Nanoporous Carbon Research Articles

Strategically Designed Uniform MOF-Derived Nanoporous Carbon Aerogel for Efficient Solar-Driven Desalination by Control of Hydrophilicity and Thermal Conductivity.

Desalination techniques using the photothermal effect hold significant potential for producing fresh water from saline or polluted sources due to their low energy consumption. In the case of commercialized carbon materials are related to heat loss resulting from high thermal conductivity, and metal particles still have trouble in commercialization or cost-effectiveness. This is because a photothermal desalination evaporator must simultaneously exhibit high water evaporation performance, excellent energy conversion efficiency, sufficient hydrophilicity, and low heat loss. In this work, developing an efficient in situ energy utilization technology that instant light to heat energy conversion system based on ZIF-8/agarose-derived carbon aerogels, achieved by controlling hydrophilicity, thermal conductivity, and light absorption properties is reported. The carbon aerogel demonstrates excellent performances of improved capillary force, structural stability, and cost-effectiveness. The designed carbon aerogel, with a high surface area (524 m2 g-1), adequate hydrophilicity, and low density (0.07g cm-3), is buoyant enough to float on the water. A water evaporation efficiency of 1.53kg m-2 h-1 under 1 sun and a light-to-heat conversion of 85% are achieved, along with effective salt blocking through the size-controlled uniform ZIF-8 nanoparticles and optimized composition with agarose.

NiPd Nanoparticles on Nanoporous Carbon Embedded in Graphitic Carbon Nitride for Transfer Hydrogenation and Suzuki–Miyaura Coupling Reactions

NiPd Nanoparticles on Nanoporous Carbon Embedded in Graphitic Carbon Nitride for Transfer Hydrogenation and Suzuki–Miyaura Coupling Reactions

Raman Spectroscopy Measurements Support Disorder-Driven Capacitance in Nanoporous Carbons.

Our recent study of 20 nanoporous activated carbons showed that a more disordered local carbon structure leads to enhanced capacitive performance in electrochemical double layer capacitors. Specifically, NMR spectroscopy measurements and simulations of electrolyte-soaked carbons evidenced that nanoporous carbons with smaller graphene-like domains have larger capacitances. In this study, we use Raman spectroscopy, a common probe of local structural disorder in nanoporous carbons, to test the disorder-driven capacitance theory. It is found that nanoporous carbons with broader D bands and smaller ID/IG intensity ratios exhibit higher capacitance. Most notably, the ID/IG intensity ratio probes the in-plane sizes of graphene-like domains and supports the findings from NMR that smaller graphene-like domains correlate with larger capacitances. This study supports our finding that disorder is a key metric for high capacitance in nanoporous carbons and shows that Raman spectroscopy is a powerful technique that allows rapid screening to identify nanoporous carbons with superior performance in supercapacitors.

Visible light degradation of antibiotics catalyzed by nanoporous carbon/V2O5 nanocomposite: structural, optical and electrochemical properties

In this study, nanoporous carbon (NPC) decorated V2O5 (NPC/V2O5) nanocomposite synthesized by a hydrothermal technique using biomass-derived NPC nanoflakes towards the application of berberine hydrochloride (BH) dye degradation under visible light irradiation. The prepared samples were characterized by X-ray Diffraction (XRD), Raman spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray (EDX), UV-Visible and Photoluminescence (PL) spectroscopy. Charge transfer resistance was measured by electrochemical impedance spectroscopy (EIS) and liner sweep voltammetry (LSV). XRD studies confirm the orthorhombic crystal structure of NPC/V2O5 nanocomposite. FE-SEM and TEM analysis validate their particle-like and sheet-like morphology of V2O5 and NPC respectively. Further, UV-visible DRS and PL spectra of the green synthesized NPC/V2O5 nanocomposite exhibited a low band-gap and reduced recombination rate compared to the pure counterpart which is better light-absorbing ability in the visible light region. Batch experiments represent the incorporation of NPC and V2O5 would lead to an increase the photocatalytic performance of NPC/V2O5 toward BH dye degradation. During the photocatalytic reaction, the NPC/V2O5 nanocomposite degraded rate around 97.7% against BH dye within 80 min while pure V2O5 degraded 92.5% of BH dye under same visible light irradiation time. Finally, the cyclic stability experiment exhibits the photocatalyst even stable after five consecutive tests.

