Phenolic Carbon Research Articles

Controllable synthesis of phenolic resin-based carbon aerogel templated by graphene oxide for high-performance supercapacitors

In this work, porous phenol formaldehyde carbon aerogel (PFCA) was facilely manufactured by using simple hydrothermal method and ambient pressure drying. The micromorphology, specific area and electrochemical characteristic of the produced carbon aerogel were examined with scanning electron microscopy, nitrogen adsorption-desorption tests, cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The effects of catalyst and phenol addition, and solvent type on the structure and property have been systematically studied. The results show that the PFCA has a three-dimensional "bead chain" network structure and the typical PFCA-7.5/8 sample exhibits high specific surface area of 759.02 m2 g−1. Moreover, the graphene oxide composited phenol formaldehyde carbon aerogel (GO/PFCA) presenting a lamellar structure was developed by using GO as template. The optimum PFCA-7.5/8 prepared with ethanol as solvent has the best electrochemical performance of 138.33 F g−1 at 5 mV s−1 in 6 M KOH electrolyte, which can be improved to 150.00 F g−1 for the GO/PFCA-3 sample.

Localized eddy current heating-driven synthesis and regeneration of porous carbons at mitigated energy cost

Porous carbons (PCs), widely deployed sorbents in diverse areas, are usually synthesized by thermochemically carbonizing carbonaceous precursors and thermally regenerated at great energy-cost. To seek alternative solutions to such energy penalty and based on the exceptional localized Eddy current heating (LECH) capacity of metal objects upon their exposure to an alternating magnetic field, LECH-driven synthesis of PCs is explored and exemplified by using nickel foam (NF)-delivered LECH to drive carbonization of phenolic resin (PR) infilled within the voids of NF, producing varied PC-incorporated NFs (NF@PCs). Compared with the PCs prepared by using conventional tubular furnace heating, LECH-driven carbonization of PR is able to produce PCs at lower temperature and with greatly enhanced porosity, surface area and graphitization degree, which are mainly resulting from the localized heating nature of LECH. Driven by the same NF-delivered LECH, the moisture adsorbed in the LiCl-loaded NF@PC can be rapidly and completely released at moderate temperature, demonstrating the highly efficient LECH-driven regeneration of PCs. Given that the LECH is delivered by cost-effective and widely available NFs, occurs within the matrix of PR and PC bulk solid, and remotely triggered by an external magnetic field with greatly mitigated energy loss, LECH-driven carbonization of PR and water desorption from PCs thus demonstrated a new, energy-efficient and low-cost strategy to effectively synthesize and regenerate PCs.

Research on fire retardant lignin phenolic carbon foam with preferable smoke suppression performance

In this work, a lignin phenolic carbon foam (LCF) with preferable smoke suppression performance was fabricated by substitute 10 wt.% and 30 wt.% phenol with modified lignin in the traditional process. The result showed that the LCF600s (LCFs carbonized at 600℃) with different lignin percentages showed better smoke suppression performance than the traditional phenolic carbon foam (CF600). The peak smoke production rate (pSPR) and total smoke release (TSR) of LCF600s decreased by 6.90%∼48.28% and 80.91%∼96.28%, and the peak CO production rate and CO yield decreased by 41.17%∼70.59% and 53.80%∼77.79%, respectively. Besides, LCF1-10-600 and LCF2-30-600 displayed the best smoke suppression performance (0020, 0.0015 m2/s of pSPR and 0.61, 2.76 m2/m2 of TSR, respectively). Since the introduced modified lignin significantly increased the amount of benzene rings in the forms, the degree of graphitization of the resulted carbon foams greatly improved, leading to better smoke suppression performance. Furthermore, the added lignin facilitated the preservation of the carbon layer, resulting in reducing smoke production consequently.

