Ultrathin Porous Carbon Research Articles

Boosting Zn-air battery performance: Fe single-atom anchored on F, N co-doped carbon nanosheets for efficient oxygen reduction

Sluggish oxygen reduction reaction (ORR) kinetics limit the development of metal-air batteries and fuel cells, hindering overall energy conversion efficiency. Therefore, significant research has focused on cost-effective, highly active, and exceptionally stable non-precious metal ORR electrocatalysts. This study presents the synthesis of a nanohybrid material called Fe SAs/FN-CNs. It is made up of single iron atoms embedded in ultrathin porous carbon nanosheets that are co-doped with F and N. The synthesis process involves an easy one-step pyrolysis technique without additional post-treatment. The Fe SAs/FN-CNs material is designed to function as an effective zinc-air battery ORR electrocatalyst. Based on their distinctive components and structure, the optimal Fe SAs/FN-CNs exhibit outstanding catalytic efficiency and long-lasting performance in the alkaline ORR. They have an onset potential (Eonset) of 0.95 V, a half-wave potential (E0.5) of 0.85 V, a kinetic current density (JK) of 20.49 mA cm−2 at 0.8 V, and a diffusion-limited current (Jd) of 6.2 mA cm−2. In addition, a Zn-air battery made using homemade Fe SAs/FN-CNs demonstrated a power density of 197 mW cm−2, a specific capacitance of 813.5 mAh g−1, and exceptional stability. It outperformed the commercial Pt/C by operating continuously for over 147 hours at 10 mA/cm² (discharge-charge). The Fe SAs/FN-CNs nanohybrid electrocatalyst shows great potential as an electrocatalyst for various metal-air batteries.

An Enzyme-Encapsulated MOF@MOF Nanocomposite for Detecting H2O2 Derived From Superoxide Anion Released by Mitochondria of HeLa Cells.

In this work, a horseradish peroxidase (HRP)-encapsulated metal organic framework (MOF)@MOF nanocomposite is developed for detecting H2O2 converted by dismutation of superoxide anions released from live HeLa mitochondria. Initially, an HRP-polyacrylic acid cluster is incorporated on a mesoporous, peroxidase-like Cu/Co-1,4-benzenedicarboxylate (BDC) MOF platform to avoid structural change and deactivation of HRP through its interactions with MOF metal ions. Additionally, a Cu/Co-BDC(HRP)@1,3,5-benzenetricarboxyate (BTC) core-shell MOF/MOF structure, also with peroxide-like properties, serves as a protective matrix for HRP. Then, ultrathin porous carbon shells (UPCS) are adopted to improve the electrical conductivity of the MOF@MOF. The Cu/Co-BDC(HRP)@BTC|UPCS sensing platform exhibits two linear ranges of 0.05-1 µM and 1-1000 µM with a sensitivity of 172mA mM-1 cm-2 and 1.63mA mM-1 cm-2, respectively. A limit of detection of 0.057 µM, good selectivity and stability over 35 days for H2O2 detection are also achieved. After treating the mitochondrial complex with specific inhibitors, amperometric results at the sensing platform confirmed complex I and III within mitochondria as the main electron leakage sites in the electron transfer chains. Therefore, this sensing platform provides a tool that may aid in predicting and even developing treatments for some oxidative stress diseases caused by mitochondrial abnormalities.

Ultrathin Porous Carbon Nitride Anchored with Pt Nanoclusters for Synergistic Enhancement of Hydrogen Production in Alkaline Photocatalytic Polyester Reforming.

Photocatalytic reforming (PR) of polyester waste, fueled by renewable sources like solar energy, offers a sustainable method for producing clean H2 and valuable by-products under mild conditions. The design of high-performance photocatalyst plays a pivotal role in determining the efficacy of an alkaline polyester PR system, influencing H2 generation activity and selectivity. Here, ultrathin porous carbon nitride nanosheets (UP-CN) loaded with Pt nanoclusters (Pt NCs, average diameter of 1.7nm) with uniform Pt NCs distribution are introduced. The resulting Pt NCs/UP-CN catalyst can accelerate charge and mass transfer while providing additional active sites, achieving superior H2 generation rates of 11.69mmol gcat -1 h-1 and 2923mmol gPt -1 h-1 under AM 1.5 light, which nine times higher than that of Pt nanoparticles-bulk graphitic carbon nitride composite (1.29mmol gcat -1 h-1 and 258mmol gPt -1 h-1) as counterpart. This performance also surpasses that of previously reported carbon nitride-based and TiO2-based photocatalysts. Moreover, the density functional theory calculations reveal a significant reduction in the energy barrier for the water dissociation step (H2O + * → *H + OH) at the interface between UP-CN and anchored Pt NCs, showcasing the synergistic effect between Pt NCs and UP-CN. This catalytic system also exhibits universality across various polyester plastics.