Green fabrication of cost-effective and sustainable nanoporous carbons for efficient hydrogen storage and CO2/H2 separation

In this study, sustainable nanoporous carbon materials that are efficient, renewable, cost-effective and adaptable were developed. These microporous feature carbon adsorbents were synthesized utilizing a straightforward and efficient method. Plum stones are residual fruit materials that offer a financially feasible and sustainable carbon source with exceptional porosity and desirable elemental composition. The plum stones underwent carbonization and were subsequently chemically modified with polyaniline nanofibers and then subjected to chemical activation using different activating agents. This yielded sustainable nanoporous carbon with a high degree of porosity, in conjunction with doping with precious high electron density elements such as O, N and S. The sustainable nanoporous carbons that have been developed exhibits exceptional microporosity, with BET-SSA of 1705 m2 g−1 and a pore volume of 0.726 cm3 g−1, besides, the dominance of ultramicropores of 0.6 nm size. This in addition to convenient doping of oxygen, nitrogen and sulfur elements which are crucial for H2 uptake. The developed nanoporous carbon demonstrated highly promising capabilities for storing H2 molecules at cryogenic and ambient temperatures. The sustainable adsorbent achieved hydrogen storage capacities of 4.63 and 0.45 wt% at 77, 296 K, and a pressure of 40 and 80 bar, respectively. This H2 storage capacity at RT is often regarded as one of the highest reported in the literature for nanoporous adsorbents. Moreover, study investigated the separation selectivity of developed adsorbents for CO2/H2 based on uptake ratio at 30 bar and RT. The results demonstrated a significant separation selectivity reaching a value of 382.5 for the CO2/H2, which is regarded as one of the most elevated values documented in the existing literature for nanoporous carbon materials. Thus, the presented sustainable nanoporous materials have shown great promise for hydrogen storage, pre-combustion CO2 capture and H2 purification applications at ambient temperature.

Disorder Over Pore Size: Boosting Supercapacitor Efficiency.

The urgent need for efficient energy storage systems has spotlighted supercapacitors and nanostructured porous carbon materials. These materials require structural optimization to enhance their performance and lifespan, necessitating advanced design and synthesis techniques. In a recent publication, Forse and co-workers reveal that structural disorder in nanoporous carbon materials significantly enhances their capacitance performance, suggesting that optimizing structural disorder is key to developing high-energy-density supercapacitors. This study innovatively shows that structural disorder in nanoporous carbon materials significantly enhances capacitance performance, surpassing traditional factors like pore size and surface area. The investigation of multiple nanoporous carbons from a range of different suppliers showcases the generalizability of the findings. Annealing treatment further confirms that the capacitance enhancement is due to structural disorder. This discovery guides the design and synthesis of new efficient electrode materials, providing a new direction for the future development of supercapacitors.

Nanomaterial Texture-Based Machine Learning of Ciprofloxacin Adsorption on Nanoporous Carbon.

Drug substances in water bodies and groundwater have become a significant threat to the surrounding environment. This study focuses on the ability of the nanoporous carbon materials to remove ciprofloxacin from aqueous solutions under specific experimental conditions and on the development of the mathematical model that would allow describing the molecular interactions of the adsorption process and calculating the adsorption capacity of the material. Thus, based on the adsorption measurements of the 87 carbon materials, it was found that, depending on the porosity and pore size distribution, adsorption capacity values varied between 55 and 495 mg g-1. For a more detailed analysis of the effects of different carbon textures and pores characteristics, a Quantitative nano-Structure-Property Relationship (QnSPR) was developed to describe and predict the ability of a nanoporous carbon material to remove ciprofloxacin from aqueous solutions. The adsorption capacity of potential nanoporous carbon-based adsorbents for the removal of ciprofloxacin was shown to be sufficiently accurately described by a three-parameter multi-linear QnSPR equation (R2 = 0.70). This description was achieved only with parameters describing the texture of the carbon material such as specific surface area (Sdft) and pore size fractions of 1.1-1.2 nm (VN21.1-1.2) and 3.3-3.4 nm (VN23.3-3.4) for pores.