Diversity and function of mountain and polar supraglacial DNA viruses

Mountain and polar glaciers cover 10% of the Earth’s surface and are typically extreme environments that challenge life of all forms. Viruses are abundant and active in supraglacial ecosystems and play a crucial role in controlling the supraglacial microbial communities. However, our understanding of virus ecology on glacier surfaces and their potential impacts on downstream ecosystems remains limited. Here, we present the supraglacial virus genome (SgVG) catalog, a 15-fold expanded genomic inventory of 10,840 DNA-virus species from 38 mountain and polar glaciers, spanning habitats such as snow, ice, meltwater, and cryoconite. Supraglacial DNA-viruses were highly specific compared to viruses in other ecosystems yet exhibited low public health risks. Supraglacial viral communities were primarily constrained by habitat, with cryoconite displaying the highest viral activity levels. We observed a prevalence of lytic viruses in all habitats, especially in cryoconite, but a high level of lysogenic viruses in snow and ice. Additionally, we found that supraglacial viruses could be linked to ∼83% of obtained prokaryotic phyla/classes and possessed the genetic potential to promote metabolism and increase cold adaptation, cell mobility, and phenolic carbon use of hosts in hostile environmental conditions using diverse auxiliary metabolic genes. Our results provide the first systematic characterization of the diversity, function, and public health risks evaluation of mountain and polar supraglacial DNA viruses. This understanding of glacial viruses is crucial for function assessments and ecological modeling of glacier ecosystems, especially for the Tibetan Plateau’s Mountain glaciers, which support ∼20% of the human populations on Earth.

3D Carbon Microspheres with a Maze-Like Structure and Large Mesopore Tunnels Built From Rapid Aerosol-Confined Coherent Salt/Surfactant Templating.

Hierarchically porous carbons with tailor-made properties are essential for applications wherein rich active sites and fast mass transfer are required. Herein, a rapid aerosol-confined salt/surfactant templating approach is proposed for synthesizing hierarchically porous carbon microspheres (HPCMs) with a maze-like structure and large mesopore tunnels for high-performance tri-phase catalytic ozonation. The confined assembly in drying microdroplets is crucial for coherent salt (NaCl) and surfactant (F127) dual templating without macroscopic phase separation. The HPCMs possess tunable sizes, a maze-like structure with highly open macropores (0.3-30µm) templated from NaCl crystal arrays, large intrawall mesopore tunnels (10-45nm) templated from F127, and rich micropores (surface area >1000 m2 g-1 ) and oxygen heteroatoms originated from NaCl-confined carbonization of phenolic resin. The structure formation mechanism of the HPCMs and several influencing factors on properties are elaborated. The HPCMs exhibit superior performance in gas-liquid-solid tri-phase catalytic ozonation for oxalate degradation, owing to their hierarchical pore structure for fast mass transfer and rich defects and oxygen-containing groups (especially carbonyl) for efficient O3 activation. The reactive oxygen species responsible for oxalate degradation and the influences of several structure parameters on performance are discussed. This work may provide a platform for producing hierarchically porous materials for various applications.

Response surface optimization of pitch phase change densification using composite phenolic resin co-carbonization to prepare high performance carbon refractories

The response surface method was used to successfully predict the optimal addition amounts of phenolic resin and bitumen binding system for cold isostatic pressing carbon blocks as 14 wt% and 2 wt%, respectively, and ultra-high performance carbon blocks with a compressive strength of 104.25 MPa and pore sizes below 1 µm accounted for 90.8 % were predicted and prepared. We proposed the phase change densification theory for pitch successfully explaining the secondary densification of carbon blocks by pitch powder during shaping and curing. Besides, In the carbonization stage with the carbon block firing schedule, we determined that the carbon structure of pitch after carbonization with the participation of the phenolic resin matrix and organic small molecules of phenolic resin volatilization and pyrolysis consisted of lamellar carbon with a greater number of defects, and proposed that the interface between the non-graphitizable carbon after the carbonization of the phenolic resin and graphitizable carbon after the carbonization of pitch is the carbon binding mode and mechanism of the nucleation and growth of domain structures at the defects of lamellar carbon. Therefore, We determined that the mosaic and fine mosaic binding between the high strength and high brittleness non-graphitizable carbon carbonization of phenolic resin and the low strength and high ductility graphitizable carbon carbonization of pitch as well as the aforementioned carbon binding mechanism based on domain structure also were the important reasons for the performance enhancement of pitch composite phenolic resin bonded carbon blocks.

