From Allergens to Battery Anodes: Nature-Inspired, Pollen Derived Carbon Architectures for Room- and Elevated-Temperature Li-ion Storage

The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like, and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.

Integration of inorganic nanostructures with polydopamine-derived carbon: tunable morphologies and versatile applications

Polydopamine (PDA), a mussel adhesive-inspired biomimetic polymer, has attracted tremendous attention owing to its extremely versatile adhesion properties, facile aqueous coating process, capability of self-assembly to form nanostructures, and abundant surface functional groups for secondary modification. PDA is also a fantastic carbon source because it gives nitrogen (N)-doped graphite-like carbon in high yield, and the carbonized PDA (C-PDA) thin coatings have similar properties to those of N-doped multilayered graphene, i.e., they exhibit high electrical conductivity, and good electrochemical and mechanical properties. In comparison with other carbon sources, an outstanding feature of PDA lies in its ease of integration with inorganic nanostructures and capability for easy tailoring the structure and morphology of the resultant composite nanostructures. In this article, different routes for the preparation of C-PDA-based composite nanostructures, such as carbon/metal oxide and carbon/Si hollow, mesoporous, core-shell, yolk-shell nanostructures, are introduced with typical examples. The structures, morphologies and properties of the C-PDA-based composite nanostructures are also reviewed, and their potential applications in various engineering fields, such as energy storage, solar water splitting, flexible electronics, catalysis, sensing and environmental engineering, are highlighted. Finally a future outlook for this fascinating composite-nanostructure enabler is also presented.

Nitrogen-Doped Banana Peel-Derived Porous Carbon Foam as Binder-Free Electrode for Supercapacitors

Nitrogen-doped banana peel-derived porous carbon foam (N-BPPCF) successfully prepared from banana peels is used as a binder-free electrode for supercapacitors. The N-BPPCF exhibits superior performance including high specific surface areas of 1357.6 m²/g, large pore volume of 0.77 cm³/g, suitable mesopore size distributions around 3.9 nm, and super hydrophilicity with nitrogen-containing functional groups. It can easily be brought into contact with an electrolyte to facilitate electron and ion diffusion. A comparative analysis on the electrochemical properties of BPPCF electrodes is also conducted under similar conditions. The N-BPPCF electrode offers high specific capacitance of 185.8 F/g at 5 mV/s and 210.6 F/g at 0.5 A/g in 6 M KOH aqueous electrolyte versus 125.5 F/g at 5 mV/s and 173.1 F/g at 0.5 A/g for the BPPCF electrode. The results indicate that the N-BPPCF is a binder-free electrode that can be used for high performance supercapacitors.

Facile self-templating preparation of polyacrylonitrile-derived hierarchical porous carbon nanospheres for high-performance supercapacitors

The article reports a polyacrylonitrile-derived hierarchical porous carbon nanospheres as high-performance supercapacitors via a green, facile and efficient strategy.

Construction of 3D nanostructure hierarchical porous graphitic carbons by charge-induced self-assembly and nanocrystal-assisted catalytic graphitization for supercapacitors

A smart and sustainable strategy based on charge-induced self-assembly and nanocrystal-assisted catalytic graphitization is explored for the efficient construction of 3D nanostructure hierarchical porous graphitic carbons from the pectin biopolymer.

Application of ordered mesoporous carbon in solid phase microextraction for fast mass transfer and high sensitivity

High-surface-area ordered mesoporous carbon-coated fiber exhibits a large adsorption amount, fast mass transport and high sensitivity, presenting an attractive potential candidate for pollution enrichment and detection in environmental samples.

Pt decorated Artocarpus heterophyllus seed derived carbon as an anode catalyst for DMFC application

A carbohydrate rich biomass is hydrothermally carbonized and thermally degraded to sequester high surfaced carbon. Subsequently, the prepared carbon is decorated with Pt NPs and is executed as an anode catalyst for methanol oxidation reaction (MOR).

Scalable preparation of monodisperse micron-sized carbon microspheres and their application in anion-exchange chromatography

Polyacrylic acid sodium (PAAS), which is an anionic water-soluble polymer, is widely utilized as a thickener in the food industry and flocculant in water treatment owing to its high anion density, low cost and nontoxicity.

