Traditional Carbon Materials Research Articles

Rhodium nanoparticles anchored on 3D metal organic framework-graphene hybrid architectures for high-performance electrocatalysts toward methanol oxidation

The development of advanced and efficient anode catalysts to accelerate the kinetic rate of methanol oxidation plays an important role in the large-scale commercial application of the direct methanol fuel cells (DMFCs). Herein, we report the design and construction of small-sized rhodium nanocrystals decorated on 3D hybrid aerogels built from graphene and metal-organic framework (Rh/G-ZIF) via a solvothermal co-assembly method. Benefiting from the 3D rigid crosslinked architecture, abundant porous channels, and highly dispersed ultrafine Rh nanoparticles, the optimized Rh/G-ZIF aerogel exhibits a large electrochemically active surface area, high mass and specific activities, and excellent long-term durability toward the methanol electrooxidation, all of which are significantly superior to those of Rh catalysts supported by traditional carbon materials (such as carbon black, carbon nanotube, and graphene).

Research progress on carbon materials as negative electrodes in sodium‐ and potassium‐ion batteries

AbstractCarbon materials, including graphite, hard carbon, soft carbon, graphene, and carbon nanotubes, are widely used as high‐performance negative electrodes for sodium‐ion and potassium‐ion batteries (SIBs and PIBs). Compared with other materials, carbon materials are abundant, low‐cost, and environmentally friendly, and have excellent electrochemical properties, which make them especially suitable for negative electrode materials of SIBs and PIBs. Compared with traditional carbon materials, modifications of the morphology and size of nanomaterials represent effective strategies to improve the quality of electrode materials. Different nanostructures make different contributions toward improving the electrochemical performance of electrode materials, so the synthesis of nanomaterials is promising for controlling the morphology and size of electrode materials. This paper reviews the progress made and challenges in the use of carbon materials as negative electrode materials for SIBs and PIBs in recent years. The differences in Na+ and K+ storage mechanisms among different types of carbon materials are emphasized.

Visualizing the landscape and evolution of capacitive deionization by scientometric analysis

Capacitive deionization (CDI) as an emerging desalination technology attracts increasing attention due to its advantages such as low cost, environmental friendliness, simple operation, and large water recovery. This study presents a systematic, objective, and comprehensive review of CDI research via scientometric analysis. The dataset was collected from Web of Science and analysed by software Biblioshiny, VOSviewer and CiteSpace. After analysing a sum of 2270 documents, we identified the most influential journals, countries, institutions, authors, and publications. We also mapped the networks of co-authorship, co-citation, and keywords co-occurrence. Desalination has the largest number of publications in CDI. China is the country with the largest number of publications, and Egypt has the highest level of international collaboration. The keyword and cluster analyses demonstrate the evolution of CDI electrodes from traditional carbon materials through carbon-based nanomaterials to Faradaic materials and the diversification of CDI cell architectures. The timeline visualization displays five popular research topics, including electrode materials, charge efficiency, water salinity, CDI cell architectures, and selective removal. Moreover, we provided several recommendations for future research. This article will give authors an intuitive understanding of the research status, frontier topics, and emerging trends in CDI.

Synthesis of composite TiO2/CNTs via sol-gel route as electrode materials for supercapacitors

Supercapacitor is considered as a promising energy storage devices because supercapacitors can provide higher power densities than lithium-ion batteries. Besides traditional carbon materials, the development of metal oxide composite materials with carbon is considered a new direction to improve the weaknesses of current supercapacitors. The metal oxide composite nanomaterial not only offers high charge storage capacity, but also improves the discharge efficiency and life cycle of the supercapacitor. In this study, TiO2/CNTs nanocomposite materials (with CNTs ratio of 0.5% and 1%, respectively) were synthesized by sol-gel route and considered as electrode materials for supercapacitor. The composite materials were investigated by structural and morphological analysis methods, which showed the addition of CNTs did not change the original material structure; besides, the presence of CNTs improve the porous structure of TiO2 to support the penetration of the electrolyte. Cyclic voltammetry results showed the efficiency of CNTs addition through the increase of specific capacitance from 171 F/g (K0 sample) to 205 F/g (K1 sample). The EIS spectrum also shows the role of CNTs in the composite when reducing the internal resistance as well as the charge transfer resistance in the high frequency region. The galvanostatis cycling performance showed that K1 (with 1% CNTs) had the highest capacitance, reaching 128 F/g and remained stable after 2000 cycles at a current density of 1 A/g in the region potential 0-1.8 V.