Poly(vinyl alcohol)/nanocellulose film integrated with phenolic waste-based carbon dots for ultraviolet-blocking and flame retardant applications

Recycling of thermosetting plastic waste and development of functional biopolymer-based films have become captivating issues in the worldwide recently. The current work highlights the facile approach to transform the thermosetting phenolic foam (PF) waste to dual-functional carbon dots (CDs) via simple hydrothermal treatment. The obtained CDs have displayed good graphite structure with rich carbon (C), nitrogen (N), sulfur (S), and phosphorus (P) elements. The absorption peak and quantum yield (QY) values of N, S, P-doped CDs (N,S,P-CDPF) were affected by the hydrothermal precursors and reaction. The fluorescent N,S,P-CDPF derived from PF have further been assembled with the poly(vinyl alcohol) (PVA) and oxidized nanofibrillated cellulose (ONFC) to develop ultraviolet (UV) blocking and flame retardant (FR) films via the solution casting approach. The morphology, transparency, UV–visible behavior, and flame retardancy of the composite films were studied. The light-blocking efficiency and flame retardancy of the films were verified by adjusting the loading ratio of N,S,P-CDPF in the films. The film with 0.05 wt% N,S,P-CDPF can absorb most of UV and some blue light (∼39.6 % at 450 nm), and retain 76.5 % transparency at 800 nm. In addition, the PF-derived N,S,P-CDPF have proved to be good flame retardant owing to the increased limiting oxygen index (LOI) >31.7 %, and reduced heat-release rate (HRR) from 287.4 W/g to 127.2 W/g for the PVA-ONFC@CDPF5 film compared to the pristine PVA film. Finally, the current studies provide a promising strategy for recycling of PF waste as a flame retardant UV absorber and create awareness regarding the flame retardant and flexible UV-blocking packaging materials.

Preparation of spherical porous carbon from lignin-derived phenolic resin and its application in supercapacitor electrodes

Lignin is the most abundant aromatic biomass resource in nature and is the main by-product of paper industry and biorefinery industry, which has the characteristics of abundant source, renewable and low cost. Deep eutectic solvents (DES) are a nascent environmentally friendly solvent option that is gaining traction. DES composed of p-toluenesulfonic acid and choline chloride is used for batch treatment of alkaline lignin, and the bio-oil obtained is ternary polymerized with formaldehyde and phenol to obtain lignin phenolic resin. The porous carbon material is produced through a two-step carbonization process, utilizing phenolic resin derived from lignin as the primary source of carbon. The morphology and composition of the carbon were analyzed by SEM, TEM, XRD, TGA, XPS and Raman spectroscopy, the specific surface area and pore size distribution were analyzed by BET. The results showed that the specific surface area of the lignin-based phenolic resin was significantly higher than that of the pure phenolic resin carbon, and the porous carbon material that was acquired demonstrated a specific surface area of as much as 1026 m2/g. In the three-electrode system, the specific capacitance of DLPFC can reach 245.8 F/g (0.25 A/g), with a very small decrease in the value of specific capacitance at 10,000 cycles, with a retention of 97.62% (10 A/g). The porous carbon demonstrated a specific capacitance of 112.4 F/g at a current density of 0.5 A/g, and the capacitance retention rate could still reach 98.8% after 5000 charge/discharge cycles, with high cycling stability (in the two-electrode system). The prepared symmetrical supercapacitors exhibited high energy density and power density of 3.9 Wh/kg and 125.0 W/kg. The results suggest a new idea of high value-added application of lignin phenolic resin for high-performance supercapacitor electrodes.

