Hybrid Carbon Research Articles

Metal-Organic Framework-Derived Mesoporous B-Doped CoO/Co@N-Doped Carbon Hybrid 3D Heterostructured Interfaces with Modulated Cobalt Oxidation States for Alkaline Water Splitting.

Heteroatom-doped transition metal-oxides of high oxygen evolution reaction (OER) activities interfaced with metals of low hydrogen adsorption energy barrier for efficient hydrogen evolution reaction (HER) when uniformly embedded in a conductive nitrogen-doped carbon (NC) matrix, can mitigate the low-conductivity and high-agglomeration of metal-nanoparticles in carbon matrix and enhances their bifunctional activities. Thus, a 3D mesoporous heterostructure of boron (B)-doped cobalt-oxide/cobalt-metal nanohybrids embedded in NC and grown on a Ni foam substrate (B-CoO/Co@NC/NF) is developed as a binder-free bifunctional electrocatalyst for alkaline water-splitting via a post-synthetic modification of the metal-organic framework and subsequent annealing in different Ar/H2 gas ratios. B-CoO/Co@NC/NF prepared using 10% H2 gas (B-CoO/Co@NC/NF [10% H2 ]) shows the lowest HER overpotential (196mV) and B-CoO/Co@NC/NF (Ar), developed in Ar, shows an OER overpotential of 307mV at 10mA cm-2 with excellent long-term durability for 100h. The best anode and cathode electrocatalyst-based electrolyzer (B-CoO/Co@NC/NF (Ar)(+)//B-CoO/Co@NC/NF (10% H2 )(-)) generates a current density of 10mA cm-2 with only 1.62V with long-term stability. Further, density functional theory investigations demonstrate the effect of B-doping on electronic structure and reaction mechanism of the electrocatalysts for optimal interaction with reaction intermediates for efficient alkaline water-splitting which corroborates the experimental results.

Selective Delivery of Tofacitinib Citrate to Hair Follicles Using Lipid-Coated Calcium Carbonate Nanocarrier Controls Chemotherapy-Induced Alopecia Areata.

Chemotherapy-induced alopecia (CIA) is one of the common side effects in cancer treatment. The psychological distress caused by hair loss may cause patients to discontinue chemotherapy, affecting the efficacy of the treatment. The JAK inhibitor, Tofacitinib citrate (TFC), showed huge potential in therapeutic applications for treating baldness, but the systemic adverse effects of oral administration and low absorption rate at the target site limited its widespread application in alopecia. To overcome these problems, we designed phospholipid-calcium carbonate hybrid nanoparticles (PL/ACC NPs) for a topical application to target deliver TFC. The results proved that PL/ACC-TFC NPs showed excellent pH sensitivity and transdermal penetration in vitro. PL/ACC NPs offered an efficient follicular targeting approach to deliver TFC in a Cyclophosphamide (CYP)-induced alopecia areata mouse model. Compared to the topical application of TFC solution, PL/ACC-TFC NPs significantly inhibited apoptosis of mouse hair follicles and accelerated hair growth. These findings support that PL/ACC-TFC NPs has the potential for topical application in preventing and mitigating CYP-induced Alopecia areata.

Emission reduction with hybrid mechanisms in civil aviation: An evolutionary game approach

With the rapid growth of the aviation industry, the issue of carbon emissions has become a substantial challenge for governments and airlines. This paper proposes a hybrid carbon emission reduction mechanism, including major airlines in the emission trading systems and implementing carbon tax for small and medium-sized airlines. First, a tripartite evolutionary game model is constructed to study strategic behaviors. Second, four scenarios of evolutionarily stable strategies (ESSs) are analyzed. Finally, the influencing parameters of players’ strategy choices are analyzed through simulations. The results show that: 1) the steady development scenarios (1, 1, 1) can be reached under the appropriate conditions; 2) the parameters such as carbon allowances and carbon tax prices significantly influence the evolutionary trend of stakeholders’ dynamic choices; 3) the implementation of a hybrid mechanism by the government could facilitate the choice of low carbon operation strategies for both types of airlines. Accordingly, a series of policy recommendations are proposed to promote carbon emission reduction in civil aviation. This study combines evolutionary game and scenario analysis methods in an attempt to provide a new perspective on carbon emission reduction governance, thereby promoting the effective development of carbon emission reduction in civil aviation in the future.