Nickel single-atom synergistic iron-nitrogen sites for efficient CO2 electroreduction at a wide potential range

Recently, diatomic site catalysts (DASCs) by introducing a second metal active site have become a research focus in electrochemical CO2 reduction reaction (eCO2RR), as can regulate electronic structure of metal centers and optimize reaction free energies. However, hitherto the studies on the origin of the outstanding performance of DASCs and the accurate identification of active centers are not still clear. Herein, we designed a nickel–iron diatomic site catalyst by loading highly dispersed iron phthalocyanine (FePc) on a nickel single-atom with ultrathin porous nitrogen-doped carbon nanosheet substrate (denoted as FePc/M-LNi-NC). Experimental and calculational results prove that the synergistic catalysis of FePc and carbon nanosheet based Ni single-atom endowed FePc/M-LNi-NC achieving excellent CO2 reduction performance with a maximum CO Faradaic efficiency of 98.8 % at –0.8 V vs. RHE. In particular, the current density of FePc/M-LNi-NC at −1.0 V vs. RHE in an H-type cell (−20.9 mA/cm2) is 5.6 times that of FePc (3.7 mA/cm2). Compared with M-LNi-NC, the potential range of FePc/M-LNi-NC when FECO above 95 % expands from 0.31 to 0.43 V. Density functional theory calculations reveal that the Fe site in FePc/M-LNi-NC has a lower free energy change for *COOH formation (ΔG*COOH) and CO desorption (ΔGCO) than Ni site, thus exhibits higher electrocatalytic activity. Furthermore, the ΔG*COOH on FePc/M-LNi-NC declines from 0.78 to 0.08 eV compared to M-LNi-NC, and the ΔGCO lowers from 1.36 to 0.33 eV compared to FePc, thus FePc/M-LNi-NC achieves high performance for eCO2RR at a wide potential range.

Potassium/cyano group co-incorporation promotes 2e− ORR selectivity in porous ultrathin carbon nitride for photocatalytic H2O2 production

Photocatalysis is a promising strategy for the production of H2O2, but the promotion of 2e− ORR selectivity remains a challenging goal in this field. Herein, Potassium (K+), cyano groups (-C≡N) and porous ultrathin structures were introduced into g-C3N4 simultaneously by the hyphenated technique of gas template method and molten salt-assisted method. The K+ and -C≡N can broaden the light absorption range, improve the reduction ability and promote electron transfer of the catalyst. Additionally, the presence of a permeable ultrathin structure plays a crucial role in improving the specificity of the 2e− oxygen reduction reaction (ORR). Benefiting from the multiple advantages, the H2O2 yield of K+ intercalated cyano-rich porous ultrathin g-C3N4 (KUCN) reached 781.39 μM with an extraordinary 2e− ORR selectivity of 94.5% (0.30 V vs. RHE). Overall, this study presents a practical approach for designing catalysts based on g-C3N4 that exhibit a high selectivity for the 2e− ORR reaction.

Ultrathin porous carbon nanosheets with enhanced surface energy storage for high-performance sodium-ion batteries

Ultrathin porous carbon nanosheets with enhanced surface energy storage for high-performance sodium-ion batteries

Construction of carbon and nitride double vacancy defects on ultrathin porous g-C3N4 nanosheets assisted by freeze-drying for enhanced photocatalysis

Graphitic carbon nitride based photocatalysts have been found extensive application in the degradation of antibiotics and organic pollutants. However, the insufficient of surface active sites and the low efficiency of photogenerated charge carriers separation hinder the development. Herein, ultrathin porous polymer carbon nitride nanosheets (PCNS-F) with carbon and nitride double vacancy defects were successfully fabricated. The facile freeze-drying step, following solvent-thermal treatment and preceding the thermal etching process, stands as a critical step for triggering vacancy generation and adjusting the carbon/nitride ratio. The optimized PCNS-F photocatalyst exhibits an ultrathin structure featuring a substantial abundance of defects in a porous state, resulting in exceptional structural characteristics (183.3 m² g-1, 0.84 cm³ g-1). Surface defect sites increase, and the efficient separation and transfer of photo-generated charge carriers are promoted with the introduction of a suitable vacancy density. PCNS-F demonstrated outstanding photocatalytic degradation performances for tetracycline (81.7 %) and methylene blue (97.7 %) under visible light irradiation for 2 h, which are 10 and 7.2 times higher than those of bulk g-C3N4. The active species of ∙O2- was confirmed to play a major role in the photodegradation process. This work provides a mild approach for engineering carbon and nitride double vacancy defects on g-C3N4 nanosheets, accompanied by tuning carbon/nitride ratio, to effectively eliminate pollutants and cleanse the environment.’