ОЦЕНКА ПОВЕРХНОСТИ УГЛЕРОДНОГО МАТЕРИАЛА ПУТЕМ ЕМКОСТНЫХ ИЗМЕРЕНИЙ ДВОЙНОСЛОЙНОГО СУПЕРКОНДЕНСАТОРА

The paper considers the possibility of calculating the surface of carbon materials by measuring the capacitance of symmetric supercapacitors. It is shown that this approach allows us to obtain results that are in good agreement with the BET method. Traditional carbon materials for symmetric supercapacitors - activated carbons and carbon composites based on carbon black - are considered and compared. The capacitances of supercapacitors at different charge rates were measured in the work. When using the exponential model for almost all samples, the values of the maximum possible specific area of the sorbed ions are close to the specific surface of the materials calculated by the BET method. The exception is SX1G, for which a twofold difference between the values of specific areas is observed. This difference may be due to the non-equipotential, mostly microporous structure of the material, which is difficult for large solvated cations. Based on the experimental data obtained, it was suggested that it is possible to estimate the specific surface area of carbon materials based on the calculated capacitance. An important conclusion for practice is made - the limit of supercapacitor capacity growth is reached for materials with a specific surface area of 1500 m2/g

Sustainable and Conductive Wood‐Derived Carbon Framework for Stretchable Strain Sensors

AbstractConductive carbon materials have recently received increasing interest for their potential applications in wearable electronics and electronic skins because of their adjustable structure and resistance. However, high cost, large energy consumption, and potential biological toxicity put a huge obstacle in the way of practical application in electronics. Bio‐derived carbon, which possesses sustainability and low cost, is an ideal substitute for traditional carbon materials. Here, a facile and eco‐friendly strategy is proposed to fabricate a lamellar wood‐derived carbon framework with excellent electrical conductivity for stretchable strain sensors. The obtained carbonized delignified wood framework (CDWF) possesses higher conductivity (5.62 S cm−1), and larger specific surface area (35.42 m2 g−1) as compared with carbonized wood framework (CWF). Moreover, the CDWF can be utilized to assemble a stretchable strain sensor by encapsulating it into polydimethylsiloxane (PDMS). The CDWF‐based sensor exhibits favorable stretchability, stability, and durability (5000 cycles). The outstanding sensing properties of the sensors enable it to measure the joint movement of the human body accurately and continuously, showing good prospects for human physical monitoring and wearable devices applications.

Identification of active sites of B/N co-doped nanocarbons in selective oxidation of benzyl alcohol

Developing highly active and stable nanocarbon catalysts for selective oxidation reactions has attracted much attention due to their potential as an alternative to traditional metal-based or noble metal catalysts. However, the nature of active sites and the reaction mechanism of nanocarbon catalysts for oxidation reactions still remains largely unknown, which hinders the rational design and development of highly efficient carbon-based catalysts. Here we report a facile strategy for the synthesis of boron and nitrogen co-doped carbon nanosheet material (BNC), which exhibits excellent catalytic activity with 91% conversion and 99% selectivity in selective oxidation of benzyl alcohol into benzaldehyde, superior to those of traditional carbon materials (oxidized carbon nanotubes, graphites and commercial nanocarbons). Structural characterizations and kinetic measurements are studied to clarify the active site, in which phenolic hydroxyl on BNC is responsible for the production of benzaldehyde. Meanwhile, we put forward a possible reaction mechanism and point out the key factors in determining the reactivity for this reaction. Therefore, the present work provides new insight into structure–function relationships, paving the way for the development of highly efficient nanocarbon catalysts.