Efficient electrocatalytic urea synthesis from CO2 and nitrate over the scale-up produced FeNi alloy-decorated nanoporous carbon

Electrocatalytic urea synthesis provides a favorable strategy for conventional energy-consuming urea synthesis, but achieving large-scale catalyst synthesis with high catalytic efficiency remains challenging. Herein, we developed a simple method for the preparation of a series of FeNi-alloy-based catalysts, named FeNi@nC-T (n represents the content of nanoporous carbon as 1, 3, 5, 7 or 9 g and T = 900, 950, 1000 or 1100 °C), for highly performed urea synthesis via NO3− and CO2 co-reduction. The FeNi@7C-1000 achieved a high urea yield of 1041.33 mmol h−1 gFeNi−1 with a Faradaic efficiency of 15.56% at –1.2 V vs. RHE. Moreover, the scale-up synthesized FeNi@7C-950-S (over 140 g per batch) was achieved with its high catalytic performance and high stability maintained. Mechanism investigation illuminated that the Ni and Fe sites catalyze and stabilize the key *CO and *N intermediates and minimize the C–N coupling reaction barriers for highly efficient urea synthesis.

Impacting the Surface Chemistry of NiAu by Immobilizing on MgO/N-Rich Nanoporous Carbon Heterostructures for Boosting Catalytic Activities.

Tuning the physical and chemical interaction between metal-metal' (M-M') and metal-support is an ideal way to realize enhanced catalytic activity of metal nanoparticles (NPs). As a proof of concept, herein we report the fabrication of nickel-gold (Ni-Au) alloy nanoparticles attached to N-doped nanoporous carbon (NPC) intervened with MgO (Ni73Au27@MgO-NPC), achieved through the impregnation of metal precursors into Schiff-base network polymer (SNP) framework along with Mg(OH)2 and pyrolysis at 800 °C in N2 atmosphere. With high stability and heterogeneity, the nickel rich Ni73Au27@MgO-NPC exhibited higher catalytic activities with turnover frequencies of 29,272 h-1 (hydrogenation of p-nitrophenol), 93,843 h-1 (degradation of methyl orange), and 2,218 h-1 (epoxidation of stilbene), compared to commercial 10 wt % Pd/C. Enhanced catalytic activity is correlated to the synchronized electron density enhancement in Au, by Ni and MgO/N-rich nanoporous carbon heterostructures, as evident from detailed X-ray photoelectron spectroscopic studies.

Defective carbon-bridged Cu sites to boost oxygen reduction reaction in neutral zinc-air batteries

Novel carbon nanomaterials containing N-coordinated metal centers present an advantage in promoting the oxygen reduction reaction (ORR). Despite considerable progress, substantial challenges persist with the advancement of neutral Zinc-air batteries (ZABs), particularly in optimizing the trade-off between the catalytic activity and stability. Herein, employing nanoporous carbon impregnated with Cu(II)-phenanthroline complexes to prepare Cu-ONCs catalysts rich in Cu-Nx sites. Controllable carbon defects to capture Cu2+ enable the enrichment of metal sites on the porous carbon surface, and simultaneously effectively suppress the aggregation of active centers. The metal moieties, specifically Cu-Nx, are incorporated into the porous N-doped carbon, thereby introducing accessible active sites within the partially graphitized carbon framework. Furthermore, the abundant mesopores inside the carbon nanofibers promote the exposure of accessible active sites to substantially augment the electrochemically active electrochemically active area area. Given the unique structure and composition, Cu-ONCs show outstanding ORR activity in neutral and alkaline media, alone with negligible decay observed after 3000 cycles. Moreover, Cu-ONCs based neutral ZABs demonstrate a peak power density of 48.28 mW cm−2 and impressive rate performance. This work provides defects/vacancies insight on transition metal (TM)-based carbon support to facilitate the advancement of cutting-edge neutral ZABs.