Schottky Junction Enhanced Photosynthesis of Hydrogen Peroxide by Ultrathin Porous Carbon Nitride Supported Ni Nanoparticles.

Artificial photosynthesis for high-value hydrogen peroxide (H2O2) through a two-electron reduction reaction is a green and sustainable strategy. However, the development of highly active H2O2 photocatalysts is impeded by severe carrier recombination, ineffective active sites, and low surface reaction efficiency. We developed a dual optimization strategy to load dense Ni nanoparticles onto ultrathin porous graphitic carbon nitride (Ni-UPGCN). In the absence and presence of sacrificial agents, Ni-UPGCN achieved H2O2 production rates of 169 and 4116 μmol g-1 h-1 with AQY (apparent quantum efficiency) at 420 nm of 3.14% and 17.71%. Forming a Schottky junction, the surface-modified Ni nanoparticles broaden the light absorption boundary and facilitate charge separation, which act as active sites, promoting O2 adsorption and reducing the formation energy of *OOH (reaction intermediate). This results in a substantial improvement in both H2O2 generation activity and selectivity. The Schottky junction of dual modulation strategy provides novel insights into the advancement of highly effective photocatalytic agents for the photosynthesis of H2O2.

0D/2D dual Fenton α-Fe2O3/Fe-doped g-C3N4 photocatalyst and the synergistic photo-Fenton catalytic mechanism insight

A novel dual Photo-Fenton photocatalyst Fe2O3–Fe–CN with excellent Fe(III)/Fe(II) conversion efficiency and trace metal ion leaching rate has been fabricated by in-situ deposition of α-Fe2O3 quantum dots on ultrathin porous Fe-doped carbon nitride (Fe–CN) nanosheets. The iron species in Fe–CN and α-Fe2O3 QDs constitute a mutually reinforcing dual Photo-Fenton effect. The 4% Fe2O3–Fe–CN showed superior performance with kobs values 8.60 and 4.80 folders greater than pure CN and Fe–CN, respectively. The synergistic effect between α-Fe2O3 QDs and the ultrathin porous structure of Fe–CN is the primary reason for the outstanding catalytic performance exhibited by α-Fe2O3/Fe–CN. On one hand, the ultrathin porous structure of Fe–CN promotes the rapid transfer of photogenerated electrons. On the other hand, the efficient photogenerated charge separation at the α-Fe2O3/Fe–CN interface enables more photogenerated electrons to participate in the Fe3+/Fe2+ conversion and H2O2 activation. The trapping experiments demonstrate that •OH and •O2− are the primary active species in TC degradation. This work presents novel insights into the design of efficient heterogeneous Fenton catalysts for practical applications.

Efficient and robust ultrathin porous carbon encapsulated Ni–Sn intermetallic compounds derived from metal–organic frameworks for in-situ aqueous phase deoxygenation of fatty acid methyl esters