Architecture and active motif engineering of N–CoS2@C yolk–shell nanoreactor for boosted tetracycline removal via peroxymonosulfate activation: Performance, mechanism and destruction pathways

Rational construction of yolk-shell architecture with regulated binding configuration is crucially important but challengeable for antibiotic degradation via peroxymonosulfate (PMS) activation. In this study, we report the utilization of yolk-shell hollow architecture consisted of nitrogen-doped cobalt pyrite integrated carbon spheres (N–CoS2@C) as PMS activator to boost tetracycline hydrochloride (TCH) degradation. The creation of yolk-shell hollow structure and nitrogen-regulated active site engineering of CoS2 endow the resulted N–CoS2@C nanoreactor with high activity for PMS activating toward TCH degradation. Intriguingly, the N–CoS2@C nanoreactor exhibits an optimal degradation performance with a rate constant of 0.194 min−1 toward TCH via PMS activation. The 1O2 and SO4•− species are demonstrated as the dominant active substances for TCH degradation through quenching experiments and electron spin resonance characterization. The possible degradation mechanism, intermediates and degradation pathways for TCH removal over the N–CoS2@C/PMS nanoreactor are unveiled. Graphitic N, sp2−hybrid carbon, oxygenated group (C–OH) and Co species are verified as the possible catalytic sites of N–CoS2@C for PMS activation toward TCH removal. This study offers a unique strategy to engineer sulfides as highly efficient and promising PMS activators for antibiotic degradation.

Roll-to-roll solvent-free manufactured electrodes for fast-charging batteries

Roll-to-roll solvent-free manufactured electrodes for fast-charging batteries

Solid Carbon Products of Isobutane Decomposition in Laser Plasma

In this work, the properties of carbon films fabricated upon the action of laser plasma on the simple gaseous hydrocarbons have been studied. The change in the properties of these films caused by subsequent thermal or laser treatment has been investigated. Carbon films deposited on a cold substrate have a complex nature, which is similar to the nature of tholins. These films contain carbon atoms in the sp2- and sp3-hybrid states in proportional amounts, as well as various structural fragments containing hydrogen and oxygen. Thermal annealing of carbon films leads to a decrease in the concentration of hydrogen and oxygen-containing structures, unification of the structure based on carbon atoms in sp3 hybridization and formation of a so-called diamond-like structure. It was shown that carbon films are formed by spherical particles with an average diameter of 7–8 nm. Laser annealing and fabrication of a film with direct constant laser exposure leads to formation of a graphene-like structure meaning sp2 hybridization of carbon.

Pyrolyzed iron–nitrogen–carbon hybrids for efficient contaminant decomposition via periodate activation: Active site and degradation mechanism

The practical application of periodate-based advanced oxidation technologies (PI-AOTs) for wastewater treatment requires efficient and cost-effective activators. Pyrolyzed Fe–N/C materials are potential candidates, however, their actual active sites and activation mechanisms are yet to be fully understood. Herein, a series of Fe–N/C samples (denoted as Fe@NC-X) with differing structures and iron components were delicately synthesized. Experimental studies on the structure–activity relationship and density functional theory (DFT) computations revealed that Fe–Nx species serve as the dominant active site for periodate activation, while the inactive iron-based particles (i.e., Fe0 and Fe3C) optimized the binding affinity of surrounding carbon layers with periodate, resulting in enhanced activity. In-depth exploration of the oxidative mechanism revealed that Fe@NC-X activated periodate through an electron transfer regime. Our results also showed that the optimal Fe@NC-0.2/periodate system was highly effective in catalyzing the oxidation of 4-CP, outperforming many reported activators. These findings provide an indispensable foundation for the rational development of advanced Fe–N/C activators and offer vital insights into the mechanism underlying pollutant destruction through PI-AOTs.

