprisingly, QAU-Z1 stood out in oxidase-like behavior, which significantly outperformed the control materials GNC-900 and QAU-Z2 with nucleobase or conjugated small molecule as precursor, respectively. More importantly, it is a crucial revelation that the catalytic performance is closely related to the change of zeta potential for carbon nanozyme during the substrate 3,3',5,5'-tetramethylbenzidine oxidation process, as well as its catalytical capacity to O2 , which could be insightful to understand the inherent mechanism. This work not only presents the potential of conjugated polymers in constructing highly efficient carbon nanozyme, but also reveals the vital role of interaction mode between the nanozyme and substrate in the catalytic performance.

Effect of hydrothermal pretreatment on pyrolyzed sludge biochars for tetracycline adsorption

In this research, two biochars derived from activated sludge (wastewater treatment plant) are prepared by two different preparation processes for the comparative studies of tetracycline (TC) adsorption. One is the two-stage process, including hydrothermal pretreatment and subsequent high-temperature pyrolysis (HSBC-600), while the other is the direct pyrolysis method (PSBC-600). Various technologies are employed to characterize physicochemical properties and structural features of the two biochars. The results indicate that hydrothermal pretreatment can increase the specific surface area (133.4 and 114.6 m2/g for HSBC-600 and PSBC-600) and pore volume (0.237 and 0.159 cm3/g for HSBC-600 and PSBC-600) of biochar. At 298 K, the qmax on HSBC-600 and PSBC-600 achieves 116.9 and 89.3 mg/g, respectively. It is noted that the Freundlich isotherm and pseudo-second-order kinetic equations better describe the adsorption behavior, indicating that the adsorption of TC onto HSBC-600 and PSBC-600 is the multi-layer adsorption and involves chemical adsorption. The thermodynamic parameters reveal that the adsorption process is spontaneous and endothermic, causing an increase in the degree of disorder. All adsorption mechanisms may be consisted of pore filling, electrostatic force, hydrogen bond, and π-π interaction. The higher adsorption capacity of HSBC-600 could be attributed to the more adsorption sites provided from high specific surface area and pore volume, in which π-π interaction plays a major role.

A life cycle assessment of hard carbon anodes for sodium-ion batteries.

Waste management is one of the biggest environmental challenges worldwide. Biomass-derived hard carbons, which can be applied to rechargeable batteries, can contribute to mitigating environmental changes by enabling the use of renewable energy. This study has carried out a comparative environmental assessment of sustainable hard carbons, produced from System A (hydrothermal carbonization (HTC) followed by pyrolysis) and System B (direct pyrolysis) with different carbon yields, as anodes in sodium-ion batteries (SIBs). We have also analysed different scenarios to save energy in our processes and compared the biomass-derived hard carbons with commercial graphite used in lithium-ion batteries. The life cycle assessment results show that the two systems display significant savings in terms of their global warming potential impact (A1: -30%; B1: -21%), followed by human toxicity potential, photochemical oxidants creation potential, acidification potential and eutrophication potential (both over -90%). Possessing the best electrochemical performance for SIBs among our prepared hard carbons, the HTC-based method is more stable in both environmental and electrochemical aspects than the direct pyrolysis method. Such results help a comprehensive understanding of sustainable hard carbons used in SIBs and show an environmental potential to the practical technologies. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)'.

Porous N, P co-doped carbon-coated ultrafine Co2P nanoparticles derived from DNA: An electrocatalyst for highly efficient hydrogen evolution reaction

A novel freeze-drying accompanied by direct pyrolysis method was conducted to fabricate porous N, P co-doped carbon-coated ultrafine Co2P nanoparticles (Co2P@NPC) using deoxyribonucleic acid (DNA). DNA, for the first time, is used as a precursor of the N, P co-doped carbon substrate, as well as an in-situ P source for the preparation of Co2P. Benefiting from the ultrafine Co2P nanoparticles and the porous N, P co-doped carbon, the Co2P@NPC shows excellent performance toward hydrogen evolution reaction (HER). Moreover, the N, P co-doped carbon shell can successfully prevent the Co2P nanoparticles from corrosion or decomposition, and it ensures the good interface stability. These results may provide a novel strategy for the design and synthesis of N, P co-doped carbon encapsulated ultrafine metal phosphides electrocatalysts.