Deoxygenation of fatty acid esters in aqueous phase using in-situ generated H2 has emerged as a promising approach to producing sustainable diesel-like hydrocarbons. In this study, we employed a solvothermal method to synthesize novel Ni–Sn metal–organic frameworks (MOFs) with a homogeneous distribution of Ni and Sn elements. Subsequently, various Ni–Sn intermetallic compounds (IMCs) encapsulated with a porous carbon layer (<3 nm) (Ni–Sn IMC@C) were prepared through the facile pyrolysis of metal–organic frameworks under a controlled N2 atmosphere. Applying methyl palmitate as model reactant and methanol as hydrogen donor, Ni3Sn2 IMC@C gives approximately 100% conversion and 93% yield towards n-C15 and n-C16 alkanes at 330 °C, without significant deactivation during the recycling for five times. The deoxygenation pathway is dominated by decarbonylation (DeCO) on Ni–Sn IMCs. In Ni–Sn IMCs, the oxophilic nature of Sn, along with its charge transfer with Ni, enhances the adsorption of an η2(C, O)-aldehyde configuration. The strategic isolation of adjacent Ni by Sn effectively inhibits methanation and C–C bond hydrolysis, reducing H2 consumption and increasing carbon yield. Moreover, the ultrathin porous carbon encapsulation not only prevents the loss and sintering of Ni3Sn2 IMC under harsh hydrothermal condition but also mitigates mass transfer limitation. Surface oxidation of Ni3Sn2 IMC, particularly the formation of SnO2, is detrimental to deoxygenation. Additionally, Ni3Sn2 IMC@C exhibits high hydrocarbon yields (>89.6%) in in-situ aqueous phase deoxygenation of methyl laurate, methyl stearate and methyl oleate. These findings highlight the remarkable potential of MOF-derived catalysts for hydrothermal deoxygenation.

Exploring the Remarkably High Photocatalytic Efficiency of Ultra-Thin Porous Graphitic Carbon Nitride Nanosheets.

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst used for visible-driven hydrogen production, CO2 reduction, and organic pollutant degradation. In addition to the most attractive feature of visible photoactivity, its other benefits include thermal and photochemical stability, cost-effectiveness, and simple and easy-scale-up synthesis. However, its performance is still limited due to its low absorption at longer wavelengths in the visible range, and high charge recombination. In addition, the exfoliated nanosheets easily aggregate, causing the reduction in specific surface area, and thus its photoactivity. Herein, we propose the use of ultra-thin porous g-C3N4 nanosheets to overcome these limitations and improve its photocatalytic performance. Through the optimization of a novel multi-step synthetic protocol, based on an initial thermal treatment, the use of nitric acid (HNO3), and an ultrasonication step, we were able to obtain very thin and well-tuned material that yielded exceptional photodegradation performance of methyl orange (MO) under visible light irradiation, without the need for any co-catalyst. About 96% of MO was degraded in as short as 30 min, achieving a normalized apparent reaction rate constant (k) of 1.1 × 10-2 min-1mg-1. This represents the highest k value ever reported using C3N4-based photocatalysts for MO degradation, based on our thorough literature search. Ultrasonication in acid not only prevents agglomeration of g-C3N4 nanosheets but also tunes pore size distribution and plays a key role in this achievement. We also studied their performance in a photocatalytic hydrogen evolution reaction (HER), achieving a production of 1842 µmol h-1 g-1. Through a profound analysis of all the samples' structure, morphology, and optical properties, we provide physical insight into the improved performance of our optimized porous g-C3N4 sample for both photocatalytic reactions. This research may serve as a guide for improving the photocatalytic activity of porous two-dimensional (2D) semiconductors under visible light irradiation.

2D metal–organic framework derived ultra-thin nitrogen-doped oxygen rich porous carbon nanosheets for zinc-ion hybrid supercapacitors

2D MOF derived ultra-thin carbon nanosheets with high reactivity, super-hydrophilicity and hierarchical porosity are prepared. The corresponding Zn-ion hybrid supercapacitor delivers exceptional energy storage capability with long cycling stability.

Carbon nanosheet with controlled porous and disorganized structures as high-rate anode for high-energy Na-ion hybrid capacitors

Although sodium-ion capacitors (SICs) hold great application potential in the areas where energy and power output are both highly required, they still encounter the challenge to design suitable anode materials with quick dynamics to provide high power output. In present work, a ultra-thin porous carbon nanosheet (PCS) combing the structure advantages of soft carbon (ordered nature) and hard carbon (amorphous nature) was successfully designed, which facilitates the charge transport and Na+ migration and thus guarantees the high-rate capacity and long cycle life of PCS electrodes. When tested as anode for sodium-ion batteries (SIBs), the PCS can exhibit an impressive sodium storage performance, including an excellent specific capacity of 302 mAhg−1, a high-rate capacity and a superior cycling stability (85 % capacity retention after 500 cycles at 1C). Furthermore, SICs constructed by PCS can provide a maximum energy density of 158.2 Wh kg−1 and a maximum power density of 22.8 kW kg−1, together with superior cycle lifespan. The excellent electrochemical performance demonstrates that PCS is a prospective electrode material for sodium-ion storage.