Simple Preparation of Lignin-Based Phenolic Resin Carbon and Its Efficient Adsorption of Congo Red

Biomass porous carbon is a low-cost, environmentally friendly material with no secondary pollution and has great potential in the field of dye pollutant adsorption. In this work, we used lignin, a renewable resource abundant in nature, to completely replace phenol and develop a lignin-based phenolic resin carbon (LPFC) adsorbent with high dye removal capacity, high recyclability, and low production cost. The samples were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Then the effects of adsorbent dosage (1 g/L, 2 g/L, 3 g/L, 4 g/L, and 5 g/L), temperature (30 °C, 45 °C, and 60 °C), initial dye concentration (100, 200, 300, 400, 500, 600, 700, and 800 mg/L), and pH (3, 4, 6, 8, 10, and 12) on the adsorption capacity were investigated during the adsorption process. The experimental results showed that the pore structure of LPFC was richer and more graphitized than that of phenolic resin carbon (PFC). The adsorption performance of LPFC on CR was better than that of PFC. The adsorption characteristics of LPFC were investigated from the adsorption isotherm and kinetic perspectives. The Langmuir isothermal adsorption model and the proposed second-order kinetic model were able to fit the adsorption data better. The adsorption process preferred monolayer adsorption, and the proposed second-order model predicted a maximum adsorption capacity of 425.53 mg/g. After five cycles, the removal of CR by LPFC only decreased from 92.1 to 79.2%. It can be seen that LPFC adsorbents have great potential in the field of wastewater treatment and can effectively realize the high-value application of lignin.

Design of Hollow Nanoreactors for Size- and Shape-Selective Catalytic Semihydrogenation Driven by Molecular Recognition.

Mimicking the structures and functions of cells to create artificial organelles spurs the development of efficient strategies for producing hollow nanoreactors with biomimetic catalytic functions, but it is still rarely reported because of the highly challenging fabrication. Here, we report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from molecular-level design strategy, well-defined hollow multishelled structure phenolic resins (HoMS-PR) and carbon (HoMS-C) submicron particles were accurately architected. HoMS-C can serve as an excellent, versatile platform, owing to its tunable properties with tailored functional sites, for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS-C) or externally supported (Pd/HoMS-C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors size-shape-selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS-C for small aliphatic substrates and Pd/HoMS-C for large aromatic substrates. Theoretic calculation provides insights into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work shed the light on rational design and accurate construction of hollow nanoreactors with precise location of active sites and fine-modulated microenvironment by mimicking the functions of cells.

Design of Hollow Nanoreactors for Size‐ and Shape‐Selective Catalytic Semihydrogenation Driven by Molecular Recognition

AbstractMimicking the structures and functions of cells to create artificial organelles has spurred the development of efficient strategies for production of hollow nanoreactors with biomimetic catalytic functions. However, such structure are challenging to fabricate and are thus rarely reported. We report the design of hollow nanoreactors with hollow multishelled structure (HoMS) and spatially loaded metal nanoparticles. Starting from a molecular‐level design strategy, well‐defined hollow multishelled structure phenolic resins (HoMS‐PR) and carbon (HoMS‐C) submicron particles were accurately constructed. HoMS‐C serves as an excellent, versatile platform, owing to its tunable properties with tailored functional sites for achieving precise spatial location of metal nanoparticles, internally encapsulated (Pd@HoMS‐C) or externally supported (Pd/HoMS‐C). Impressively, the combination of the delicate nanoarchitecture and spatially loaded metal nanoparticles endow the pair of nanoreactors with size–shape‐selective molecular recognition properties in catalytic semihydrogenation, including high activity and selectivity of Pd@HoMS‐C for small aliphatic substrates and Pd/HoMS‐C for large aromatic substrates. Theoretical calculations provide insight into the pair of nanoreactors with distinct behaviors due to the differences in energy barrier of substrate adsorption. This work provides guidance on the rational design and accurate construction of hollow nanoreactors with precisely located active sites and a finely modulated microenvironment by mimicking the functions of cells.