Rapid formation of pyrogenic char (biochar) with high and low sorption capacity towards organic chemicals.

Pyrogenic char (biochar) with a high sorption capacity (B-HSC) can sequester hazardous chemicals (e.g., phenanthrene). However, when sorption inhibits bioavailability of some functional chemicals (e.g., the herbicidal efficacy of diuron in soil), biochar with a low sorption capacity (B-LSC) is required to prevent sorption effects. The pyrolytic B-HSC generation has been reported, but information on B-LSC formation is scarce. How fast B-HSC and B-LSC could be generated is unknown until now. Here, biochars were rapidly prepared (the shortest heating time reached 5min and the cooling time reached<30min) by a direct-pyrolysis method by directly exposing packaged rice straw and pine wood to 350°C, 500°C and 700°C and out-of-furnace cooling at room temperature. The sorption of diuron, phenanthrene, and twelve other chemicals was investigated. B-HSCs were obtained within 30min of rice straw pyrolysis, and the biochar Kd values quickly increased to 7-730-fold that of the raw biomass as -OH and C-O-C in (hemi)cellulose of rice straw rapidly degraded, increasing hydrophobic interactions between the char and chemicals (solubility≤82.8g/L). In contrast, B-LSCs were generated within 30min of PW pyrolysis, and the Kd values of the biochars were 0.2-3.0-fold that of the raw biomass, as the surface area development and hydrophobicity-driven sorption were probably delayed by the late degradation of lignin aromatic C-O and phenolic -OH. Biochar amendment revealed an enhancement effect of B-HSC but not of B-LSC on soil sorption. The fast formation of B-LSC and B-HSC provides a guide to develop time- and cost-effective technique in pyrolytically producing weakly or strongly sorbing biochars for organic chemical management.

Large-scale direct pyrolysis synthesis of excitation-independent carbon dots and analysis of ferric (III) ion sensing mechanism

A one-step direct pyrolysis method without any post-treatment steps and a mass yield of up to 69% was realized for preparing N-doped carbon dots (NCDs). The NCDs exhibit excellent excitation-independent blue fluorescence with quantum yield (QY) of 65.5%, and their luminescence mechanism was explored based on optical properties and structural composition, which mainly originates from surface state photoluminescence (PL). The NCDs display highly selective and sensitive detection of Fe3+ in tris-HCl buffer system, a good linear relationship between PL intensity ratios and Fe3+concentrations was obtained in concentration range of 0 to 400 μM with a low LOD of 0.703 μM. The formation of ferric hydroxide colloid is the main reason for the specific recognition of Fe3+ by NCDs, and buffer solution plays a key role in the formation of ferric hydroxide colloid and selective detection of Fe3+. The sensing mechanism is a dynamic quenching electron transfer process in the action of hydrogen bonding and colloidal adsorption. Three real water samples were applied to evaluate actual application of NCDs probe, satisfactory recoveries (93.5%–105.6%) indicate that NCDs has great practical potential for detection of metal ions in environmental water assays.

Monolayer carbon nanoshells by pyrolysis of organics

Monolayer carbon materials, including monolayer graphene, carbon nanohorn, single-wall nanotube, monolayer giant fullerenes and monolayer amorphous carbon, have been attracting great interest due to their unique physicochemical properties, and new methods for facile and large scale preparation of monolayer carbons are challenging and of great importance. Herein, N-P-doped monolayer carbon foam were prepared by a direct pyrolysis method. The aerogel-like carbon foam was composed of connected and/or fused monolayer carbon nanoshells with the size of 2−6 nm, and the hierarchically porous structure gave rise to an extremely large surface area of 2570 m2 g−1. The carbon foam was preliminarily tested as catalyst support and negative electrode material for lithium ion battery and exhibited good performance. This study would inspire further study on formation mechanism of monolayer carbon, as well as modification and functionalization of the monolayer carbon nanoshells for application in catalysis and energy conversion and storage.