Vertical 2-dimensional heterostructure SnS-SnS2 with built-in electric field on rGO to accelerate charge transfer and improve the shuttle effect of polysulfides

Traditional carbon materials as sulfur hosts of Li-sulfur(Li-S) cathodes have slightly physical constraint for polysulfides, due to their no-polar property. Therefore, it is necessary to further enhance the affinity between sulfur hosts and polysulfides, and relieve the shuttle effects in the Li- S batteries. Herein, we report a novel vertical 2-dimensional (2D) p-SnS/n-SnS2 heterostructure sheets which grown on the surface of rGO. The excellent electrochemical properties of SnS-SnS2@rGO as Li-S cathode are ascribed to the stronger absorption effect of metal sulphides for polysulfides and the smooth trapping-diffusion-conversion effect of p-SnS/n-SnS2 heterostructure for polysulfides. As a conductive carrier for the growth of vertical 2D p-SnS/n-SnS2 heterostructure nanosheets, rGO can protect the steadiness and enhance the cycle stability of electrode, compared with heterostructure without rGO. In addition, the built-in electric field in the 2D p-SnS/n-SnS2 heterostructure during the discharge/charge processes can effectively accelerate charge transfer, and the charge transfer mechanism in SnS-SnS2 heterostructure during cycling has been investigated. At a rate capability of 2C, the designed SnS-SnS2@rGO as Li-S cathode delivers high specific capacities of 907 mAh g−1 and 571 mAh g−1 after the first cycle and 500 cycles, respectively, which shown excellent cycling ability.

Carbon nanodot modified N, O-doped porous carbon for solid-state supercapacitor: A comparative study with carbon nanotube and graphene oxide

Herein, a series of nanocarbons, including carbon nanodots (CD), carbon nanotubes (CNT) and graphene oxide (GO), modified N, O doped hierarchical porous carbons (NOHPC) were prepared by carbonization using the silica nanospheres and ZnCl2 as templates. The N, O doping content, N, O species and the ratio of micro/mesopore pore structures of NOHPC can be effectively improved by the modification of nanocarbons in organic precursor of polyacrylonitrile. The as-prepared CD modified NOHPC (CD/NOHPC) showed superior capacitance performance than that of CNT (CNT/NOHPC) and GO (GO/NOHPC), and the CD/NOHPC exhibited a high specific capacitance of 343.6 F g−1 at a current density of 1 A g−1 and an excellent rate capability (304.7 F g−1 at 50 A g−1 and 88.7% capacitance retention). The symmetric supercapacitor of CD/NOHPC delivered an energy density of 10.3 Wh kg−1 (0.31 mWh cm−3) at a power density of 489 W kg−1 (14.7 mW cm−3), a capacitance retention of 109% after 20000 galvanostatic charge/discharge cycles in H2SO4/PVA solid-state electrolyte. The systematic study clarified that CD can be utilized for the regulation and improvement of the internal structure of traditional porous carbon materials, resulting in better electrochemical energy storage than that of CNT and GO.

Amidoximated wooden solar evaporator for high-efficiency nuclear wastewater treatment.

The efficient removal of uranium (VI) (UO22+) is of great significance to the ecological environment. However, there is still a lack of efficient adsorption materials to remove UO22+ in wastewater economically. Because natural basswood has high porosity, natural hydrophilicity, and abundant surface functional groups, wood as a support material has a good application prospect in water treatment. In the present work, the amidoxime functional group (AO) is grafted to the hydroxyl group of the wood fiber (AO-wood). A carbon layer is formed on the surface of the basswood by heating, and some Ag nanoparticles with good optothermal effect are added to the wood tunnel (Ag-C-AO-wood). Ag-C-AO-wood is used for efficient wastewater treatment under light conditions. The adsorption kinetic of Ag-C-AO-wood is 4.6 h under one irradiation, which is 7 times faster than AO-wood. It has approached or even surpassed some traditional carbon materials with stirring. This method is expected to break the traditional stirring method. Ag-C-AO-wood can not only remove uranium up to 82% but also have a good removal efficiency (27%) on iodide ions. More importantly, due to basswood characteristics, it is possible to large-scale preparation and explore its potential application value in wastewater.