Oxygen-Enriched Hierarchical Nanoporous Carbon Electrodes for Supercapacitors

Enhancing the energy storage capacity of carbon electrodes is a key challenge to developing high-performance supercapacitors. In this study, we design an oxygen-enriched hierarchical nanoporous carbon electrode using laser fabrication and subsequent electrochemical activation, which demonstrates superior energy storage capacity. The carbon electrode is first obtained through the carbonization of phenolic resin under instantaneous high temperature induced by laser, resulting in multiple ion transport channels and a specific capacitance of 64.17 mF cm–2 at the current density of 0.2 mA cm–2. To further improve the performance, electrochemical activation is successfully conducted, leading to a 12.1-fold increase of the specific capacitance of the carbon electrodes. It is found that O–C═O-containing functional groups formed during the activation process significantly contribute to the high capacitance enhancement. In a 1 M H2SO4 electrolyte, the activated hierarchical nanoporous carbon electrode delivers a high specific capacitance of 778.3 mF cm–2 under the same test conditions. Additionally, the abundant porous structure and excellent reversibility of redox reaction of the oxygen-containing functional groups enable the assembled supercapacitor to obtain a specific capacitance of 45.3 mF cm–2 at the current density of 0.4 mA cm–2 and maintain a capacitance retention rate of 93.6% after 10,000 charge–discharge tests. This study presents a strategy to prepare carbon electrode materials with both high performance and excellent stability.

Ultrafast and Cost-Effective Fabrication of High-Performance Carbon-Based Flexible Thermoelectric Hybrid Films and Their Devices.

Due to their cost-effectiveness and industry-scale feasibility, carbon-based composites have been considered to be promising thermoelectric materials for low-grade power generation. However, current fabrications for carbon-based composites are time-consuming, and their thermoelectric properties are still low. Herein, we develop an ultrafast and cost-effective hot-pressing method to fabricate a novel carbon-based hybrid film, which consists of ionic liquid/phenolic resin/carbon fiber/expanded graphite. This method only costs no more than 15 min. We found that the expanded graphite as the major component enables high flexibility and the introduction of phenolic resin and carbon fiber enhances the shear resistance and toughness of the film, while the ion-induced carrier migration contributes to a high power factor of 38.7 μW m-1 K-2 at 500 K in the carbon-based hybrid film. After the comparison based on the ratios between the power factor with fabrication time and cost among the current conventional carbon-based thermoelectric composites, our hybrid films show the best cost-effective property. Besides, a flexible thermoelectric device, assembled by the as-designed hybrid films, shows a maximum output power density of 79.3 nW cm-2 at a temperature difference of 20 K. This work paves a new way to fabricate cost-effective and high-performance carbon-based thermoelectric hybrids with promising application potential.

Investigation on a postmortem Al-Al2O3-fused mullite-containing Ti2O3 sliding gate

A resin-bonded Al-Al2O3-fused mullite containing Ti2O3 sliding gate was prepared from metallic Al, tabular alumina and fused mullite containingTi2O3, and was used at the steel-making works. XRD, SEM and EDS analyses were used to investigate the damage mechanism of the postmortem sliding gate. The results show that non-oxide-reinforced phases such as Al4C3, SiC, Al4O4C, Al2OC-AlNss and Ti(C,N)ss are formed which effectively improve the thermal shock and erosion resistance. And the service life of the sliding gate with a fused mullite content of 30 wt% reaches 4 cycles. The phase evolution of the postmortem sliding gate can be described as follows: the oxygen partial pressure is at a very low level due to the active oxidation reaction of the Al. At this time, the Ti2O3 in the fused mullite is unstable and transforms towards the more stable Ti(C,N)ss, while releasing O2. O2 further reacts with the Al to form the highly reactive Al2O(g). The highly reactive Al2O(g), AlN reacts with phenolic resin residual carbon or graphite to form Al2OC-AlNss. As the content of high titanium fused mullite increases, Al4O4C and Al4C3 gradually transform into the more stable Al2OC-AlNss and Ti(C,N)ss. The introduction of Al and high titanium fused mullite enables the synergistic formation of high performance Ti(C,N)ss and Al2OC-AlNss.