Activation of waste tire pyrolysis carbon black by simulated fuel gas

Waste tires are also known as “black pollution”, and pose significant risks to human health and ecosystems. The pyrolysis process can recover valuable products such as natural gas, oil, and pyrolysis carbon black (CBp), with CBp being the most important one. However, CBp from waste tires has a high degree of particle aggregation and low oil absorption value, making it difficult to further utilize. In this work, we propose a novel method to activate CBp by simulated fuel gas, which fully utilizes exhaust gas resources and enables the reuse of resources. The simulated fuel gas, composed of a mixture of N2 and CO2, was used to investigate the effects of activation temperature (700–1000 °C), activation time (2–5 h), flow rates (30–50 mL·min−1), and the content of CO2 in the simulated fuel gas (10%-90% (volume)) on increasing the specific surface area. The samples were analyzed using XRD, SEM, N2 adsorption/desorption, and Raman shift. The results indicate that the hybrid atoms and carbon atoms in CBp can absorb enough energy to open the closed pores, allowing the activator to fully react with CBp. This work demonstrates a feasible approach to improve the high value-added utilization of cracked carbon black.

Flexural behavior of carbon/glass inter-ply hybrid FRP composites under elevated temperature environments

Abstract In this research work, the three-point flexural performance of carbon and/or glass inter-ply hybrid epoxy composite by altering the hybrid ratio and stacking position was studied. These materials were tested at various temperatures (30 °C, 50 °C, 70 °C and 110 °C). The test results of hybrid composites results were compared with neat glass/epoxy and carbon/epoxy composites. The stacking position of carbon fibers in hybrid composite plays a vital role while doing a flexural test. Incorporation of two stiffer carbon fibers in glass/epoxy composite i.e., C2G3 and C1G3C1, resulted in a remarkable increment in the case of flexural strength. All composites exhibited ductile behavior at 110 °C. The fractured surfaces revealed the failure mechanism of the composites.

Effect of volume ratio and hybrid mode on low-velocity impact properties of unidirectional flax/carbon fiber hybrid reinforced polymer composites

Hybrid fiber reinforced polymer composites have attracted widespread attention because they can fully utilize the advantages of two different types of fibers. To produce fiber reinforced polymer composites with excellent impact properties, unidirectional carbon/flax hybrid fiber reinforced polymer composite (HFRP) plates were developed using a filament-winding technique. The effects of the carbon fiber content and hybrid mode (a carbon–flax–carbon or flax–carbon–flax structure) on the impact properties and residual compressive properties of the HFRP plates were studied. Acoustic emission tests were performed to characterize the damage during impact, and the K-means cluster analysis method was used to investigate the HFRP damage development during post-impact compression. The test results indicate the higher carbon fiber contents enhanced their specific energy absorption (SEA), as the impact-induced brittle fracturing of the carbon-fiber layers was more severe. The hybrid mode and impact energy level critically influenced the HFRP SEA behavior. The HFRP plate with flax skin exhibited high SEA at a low impact energy, whereas that with carbon fiber skin exhibited high SEA at a high impact energy along with perforation. A more severe extension of the damage caused by the original impact occurs in the impacted HFRP under a compressive load.