Preparation of hollow carbon rods by using ZnO as template for high-performance supercapacitor

Supercapacitors possess prominent advantages compared to traditional capacitors or batteries and have been increasingly attracting attentions for their application in energy storage. Carbon materials are the most highly used material for supercapacitors due to the unique characters. However, traditional carbon materials fail to meet up-to-date energy storage application, which requires to develop new carbon structure with superior performances. Herein, we developed a new hollow carbon rods (HCR) using ZnO@ZIF-8 rods as a template. We first achieved ZnO@ZIF-8 rods using ZnO as a template. Then, ZnO@ZIF-8 rods were transformed into ZnO@C, which was further transformed into HCR by removal of ZnO. The result shows that the HCR-800 exhibited high specific capacitance of 228.3 F/g and good cycling stability of retaining 96.51% after 10,000 cycles in 2 M KOH under -1–0 V at 1 A/g. Together, our newly developed HCR has unique structure and superior characteristics and is promising to improve the performances of supercapacitors.

The graphitization of a highly oriented graphite precursor prepared under a high magnetic field of 6 T

Traditional carbon materials such as graphite are currently extremely useful and have recently been applied to cutting-edge materials. However, it is a concern that as production will increase much more in the future, the impact on the environment during preparation will become a problem. Recently, we have succeeded in obtaining an extremely high orientation structure using a carbonization process in a strong magnetic field [“Magnetic orientation of hexagonal carbon layers at high temperature” Chem. Lett. 41, 1576 (2012)]. Because graphite has a two-dimensional structure in which graphene sheets are laminated, we expect that graphitization should be easily performed by using a precursor that originally has an oriented structure. When two types of precursors prepared in the absence and presence of a magnetic field of 6 T were graphitized under the same conditions, graphitization was promoted by 50 to 100 K for the precursor to which a strong magnetic field was applied. If we fabricate products with the same degree of graphitization, it is calculated that the graphitization energy can be suppressed by as much as 10% by using a magnetic field. Applying this technology to the preparation of graphite in industry is proposed to result in substantial energy savings.

Sustainable biocarbon materials derived from Lessonia Trabeculata macroalgae biomass residue for supercapacitor applications

AbstractValue addition of waste (or) residual biomass gain more interest because it comes under the category of “waste to wealth” and creates new pathway to biorefinery processes. Owing to high carbon contents, residual biomasses are considered as a potential raw material for the preparation of biocarbon materials which are eco‐friendly and can be the alternate for traditional carbon materials. This study reports the preparation of pristine and activated biocarbon materials using Lessonia Trabeculata macroalgal residual biomass as carbon source by thermochemical process. The physiochemical properties of the synthesized biocarbon materials were investigated through powder X‐ray diffraction, Fourier transform infrared, Raman, and X‐ray photoelectron spectroscopy, scanning electron microscopy and Brunauer‐Emmett‐Teller surface area analyses. The activated biocarbon resulted higher specific surface area (769 m2/g) than pristine biocarbon (60 m2/g). Both pristine and activated biocarbon were used to fabricate electrodes for symmetric supercapacitor and the assembled capacitive cells showed the specific capacitance of 45.2 and 81.6 F g−1, respectively, at 1 A g−1 specific current using 1 M potassium hydroxide electrolyte. Also, the fabricated biocarbon materials showed excellent capacitance retention (96%) during 500 cycles. The results indicate that the activated carbon prepared from residual macroalgal biomass have more promising application scope in the field of supercapacitors.

Recent Progress in Graphdiyne for Electrocatalytic Reactions

AbstractAs a burgeoning carbon material, graphdiyne (GDY) with a highly π‐conjugated structure that is composed of sp‐ and sp2‐hybridized carbon atoms, it can be grouped into several forms. Compared to traditional carbon materials, GDY exhibits a unique carbon network and electronic structure, raising the concern of researchers at home and abroad. As a result of its favorable electronic structure and good functionalization capability, GDY can be modified to provide an ideal platform to prepare a highly active catalyst for electrocatalytic reactions. Furthermore, GDY can be synthesized on arbitrary substrates in a three‐dimensional nanosheet array structure, which can provide a large number of channels for the transfer of electrons and a large contact area with the reactant, which is also beneficial for electrocatalytic reactions. This Review focuses on the recent development of GDY for electrocatalysis applications, and elaborates the future prospects of GDY.