Anomalous enhancement of humid CO2 capture by local surface bound water in polar carbon nanopores

Removal of confined space carbon dioxide (CO2) that is in low concentration and with coexisting water is necessary but challenging by physical adsorption method. To make the removal process effective, rendering the nanopore surface hydrophobic to resist water is the popular way. Instead of preventing water from occupying the nanopores, in this work, we propose to utilize the guest water for the spatially selective formation of local surface bound water and further induce the preferential CO2 capture. We observe an anomalous enhancement of CO2 capture performance under humid conditions over carbon nanopores with spatially selective polar sites. It is evidenced that the surface bound water is formed at non-CO2-selective areas of polar carbon nanopores, thus creating additional CO2 trapping sites. This work may inspire the design of environment tolerable materials for molecular separation and purification under harsh conditions.

Tailoring Pore Architecture and Heteroatom Functionality of Polymeric Waste-Derived Nanoporous Carbon for CO2 Capture Applications

Tailoring Pore Architecture and Heteroatom Functionality of Polymeric Waste-Derived Nanoporous Carbon for CO₂ Capture Applications

Nanoporous Carbon-Supported Bimetallic (Ni, Cu, and Fe)-Mo Catalysts for Partial Hydrogenation of Biodiesel.

Upgrading biodiesel or hydrogenated fatty acid methyl esters (H-FAMEs) by partial hydrogenation is a second-generation biofuel with high specific fuel characteristics, such as superior cold flow properties, higher oxidative stability, and lower hazardous gas emissions, allowing this biofuel to provide excellent fuel properties, over conventional biodiesel. This study assessed the potential of using nanoporous carbon produced from cattail leaves (CL) as an alternative catalyst support. We synthesized various catalysts including monometallic Mo/NPC, Ni/NPC, Ce/NPC, and Fe/NPC catalysts, as well as bimetallic molybdenum-based catalysts doped with nickel, copper, or iron for the partial hydrogenation of soybean biodiesel. The NPC support demonstrated a surface area (S BET) of approximately 1,323 m2g-1, which greatly increases the catalytic activity through the efficient dispersion of catalyst active sites. The partial hydrogenation reaction of soybean FAME over the MoNi/NPC catalyst obtained the highest catalytic activity with enhanced oxidation stability from 3 to 14 h, and the cloud point and pour point increased from 2 to 13 °C and -1 to 10 °C, respectively. Hence, the selection of catalysts is crucial due to their impact on the feasibility of the process and its economic viability. This article focuses on highlighting the effectiveness of a highly promising catalyst for partial hydrogenation as well as examining the variables that influence the primary reaction pathway.

Efficient Isolation of Cellulose Nanocrystals from Seaweed Waste via a Radiation Process and Their Conversion to Porous Nanocarbon for Energy Storage System.

This article presents an efficient method for isolating cellulose nanocrystals (CNcs) from seaweed waste using a combination of electron beam (E-beam) irradiation and acid hydrolysis. This approach not only reduces the chemical consumption and processing time, but also improves the crystallinity and yield of the CNcs. The isolated CNcs were then thermally annealed at 800 and 1000 °C to produce porous nanocarbon materials, which were characterized using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy to assess their structural and chemical properties. Electrochemical testing of electrical double-layer capacitors demonstrated that nanocarbon materials derived from seaweed waste-derived CNcs annealed at 1000 exhibited superior capacitance and stability. This performance is attributed to the formation of a highly ordered graphitic structure with a mesoporous architecture, which facilitates efficient ion transport and enhanced electrolyte accessibility. These findings underscore the potential of seaweed waste-derived nanocarbon as a sustainable and high-performance material for energy storage applications, offering a promising alternative to conventional carbon sources.