Portable smartphone platform based on tunable chiral fluorescent carbon dots for visual detection of L-Asp and L-Lys

Amino acids are involved in many physiological processes such as neurotransmitter transmission, protein synthesis and immune regulation, which play an indispensable role in life science. However, accurate monitoring of amino acid metabolism still faces a huge challenging due the lack of robust detection approaches. Herein, three-color emission tunable fluorescent carbon dots (CDs) were successfully synthesized by a simple one-step solvothermal treatment using classical precursors. These multi-color CDs exhibited a bright and steady luminescence shifting from blue to red under UV–vis light excitation. Detailed characterization by various precision instruments demonstrated that the unique structure of the prepared polychromatic emission CDs was composed of sp2 hybrid carbon nucleus and part of sp3 hybrid carbon atom. These CDs displayed low cytotoxicity and excellent multi-color cell imaging ability at single wavelength excitation. Moreover, the chiral structure on the surface of the red emissive carbon dots (R-CDs) was well preserved at temperatures far below the melting point of the chiral precursor. Especially, the chiral red emissive CDs (R-L-CDs) as sensitive and selective fluorescent probe could quickly identify L-Aspartic acid (L-Asp) and L-Lysine (L-Lys) in water and biological samples. Additionally, smart phone color recognizer application could realize more accurate visual detection to compensate the defect that the naked eye did not distinguish subtle colors. Therefore, the multi-excitation mode could be effectively shield background interference from complex samples by introducing a self-calibrating reference signal, ensuring accurate and reliable quantitative information, endowing R-L-CDs as a biosensor with far-reaching prospects for further application by binding target analytes.

Thermal stratification effect on gravity driven transport of hybrid CNTs down a stretched surface through porous medium

The purpose of the current article is to explore the impact of thermal stratification and medium porosity on gravity-coerced transport of hybrid carbon nanotubes down an upright extending sheet inspired by a constant applied magnetic field along with heat transfer investigation in existence of thermal radiation, viscous dispersal, and joule heating effect. Rectangular coordinates are chosen for the mathematical interpretation of the governing flow problem. Homothetic analysis is employed for the sake of simplification process. The reduced system of coupled nonlinear differential equations is dealt numerically by dint of computational software MATLAB inbuilt routine function Bvp4c. The numerical investigation is carried out for the distinct scenarios namely, (i) Presence of favorable buoyancy force, (ii) Case of purely forced convection and (iii) Presence of opposing buoyancy force. Significant Findings: The key findings include that the presence of hybrid carbon nanotubes and medium porosity contributes significantly to upsurging surface shear stress magnitude whereas, external magnetic field and velocity slip effects in an altered manner. The present study may be a benchmark in study of fueling process in space vehicles and space technology.

Synthesis of Non-Aromatic Pyrroles Based on the Reaction of Carbonyl Derivatives of Acetylene with 3,3-Diaminoacrylonitriles.

The reaction of 3,3-diaminoacrylonitriles with DMAD and 1,2-dibenzoylacetylene was studied. It is shown that the direction of the reaction depends on the structure both of acetylene and of diaminoacrylonitrile. In the reaction of DMAD with acrylonitriles bearing a monosubstituted amidine group, 1-substituted 5-amino-2-oxo-pyrrole-3(2H)ylidenes are formed. On the other hand, a similar reaction of acrylonitriles containing the N,N-dialkylamidine group affords 1-NH-5-aminopyrroles. In both cases, pyrroles containing two exocyclic double bonds are formed in high yields. A radically different type of pyrroles containing one exocyclic C=C bond and sp3 hybrid carbon in the cycle is formed in reactions of 3,3-diaminoacrylonitriles with 1,2-diaroylacetylenes. As in reactions with DMAD, the interaction of 3,3-diaminoacrylonitriles with 1,2-dibenzoylacetylene can lead, depending on the structure of the amidine fragment, both to NH- and 1-substituted pyrroles. The formation of the obtained pyrrole derivatives is explained by the proposed mechanisms of the studied reactions.