Combined DFT and experiment: Stabilizing the electrochemical interfaces via boron Lewis acids

Combined DFT and experiment, the boron configurations which show different Lewis acidity on B-doped graphene are identified stabilizing effect to electrochemical interfaces and promoting the performance of supercapacitors. The incorporation of boron into carbon material can significantly enhance its capacity performances. However, the origin of the promotion effect of boron doping on electrochemical performances is still unclear, in part due to the inadequate exposure of boron configurations resulting from the complexity of traditional carbon materials. To overcome this issue, herein, a series of boron-doped graphene with highly-exposed boron configurations are prepared by tuning annealing temperature. Then the correlation between boron configurations and the electrochemical performances is investigated. The combination of density-functional theory (DFT) computation and NH 3 -TPD/Py-FTIR indicates that the BCO 2 configuration formed on the surface of graphene is easier to accept lone-pair electrons than BC 2 O and BC 3 configurations due to the stronger Lewis acidity. Such an electronic structure can effectively reduce the number of unstable electron donors and stabilize the electrochemical interface, which is proved by NMR, and critical for improving the electrochemical performances. Further experiments confirm that the optimized BG800 with the largest amount of BCO 2 configuration presents ultralow leak current, improved cyclic stability, and better rate performance in SBPBF 4 /PC. This work would provide an insight into the design of high-performance boron-doped carbon materials towards energy storage.

A simple synthesis of highly ordered microporous carbon nanospheres for high performance potassium-ion batteries

Potassium-ion batteries (PIBs) are considered as a promising alternative to lithium-ion batteries (LIBs) for low cost and large-scale application. However, owing to the large size of K ions, traditional carbon materials still undergo poor rate performance, low capacity and unsatisfied cycling life. Herein, we design and synthesize highly ordered microporous carbon nanospheres (OMCNSs) for the first time through a very simple method. In PIBs, OMCNSs negative electrode deliver an ultrahigh capacity of 256.9 mA h g−1 at 0.5 A g−1 after 500 cycles, outstanding rate performance of 156.6 mA h g−1 at 5 A g−1 after 2000 cycles. Furthermore, when coupled with potassium Prussian blue positive electrode, the potassium-ion full cells also display outstanding electrochemical performance, highlighting the practicability of OMCNSs. The excellent electrochemical performance is ascribed to the highly ordered micropores, which increase the action of physical adsorption and trap K+ stably.

Enhanced microwave absorption of epoxy composite by constructing 3D Co–C–MWCNTs derived from metal organic frameworks

In this study, a magnetic/dielectric composite precursor is obtained by in situ growing zeolitic imidazolate framework-67 nanoparticles on the surface of acidified multi-walled carbon nanotubes (MWCNTs). After pyrolyzing the precursor in an argon atmosphere, a kind of nano-heterogeneous composite wave absorber was prepared. Subsequently, a new type of magnetic/dielectric wave-absorbing composite was prepared by heating and curing Co–C–MWCNTs and epoxy resin, and the properties of the composite were adjusted by changing the content of Co–C–MWCNTs. A variety of modern characterization methods were used to systematically study the micro-morphology, element composition and electromagnetic properties of the composite. The results show that after the combination of MWCNTs and Co–C particles with regular dodecahedron structure, a special synergistic effect appears. The addition of magnetic MOF derivatives not only improves the impedance matching characteristics of the composite and increases the magnetic loss mechanism, but also provides a new path for the transmission of electromagnetic waves because of its special pore structure and the three-dimensional network structure formed by cross-linking with MWCNTs. The interface polarization and multiple scattering effects greatly improve the attenuation efficiency of electromagnetic waves. In X-band (8–12 GHz), the Co–C–MWCNTs/EP composite with a loading of 17.5 wt% can achieve an effective absorption bandwidth of 2.38 GHz when the matching thickness is 1.6 mm. The combination of novel MOF-derived materials and traditional carbon materials is expected to provide new ideas for the design of composites with microwave absorption capabilities.