Qualitative and Quantitative Changes in Soil Organic Compounds in Central European Oak Forests with Different Annual Average Precipitation

The various climate scenarios consistently predict warming and drying of forests in Hungary. Soils play a significant role in the long-term sequestration of atmospheric CO2, while in other cases they can also become net carbon emitters. Therefore, it is important to know what can be expected regarding future changes in the carbon storage capacity of soils in forests. We used precipitation gradient studies to solve this problem, using a type of “space–time” substitution. In this research, we primarily examined the quality parameters of soil organic matter (SOM) to investigate how climate change transforms the ratio of the main SOM compound groups in soils. For our studies, we applied elemental and 13C and 15N isotopic ratio analysis, NMR analysis, FT-IR spectra analysis, thermogravimetric and differential thermal analyses to measure SOM chemistry in samples from different oak forests with contrasting mean annual precipitation from Central Europe. Our results showed that soil organic carbon (SOC) was lower in soils of humid forests due to the enhanced decomposition processes and the leaching of Ca, which stabilizes SOM; however, in particular, the amount of easily degradable SOM compounds (e.g., thermolabile SOM, O-alkyl carbon, carboxylic and carbonyl carbon) decreased. In dry forest soils, the amount of recalcitrant SOM (e.g., thermostable SOM, alkyl carbon, aromatic and phenolic carbon and organo–mineral complexes stabilized by Ca increased, but the amount of easily degradable SOM increased further. The main conclusion of our study is that SOC can increase in forests that become drier, compensating somewhat for the decrease in forest plant biomass.

Thermal Ablation Experiments of Carbon Phenolic and SiC-Coated Carbon Composite Materials Using a High-Velocity Oxygen-Fuel Torch

For future spacecraft TPS (heat shield) applications, ablation experiments of carbon phenolic material specimens with two lamination angles (0° and 30°) and two specially designed SiC-coated carbon-carbon composite specimens (with either cork or graphite base) were conducted using an HVOF material ablation test facility. The heat flux test conditions ranged from 3.25 to 11.5 MW/m2, corresponding to an interplanetary sample return re-entry heat flux trajectory. A two-color pyrometer, an IR camera, and thermocouples (at three internal locations) were used to measure the specimen temperature responses. At the 11.5 MW/m2 heat flux test condition, the 30° carbon phenolic specimen's maximum surface temperature value is approximately 2327 K, which is approximately 250 K higher than the corresponding value of the SiC-coated specimen with a graphite base. The 30° carbon phenolic specimen's recession value is approximately 44-fold greater, and the internal temperature values are approximately 1.5-fold lower than the corresponding values of the SiC-coated specimen with a graphite base. This indicates that increased surface ablation and a higher surface temperature relatively reduced heat transfer to the 30° carbon phenolic specimen's interior, leading to lower internal temperature values compared to those of the SiC-coated specimen with a graphite base. During the tests, a phenomenon of periodic explosions occurred on the 0° carbon phenolic specimen surfaces. The 30° carbon phenolic material is considered more suitable for TPS applications due to its lower internal temperatures, as well as the absence of abnormal material behavior as observed in the 0° carbon phenolic material.