Computational Analysis of Permeance Prediction for Gas Separation Membrane Using Countercurrent Flow Model

Gas separation polymeric membranes have gained significant attention in various industries, including gas processing, petrochemicals, and environmental applications. Accurately predicting the permeance of these membranes is crucial for optimizing their design and performance. This paper presented a numerical prediction model for the permeance of a binary gas mixture under various process conditions, using only algebraic equations to minimize the calculation effort. The model considers input parameters such as feed and permeate flow rates, feed pressure, feed and permeate mole fraction, and membrane area. It demonstrates the behavior of permeance and selectivity in this study. The study also presented two case studies that utilize predicted selectivity to model counter-current flow and compare the results with experimental data from the literature. The first case study involves recovering helium from natural gas using an asymmetric high-flux membrane. The second case study separates air using nano-porous carbon as the membrane material. The numerical analysis successfully accurately predicted the permeance of gas separation polymeric membranes. The model accounted for variations in membrane thickness, feed composition, and operating conditions, providing valuable insights into the overall performance of the membrane system. It also allowed for the optimization of membrane design and operational parameters to enhance separation efficiency and productivity. The study showcased the effectiveness of numerical techniques in accurately predicting membrane performance. The developed model can be a valuable tool for membrane designers and engineers, enabling them to optimize the design and operation of gas separation systems.

Decafluorinated and Perfluorinated Warped Nanographenes: Synthesis, Structural Analysis, and Properties.

Fluorination is a useful approach for tailoring the physicochemical properties of nanocarbon materials. However, owing to the violent reactivity of fluorination, achieving edge-perfluorination of nanographene while maintaining its original π-conjugated structure is challenging. Instead of using traditional fluorination, here, we employed a bottom-up strategy involving fluorine preinstallation and synthesized decafluorinated and perfluorinated warped nanographenes (DFWNG and PFWNG, respectively) through a 10-fold Suzuki-Miyaura coupling followed by a harsh Scholl reaction, whereby precisely edge-perfluorinated nanographene with an intact π-conjugated structure was achieved for the first time. X-ray crystallography confirmed the intact π-conjugated structure and more twisted saddle-shaped geometry of PFWNG compared to that of DFWNG. Dynamic study revealed that the 26-ring carbon framework of PFWNG is less flexible than that of DFWNG and the pristine WNG, enabling chirality resolution of PFWNG and facilitating the achievement of CD spectra at -10 °C. The edge-perfluorination of PFWNG resulted in improved solubility, lower lowest unoccupied molecular orbital, and a surface electrostatic potentials/dipole moment direction opposite those of the pristine WNG. Likely owing to its intact π-conjugated structure, PFWNG exhibits comparable electron mobility with well-known PC61BM. Furthermore, perfluorination improves thermal stability and hydrophobicity, making PFWNG suitable for use as a thermostable/hydrophobic n-type semiconductor material. In the future, this fluorination strategy can be used to synthesize other perfluorinated nanocarbon materials, such as perfluorinated graphene nanoribbons and porous nanocarbon.

Synthesis of nanoporous carbon from Ulva lactuca activated by eggshell for CO2 capture: a novel approach to waste valorization.

Facing the daunting challenge of climate change, driven by escalating greenhouse gas concentrations, our research introduces an innovative solution for CO2 capture. We explore a novel nanoporous carbon derived from Ulva lactuca, activated with eggshell waste, spotlighting waste valorization in mitigating atmospheric CO2. Through a systematic methodology encompassing variable carbonization temperatures (700-900°C) and nitrogen flow rates (2-4ml/min), complemented by a suite of characterization techniques, we unveil the synthesis of this pioneering adsorbent. Our study not only presents a novel, sustainable pathway for CO2 capture but also demonstrates superior performance, particularly with the NC800-4 sample, achieving a CO2 capture capacity of 1.40mmol/g at 30°C, alongside demonstrating consistent adsorption efficiency over four successive adsorption/desorption cycles. This breakthrough underscores the potential of leveraging waste for environmental remediation, offering a dual solution to waste management and carbon capture, utilization, and storage (CCUS) applications.