Using Different Powdered Carbon Forms for Reinforcing Aluminum Composite Materials with Carbon and Titanium Carbide: A Review

The use of both traditional powdered carbon materials (graphite, soot, charcoal, and shungite) and novel carbon nanomaterials (nanodiamonds, fullerene, nanotubes, and graphene) as a dispersed reinforcing phase in aluminum matrix composites (AMCs) and as reagents for the synthesis of reinforcing particles of titanium carbide (TiC) in AMCs is considered. It is noted that the main direction of AMC development to significantly improve the mechanical properties consists of the transition from micron-sized reinforcing particles to nanoparticles, and that the use of novel carbon nanomaterials could play a decisive role in this case. It is necessary that the technologies for producing such AMCs provide the appropriate parameters of the nanoparticles, their uniform distribution throughout the matrix, and a strong adhesive interfacial bond with the matrix. However, the implementation of these technological requirements is a great problem, since carbon and titanium carbide nanoparticles cannot be wetted by aluminum at a temperature below 1000°C and are prone to the formation of agglomerates from nanoparticles owing to interparticle adhesive forces, the magnitude of which increases to the greatest extent with a decreasing particle size. An overview of the achievements and unresolved issues in the use of powdered carbon forms in different solid-phase and liquid-phase methods for manufacturing AMCs based on various techniques is presented. It is shown that the potentialities of using traditional carbon materials are not still exhausted. Considerable attention is paid to the use of self-propagating high-temperature synthesis (SHS) for obtaining reinforcing titanium carbide particles with the use of different carbon materials to produce AMCs.

Application of different powdered forms of carbon for reinforcement of aluminum matrix composite materials by carbon and titanium carbide. А review

The paper considers the use of both traditional powdered carbon materials (graphite, soot, charcoal, shungite) and new carbon nanomaterials (nanodiamonds, fullerene, nanotubes, graphene) as a dispersed reinforcing phase in aluminum matrix composites (AMCs), and as reagents for the synthesis of titanium carbide (TiC) reinforcing particles in AMCs. It is observed that the key area of AMC development for significant improvement of their mechanical properties is the transition from micron-sized reinforcing particles to nanoparticles, and that the use of new carbon nanomaterials can play a decisive role in this. The technologies for producing such AMCs must provide the appropriate parameters of nanoparticles, their uniform distribution in the matrix and a strong adhesive interfacial bond with the matrix. However, it is highly difficult to meet these process requirements since carbon and titanium carbide nanoparticles are not wetted with aluminum at temperatures below 1000 °C and are prone to nanoparticle agglomeration due to interparticle adhesive forces that increase dramatically with the decreasing particle size. The paper provides an overview of advancements and unresolved issues in the use of powdered carbon forms in various solid-phase and liquid-phase methods of AMC production using various techniques to address these process challenges. It is shown that there is still a potential for using traditional carbon materials as well. Considerable attention is paid to the self-propagating high-temperature synthesis (SHS) of titanium carbide reinforcing particles with various carbon materials used to obtain aluminum matrix composites.

Harvesting Electricity from CO2 Emission: Opportunities, Challenges and Future Prospects

The ever-increasing CO2 emission has necessitated the search for suitable technologies for CO2 utilization at a low cost. Recently, a novel concept called reactive gas electrosorption (RGE) for energy harvesting from CO2 emission, which could boost the efficiency of a thermal power plant by 5% was proposed by Hamelers and coworkers. The concept involves mixing of air stream with a low CO2 concentration with a stream of high CO2 concentration in an alkaline aqueous electrolyte. However, this concept is faced with the challenges of designs specific for CO2-electrolyte, and inadequate performance of the electrode materials. Therefore, this study showcases electricity generation opportunities from CO2 via RGE and discussed challenges and prospect. The study reveals that the drawback relating to the electrode could be solved using heteroatom doped traditional carbon materials and composite carbon-based materials, which has been successfully used in capacitive cells designed for desalination. This modification helps to improve the hydrophilicity, thereby improving electrode wettability, and suppressing faradaic reaction and co-ion repulsion effect. This improvement could enhance the charge efficiency, sorption capacity durability of electrodes and reduce the energy loss in RGE. Moreover, intensification of the membrane capacitive deionization (MCDI) process to obtain variances like enhanced MCDI and Faradaic MCDI. Hybrid capacitive deionization (HCDI) is also a promising approach for improvement of the capacitive cell design in RGE. This intensification can improve the electrosorption capacity and minimize the negative effect of faradaic reaction. The use of alternative amine like Piperazine, which is less susceptible to degradation to boosting CO2 dissolution is also suggested.