Fabrication of nitrogen-doped carbon on NiCoP electrocatalyst with flower-like structure for efficient hydrogen evolution reaction in alkaline solution

The development of hydrogen evolution catalysts with low cost, high activity, and outstanding stability has become an urgent need. Herein, we reported a novel and effective strategy for the in situ growth of NiCoP nanoparticles encapsulated in ultrathin nitrogen-doped porous carbon on nickel foam (NiCoP@NC/NF). Compared with NiCoP/NF, the NiCoP@NC/NF presented a much larger electrochemically active surface area (ECSA) (1402.9 cm2 mg−1), more abundant intrinsic HER active sites and lower charge-transfer resistance, leading to superior catalytic activity. The as-prepared NiCoP@NC/NF electrode exhibited extremely low overpotential η10 (77 mV) and Tafel slope (62.1 mV dec−1) for HER in 1.0 M KOH as the electrolyte. Importantly, due to the thin nitrogen-doped carbon layer, NiCoP@NC/NF showed considerably enhanced stability under the harsh conditions of long-term reaction. Density functional theory (DFT) calculations have indicated that the nitrogen-doped carbon of NiCoP@NC/NF permitted moderate trapping of hydrogen atoms and easy desorption of the resulting H2. Such impressive HER performance of the hybrid electrocatalyst is mainly attributed to the collective effects of elemental doping engineering between NC and NiCoP, the enlarged surface area/exposed catalytic active sites, and the lower transfer resistance due to the nitrogen-doping carbon. The present work proposed a controllable and feasible strategy for synthesizing bimetallic phosphides with unique morphology and high HER performance.

Iron phthalocyanine nanodots decorated ultra-thin porous carbon nitride: A combination of photocatalysis and Fenton reaction to achieve two-channel efficient tetracycline degradation

Recent years, many scholars have been greatly intrigued by the large amounts of emerging antibiotics pollutants (such as tetracycline, penicillin, etc.) in natural water environments. Photo-Fenton oxidation, a highly advanced oxidation technique, has been seen as a promising way to effectively break down these pollutants by generating a great deal of reactive oxygen species (ROS). Herein, iron phthalocyanine nanodots (FePc)/ultra-thin porous carbon nitride (UPCN) nanocomposites were successfully prepared by thermal polymerization and calcination processes. In the system with a small amount (10 μL) of hydrogen peroxide (H2O2) and natural pH conditions, the 1%-FePc/UPCN nanocatalcatalyst had the best degradation effect, and the TC removal rate reached 89% within 20 min and 99% within 60 min. The excellent performance of the nano-composites is ascribed to the large surface area, multiple active sites, small pore size, easy excitation and fast transfers of photogenerated carriers induced by π-π bond. In addition, the improvement of the degradation of TC is also due to the synergistic effect of the photocatalytic reaction center dominated by UPCN and Fenton reaction center dominated by FePc in the system, simultaneously. In this study, a synergistic dual-reaction center catalytic system was constructed to provide new insights and strategies for the degradation of organic pollutants in natural water environments.

Regulating Li-Ion Transport through Ultrathin Molecular Membrane to Enable High-Performance All-Solid-State-Battery.

Solid-state lithium metal batteries with garnet-type electrolyte provide several advantages over conventional lithium-ion batteries, especially for safety and energy density. However, a few grand challenges such as the propagation of Li dendrites, poor interfacial contact between the solid electrolyte and the electrodes, and formation of lithium carbonate during ambient exposure over the solid-state electrolyte prevent the viability of such batteries. Herein, an ultrathin sub-nanometer porous carbon nanomembrane (CNM) is employed on the surface of solid-state electrolyte (SSE) that increases the adhesion of SSE with electrodes, prevents lithium carbonate formation over the surface, regulates the flow of Li-ions, and blocks any electronic leakage. The sub-nanometer scale pores in CNM allow rapid permeation of Li-ions across the electrode-electrolyte interface without the presence of any liquid medium. Additionally, CNM suppresses the propagation of Li dendrites by over sevenfold up to a current density of 0.7mA cm-2 and enables the cycling of all-solid-state batteries at low stack pressure of 2MPa using LiFePO4 cathode and Li metal anode. The CNM provides chemical stability to the solid electrolyte for over 4 weeks of ambient exposure with less than a 4% increase in surface impurities.

Sustainable and Scalable Synthesis of 2D Ultrathin Hierarchical Porous Carbon Nanosheets for High-Performance Supercapacitor.