Excellent and effective interfacial transition layer with an organic/inorganic hybrid carbon nanotube network structure for basalt fiber reinforced high-performance thermoplastic composites

Basalt fiber reinforced high-performance thermoplastic (BFRHTP) composites are promising materials for application in military, aerospace, chemical, automobile, and other high-tech industries. However, their mechanical properties are still largely limited by poor interfacial properties because of the smooth, inert, and low-energy surface of BF. In this study, an organic/inorganic hybrid sizing agent was used for BF surface modification to construct an appropriate modulus transition layer for the interface with a combination of soft and rigid phases. Organic poly(ether nitrile) (PEN) and inorganic carboxylic multi-walled carbon nanotubes (MWCNT-COOH) in hybrid sizing agents (PEN/CNT) were respectively used as soft and rigid phases to design the interfacial structure. The tensile strength, flexural strength, interlaminar and interfacial shear strength of the basalt fiber reinforced poly(phthalazinone ether nitrile ketone) composites were increased by 60, 33, 62, and 144%, respectively. This approach provides a simple, green, and promising strategy for enhancing the interfacial properties of BFRHTP composites.

Studies on bond relationship between energy of activation and catalytic activity of azomethine polymer framework enveloped over mesquite carbon hybrid composite electrodes for energy production applications

Studies on bond relationship between energy of activation and catalytic activity of azomethine polymer framework enveloped over mesquite carbon hybrid composite electrodes for energy production applications

Rational design of hierarchically nanostructured NiTe@CoxSy composites for hybrid supercapacitors with impressive rate capability and robust cycling durableness

The hierarchically nanostructured NiTe@CoxSy composites are constructed on a foamed nickel substrate by a two-step electrode preparation process. Structural characterization shows the dense growing of CoxSy nanosheets around NiTe nanorods forms a hierarchical nanostructure which possesses synergetic effects from both compositional and structural complementarity, more pathways for ion/electrolyte transport, richer redox active sites, and better conductivity. Thanks to the rational design of this hierarchical structure, NiTe@CoxSy delivers a high areal capacitance of 7.7F cm−2 at 3 mA cm−2 and achieves the improved capacitance retention of 97.9% after 10,000 cycles. Of particular importance is the successful fabrication of NiTe@CoxSy//activated carbon hybrid supercapacitors. This hybrid device has a wide operating voltage window, high areal energy density of 0.48 mWh cm−2 at 2.55 mW cm−2, impressive rate capability of 62.3% even after a 20-fold increase of the current density, and a 115.1% of initial capacitance retention after 15,000 cycles. Meanwhile, two tandem such hybrid devices can easily drive a pair of mini fans or light up a heart-like pattern assembled by 10 red LEDs. These experimental results not only demonstrate that the hierarchically nanostructured NiTe@CoxSy composites can serve as a prospective candidate electrode; but also develop a novel strategy about how to achieve high-performance stockpile equipment by rationale designing a desirable nanostructures.

Reaction kinetics for hydrothermal liquefaction of Cu-impregnated water hyacinth to bio-oil with product characterization

Hydrothermal liquefaction is a promising technology for the conversion of biomass to bio-oil and gaseous fuels. In the present work, isothermal hydrothermal liquefaction experiments of Cu-impregnated water hyacinth were conducted at 280 °C and investigated the effect of reaction time (10 min to 45 min) on bio-oil, carbon hybrids, aqueous products, and gas yields. A short residence time of 15 min was found to be optimum to achieve a maximum total bio-oil yield of 34.82% and analyzed by GC-MS and NMR for identification of compounds. Solid residues were analyzed by FESEM, XPS, XRD, and BET for morphological study, Cu loading, and its transition in the hydrothermal environment. Based on experimental data, reaction kinetics was developed and compared for hydrothermal liquefaction of Cu-impregnated water hyacinth with raw water hyacinth to predict the influence of Cu metal on reaction rate constants during hydrothermal liquefaction. From the kinetic modeling, it was found that the presence of Cu promoted the biomass conversion to bio-oil with light oil to heavy oil ((k4) 0.24404 min−1) conversion being the dominating reaction path. In contrast to catalytic degradation, the light oil conversion to aqueous phase components with a rate constant of 0.26323 min−1 is the most prevailing step for non-catalytic hydrothermal liquefaction.