Vacuum-Dried and Intrinsic Photothermal Phenolic Carbon Aerogel from Coal Tar Rich in Polycyclic Aromatics for Efficient Solar Steam Generation

Solar steam generation has been proven to be an efficient way for obtaining clean water from seawater or polluted water with solar energy as the only energy input. Due to the high porosity and light absorption, tunable micro–nano structure, and excellent thermal insulation, carbon aerogels as photothermal materials have attracted much attention. However, requirements of freeze drying and additional light absorbers as well as low strength restrict the large-scale utilization of carbon aerogels. Herein, self-floating and low-cost coal tar-based phenolic carbon aerogels (CPCAs) were fabricated using a facile method, that is, polymerization/gelation, vacuum drying, and carbonization. CPCAs with comparable light absorption (96.6%) to carbon nanotube can be used as intrinsic photothermal materials owing to the existence of considerable polycyclic aromatics in coal tar. In addition, CPCAs possess hierarchical porous architectures and abundant polar functional groups, delivering fast water transportation. Moreover, the latent heat is obviously reduced due to the regulation of the water state. Therefore, the evaporation rate can reach up to 2.23 kg m–2 h–1 with an energy efficiency of 92.5% under 1 sun employing a CPCA as a photothermal material. Additionally, CPCAs with high strength (more than 4 MPa under 90% compressive strain) have versatile applications in seawater desalination and industrial wastewater for long-term stability. The excellent performance of CPCAs was tentatively revealed by density functional theory and COMSOL calculation.

Relations of Phenolic Compounds, Tannins, Lignin, Nitrogen and Carbon in Plants of the Empetro-Piceetum Forests of the Kola Peninsula

The study presents an analysis of aging (falling) organs (leaves/needles) of the following plants: Siberian spruce (Picea abies ssp. obovata (Ledeb.) Domin), downy birch (Betula pubescens Ehrh), common cowberry (Vaccinium vitis-idaea L.), crowberry hermaphroditic (Empetrum hermaphroditum Hager.), blueberry (Vaccinium myrtillus L.), Schreber’s pleurium (Pleurozium schreberi (Brid.) Mitt.), polytrichum (Polytrichum spp.), dwarf cornel (Chamaepericlymenum suecicum (L.) Aschers. Graebn. (Cornus suecica L.)), wavy hair-grass (Deschampsia flexuosa (L.) Trin.). A significant variation in the chemical composition (the content of lignin, phenolic compounds, tannins, nitrogen and carbon, as well as the stoichiometric ratios “C/N”, “lignin/N”, “lignin/cellulose”) was found among plants of the northern taiga forests at the interspecific level. The influx of secondary metabolites with litter depends on the plant communities’ species composition and the contribution of various plant species to the vegetation cover’s composition. At the intraspecific level (for Siberian spruce growing in different landscape positions within empetro-piceetum forests (in automorphic, transit and accumulative landscapes)) an increase in the content of soluble tannins (p 0.05) in spruce needles from the automorphic positions of landscape was determined. Also have been studied some interrelations between secondary metabolites, nitrogen and carbon in the composition of aging photosynthetic organs of dominant plant species in northern taiga empetro-piceetum forests.

Microstructure regulation of resin-based hard carbons via esterification cross-linking for high-performance sodium-ion batteries

A phenolic resin-based carbon heterostructure with advanced Na-storage performance was prepared by regulating its pyrolysis process via an esterification cross-linking reaction.

Preparation of Advanced Multi-Porous Carbon Nanofibers for High-Performance Capacitive Electrodes in Supercapacitors.

The booming demand for energy storage has driven the rapid development of energy storage devices such as supercapacitors, and the research on high-performance electrode materials, a key component of supercapacitors, has gained tremendous attention. In this research, phenolic resin-based multi-porous carbon nanofibers have been prepared by electrospinning, curing, carbonization and activation and then employed as advanced electrode materials in supercapacitors. We demonstrate that the material is nano-scale continuous fiber, and its surface has pore distribution of different sizes. It delivers a high specific capacitance of 242 F g-1 at a current density of 0.2 A g-1 and maintains 148 F g-1 even at a high current density of 20 A g-1. Moreover, it shows almost no capacitance decay at a current density of 2 A g-1 over 1000 cycles, demonstrating its great potential as high-performance electrodes in supercapacitors.