2D carbon nanomaterials such as graphene, carbon nanosheets, and their derivatives, representing the emerging class of advanced multifunctional materials, have gained great research interest because of their extensive applications ranging from electrochemistry to catalysis. However, sustainable and scalable synthesis of 2D carbon nanosheets (CNs) with hierarchical architecture and irregular structure via a green and low-cost strategy remains a great challenge. Herein, prehydrolysis liquor (PHL), an industrial byproduct of the pulping industry, is first employed to synthesize CNs via a simple hydrothermal carbonization technique. After mild activation with NH4 Cl and FeCl3 , the as-prepared activated CNs (A-CN@NFe) display an ultrathin structure (≈3 nm) and a desirable specific surface area (1021 m2 g-1 ) with hierarchical porous structure, which enables it to be both electroactive materials and structural support materials in nanofibrillated cellulose/A-CN@NFe/polypyrrole (NCP) nanocomposite, and thus endowing nanocomposite with impressive capacitance properties of 2546.3 mF cm-2 at 1 mA cm-2 . Furthermore, the resultant all-solid-state symmetric supercapacitor delivers a satisfactory energy storage ability of 90.1 µWh cm-2 at 250.0 µW cm-2 . Thus, this work not only opens a new window for sustainable and scalable synthesis of CNs, but also offers a double profits strategy for energy storage and biorefinery industry.

Ultrathin porous carbon nitride with molecular structure regulation for excellent photocatalytic water splitting

Developing universal strategy for designing novel photocatalysts with precise structure regulation is a promising approach to realizing efficient hydrogen production from water splitting, while great challenges remain since fundamental understanding of the internal mechanism is required. Herein, we demonstrate the universality of asymmetry supramolecular precursor-based route to synthesize ultrathin porous carbon nitride photocatalysts by incorporating various amino acids, which promises simultaneous production and spontaneous separation of H2 and H2O2 from pure water splitting. Through detailed controlled experimental investigation together with theoretical analysis, the mechanism of improved photocatalytic performance is illustrated, which is attributed to the promoted adsorption/desorption process and charge-carrier dynamics upon the molecular structure regulation of carbon nitride photocatalysts with aldehyde functional groups.

Cyano-rich porous carbon nitride nanosheets for enhanced photocatalytic H2O2 production

The gas template method is used to introduce the cyano (-CN) group and porous thin-layer structure into g-C3N4 simultaneously. The resulting material exhibits a synergistic effect between the -CN group and porous thin-layer structure, which broadens the optical absorption range of g-C3N4 and enhances electron transfer and transformation. The rotating ring-disk electrode (RRDE) experiments demonstrate that cyano-rich porous ultrathin carbon nitride significantly improves the selectivity of 2e- oxygen reduction reaction (ORR), with the selectivity of 93% compared to the 66% of the original carbon nitride at a potential of 0.3 V versus RHE. Additionally, the H2O2 yield for the modified carbon nitride is twice than that of the original carbon nitride material (99.11 μM vs 49.79 μM). The mechanism for photocatalytic H2O2 production involves a two-step one-electron reaction. The modified catalyst is recyclable and can be used for an extended period of time. Overall, this study provides a viable method for modifying g-C3N4 to improve its photocatalytic activity and selectivity towards the 2e- ORR.

A One-Step Self-Flowering Method toward Programmable Ultrathin Porous Carbon-Based Materials for Microwave Absorption and Hydrogen Evolution.

Ultrathin 2D porous carbon-based materials offer numerous fascinating electrical, catalytic, and mechanical properties, which hold great promise in various applications. However, it remains a formidable challenge to fabricate these materials with tunable morphology and composition by a simple synthesis strategy. Here, a facile one-step self-flowering method without purification and harsh conditions is reported for large-scale fabrication of high-quality ultrathin (≈1.5nm) N-doped porous carbon nanosheets (NPC) and their composites. It is demonstrated that the layered tannic/oxamide (TA/oxamide) hybrid is spontaneously blown, exfoliated, bloomed, in situ pore-formed, and aromatized during pyrolysis to form flower-like aggregated NPC. This universal one-step self-flowering system is compatible with various precursors to construct multiscale NPC-based composites (Ru@NPC, ZnO@NPC, MoS2 @NPC, Co@NPC, rGO@NPC, etc.). Notably, the programmable architecture enables NPC-based materials with excellent multifunctional performances, such as microwave absorption and hydrogen evolution. This work provides a facile, universal, scalable, and eco-friendly avenue to fabricate functional ultrathin porous carbon-based materials with programmability.