Monte Carlo simulation of an ammonia adsorption refrigeration system based on calcium chloride impregnated nanoporous carbon.

We use Monte Carlo simulations to investigate the effect of incorporating calcium chloride salt into nanoporous carbon on the performance of an ammonia-carbon adsorption refrigeration system. Simulations of ideal carbon slit-pores with pore sizes of 1, 2, and 3nm, each containing calcium chloride with ion densities of 0.0, 0.25, and 0.5nm-3, were carried out at temperatures between 0 and 30 °C and ammonia pressures up to 15.0 bar. The results reveal that ideal 1nm pores are able to achieve a good refrigeration performance using waste heat below 100 °C to drive the process, but adding salt to these pores increases the waste heat temperature required beyond 100 °C. However, ideal 2nm pores require the addition of 0.25nm-3 salt to achieve a similar performance, while the 3nm pores were unable to achieve a satisfactory refrigeration performance. Considering that real nanoporous carbons usually feature a variety of specific adsorption sites and non-ideal geometries that should have a similar impact to adding salt, these results indicate that nanoporous carbons with pores in the range of 1-2nm are likely to hold the most promise for adsorption refrigeration applications and that the addition of salt may not always be helpful.

Enhancing chemical heat storage performance of nanocarbon porous particle based MgO/Mg(OH)2 composite by calcination method

The application of MgO/Mg(OH)2 in heat storage technology has been limited due to slow hydration rate and easy agglomeration. In this paper, nanoporous carbon particle (NCP) as a carrier was used to prepare NCP/MgO chemical heat storage composite materials by impregnation and calcination methods, respectively. The microstructure characterization, hydration reaction, and simultaneous thermogravimetric analysis experiments were carried out on the prepared composite materials. The results showed that the internal distribution of MgO in the composite material prepared by calcination method was more uniform, and the particle size of MgO was smaller. Under the conditions of 110 ℃ hydration temperature and 57.8 kPa water vapor partial pressure, the hydration conversion ratio of the composite material prepared by calcination method after 120 min of hydration conversion ratio reached 93 %, which was 17.7 % higher than that of the impregnated composite material and 50 % higher than that of pure MgO. Under the comprehensive influence of specific surface area, pore structure, and active component particle size, compared with pure materials and impregnated composite materials, the dehydration rate of the composite material prepared by calcination method at 300 ℃ was twice that of impregnated method and 6 times that of pure MgO, and the heat storage density reached 1039kJ/kg. After 10 cycles, the heat storage density still maintained an initial state of 95.8 %. Compared with pure materials and impregnated composite materials, NCP/MgO composite materials prepared by calcination method had better heat storage performance and higher cyclic stability.

Molecular simulation using transfer-learned potentials for the disordered nanoscale structure of nitrogen-doped nanoporous carbons

Machine learning (ML)-based molecular dynamics (MD) simulations of the formation of a class of N-doped nanoporous carbons are performed to assess their disordered partially graphitized nanoscale structure. The study is motivated by the effectiveness of so-called nitrogen assembly carbons (NACs) for catalysis applications. Benchmark simulations for pure-C disordered graphitic systems reveal the importance of reliably capturing the vdW component of the potentials in order to accurately describe the tendency for layering of disordered graphene-like sheets. In our modeling, this is achieved by a transfer learning strategy incorporating features of the energetics from the optB88-vdW DFT functional into potentials initially trained with a less expensive functional, thereby providing a superior description of the pure-C systems. Generation from MD simulations of realistic partially graphitized structures is significantly more challenging for N-doped versus for pure C systems. However, such structures are achieved by a tailored MD simulation protocol mimicking the experimental synthesis process and in particular incorporating an annealing and subsequent quenching stages. Simulated PXRD patterns effectively reproduce the features of experimental observations for NACs, including the appearance of a prominent but broad (002) peak at around 25∘, and the development of another weaker feature associated with in-layer ordering of mixed C-N graphene-like sheets.