Impact of Proton Irradiation on Medium Density Polyethylene/Carbon Nanocomposites for Space Shielding Applications.

The development of novel materials with improved radiation shielding capability is a fundamental step towards the optimization of passive radiation countermeasures. Polyethylene (PE) nanocomposites filled with carbon nanotubes (CNT) or graphene nanoplatelets (GNP) can be a good compromise for maintaining the radiation shielding properties of the hydrogen-rich polymer while endowing the material with multifunctional properties. In this work, nanocomposite materials based on medium-density polyethylene (MDPE) loaded with different amounts of multi-walled carbon nanotubes (MWCNT), GNPs, and hybrid MWCNT/GNP nanofillers were fabricated, and their properties were examined before and after proton exposure. The effects of irradiation were evaluated in terms of modifications in the chemical and physical structure, wettability, and surface morphology of the nanocomposites. The aim of this work was to define and compare the MDPE-based nanocomposite behavior under proton irradiation in order to establish the best system for applications as space shielding materials.

Salt–template assisted fabrication of Co3O4 nanodots anchored into 2D N–doped carbon nanosheets as an advanced anode for lithium–ion batteries

The design and exploitation of advanced transition metal oxides (TMO)/carbon hybrid anodes remain significant but challenging for the evolution of lithium–ion batteries (LIBs). In this work, Co3O4 nanodots anchored into 2D N-doped carbon nanosheets (Co3O4 NDs/NCN) hybrid is successfully fabricated by a facile salt-template assisted pyrolysis strategy using glucose, Co(NO3)2·6H2O and NaCl salt template as reaction precursors. The morphology, structure and composition of the resultant Co3O4 NDs/NCN hybrid are systematically investigated, and the effect of salt template on the preparation of products is also deeply explored. It is surprisingly found that the introduction of NaCl template promotes the formation of Co3O4, which is different from what has been reported previously. In addition, the added NaCl template can be used to regulate the microstructure of Co3O4 NDs/NCN hybrid, which displays unique micromorphology (Co3O4 NDs anchored into 2D NCN), successful N doping in carbon matrix, Co-N-C bond between two components and much increased specific surface area. As a result, this hybrid shows excellent lithium storage performance when used as the anode for LIBs, which can be comparable to those previously reported Co3O4/C hybrid anodes. Clearly, this work offers a good reference for the construction of low-cost and high-performance TMO/carbon LIBs anodes.

Operation optimization strategy of a BIPV-battery storage hybrid system

Building integrated photovoltaic (BIPV) system attracts increasing attention of researchers due to environmentally friendly and saving land resource. Combining storage battery with BIPV can improve the flexibility of the entire system, which is promising for distributed renewable energy application. However, how to optimally dispatch the hourly energy flow of PV panel, storage battery and power grid based on a building load is crucial and less investigated. In the paper, a multi-restricted condition nonlinear optimization model is established for a BIPV-battery storage hybrid system under different building loads at a clear day. The optimization model was solved by fmincon function through MATLAB code. In the optimization, overall minimum daily cost including facility cost of the hybrid system, electric price and carbon price were considered as objective function to obtain optimal operation strategy of hourly power distributions of PV, battery and grid for daily building consumption. The key finding indicates that the system has high dependence on power gird when the office building load is heavy, while reduces the depending of power grid as the electrical demand is decreased. Under full-load resident building scenario, when the system with battery cost of 800 Yuan/kW·h or higher, the redundant green power generated by photovoltaic (PV) is sold to power grid in real time to earn extra profit, while the green power is accumulated in the storage batteries as storage battery cost is declined. Moreover, the resident building with BIPV-battery storage hybrid system has less dependence on power gird during day time, realizing self-sufficiency. Under all the scenarios, high storage battery cost limits the capacity of storage battery. And the CO2 emission is reduced as the BIPV-battery storage hybrid system is adopted.