Sustainable carbon-sheets and their MnO–C hybrid for Li-ion batteries

Sustainable carbon have been achieved by a simple treatment of sugarcane-stalk, which exhibits superior electrochemical behavior to graphite. Moreover, the performance can be further upgraded by growing MnO to form a synergetic MnO–C hybrid.

Tailored activated carbons for supercapacitors derived from hydrothermally carbonized sugars by chemical activation

“Sugar”-supercapacitors: analyses of textural properties revealed that the specific capacitances for glucose derived-activated carbons correlated most strongly with ultramicropores.

Effects of pore size and surface charge on Na ion storage in carbon nanopores

Na ion batteries (NIBs) are considered as a promising low cost and sustainable energy storage technology.

Nitrogen-doped porous carbon materials: promising catalysts or catalyst supports for heterogeneous hydrogenation and oxidation

Developing novel and efficient catalysts is a critical step in common heterogeneous hydrogenation and oxidation reactions.

One-pot synthesis of sulfonated graphene oxide for efficient conversion of fructose into HMF

Sulfonated graphene oxide prepared through a one-pot method shows excellent catalytic performance for the dehydration of fructose into 5-hydroxymethylfurfural.

Potential prospects for carbon dots as a fluorescence sensing probe for metal ions

The well defined emission properties of CQDs have encouraged further investigation of their prospects in chemo-sensing applications for the identification of Cr³⁺ ions in aqueous media.

Biosourced, highly porous, carbon xerogel microspheres

The first tannin-based carbon xerogel microspheres were prepared and characterised.

A facile biomass based approach towards hierarchically porous nitrogen-doped carbon aerogels

Nitrogen-doped carbon aerogels with hierarchically porous architectures (NHCAs) are prepared via the hydrothermal treatment of cantaloupe and the following activation with potassium hydroxide.

Morphology evolution, formation mechanism and adsorption properties of hydrochars prepared by hydrothermal carbonization of corn stalk

Hydrochar spheres were formed by the condensation, polymerization and pyrolysis behavior of hemicellulose, amorphous cellulose and soluble lignin.

Mesoporous carbon derived from vitamin B12: a high-performance bifunctional catalyst for imine formation

Mesoporous carbon derived from natural vitamin B₁₂ is applied for the first time in organic synthesis and exhibits exceptionally high dual activity for imine formation via the cross-coupling of alcohols with amines and the self-coupling of primary amines.

Phase and morphology controlled in the synthesis of iron oxide particles: dimension-based carbonaceous materials as modifiers

Different phases and morphologies of iron oxide were selectively synthesized in the presence of different dimension carbonaceous materials as modifiers.

Cu(0) onto sulfonic acid functionalized silica/carbon composites as bifunctional heterogeneous catalysts for the synthesis of polysubstituted pyridines and nitriles under benign reaction media

Bifunctional heterogeneous catalysts based on Cu(0) onto sulphonated silica/carbon composites for the one-pot synthesis of polysubstituted pyridines and oxidative transformation of aldehydes to nitriles.

Activated mesoporous carbon nanofibers fabricated using water etching-assisted templating for high-performance electrochemical capacitors

Activated mesoporous carbon nanofibers are synthesized by a sequential process of electrospinning, water etching-assisted templating, and acid treatment, which exhibit outstanding capacitive performance.

Synthesis and characterization of porous carbon–MoS2 nanohybrid materials: electrocatalytic performance towards selected biomolecules

Porous carbon nanohybrids are promising materials as high-performance electrodes for both sensing and energy conversion applications.

Carbon Quantum Dots and Their Derivative 3D Porous Carbon Frameworks for Sodium-Ion Batteries with Ultralong Cycle Life

A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries.

Monodispersed Hollow SO3H-Functionalized Carbon/Silica as Efficient Solid Acid Catalyst for Esterification of Oleic Acid

SO3H-functionalized monodispersed hollow carbon/silica spheres (HS/C-SO3H) with primary mesopores were prepared with polystyrene as a template and p-toluenesulfonic acid (TsOH) as a carbon precursor and -SO3H source simultaneously. The physical and chemical properties of HS/C-SO3H were characterized by N2 adsorption, TEM, SEM, XPS, XRD, Raman spectrum, NH3-TPD, element analysis and acid-base titration techniques. As a solid acid catalyst, HS/C-SO3H shows excellent performance in the esterification of oleic acid with methanol, which is a crucial reaction in biodiesel production. The well-defined hollow architecture and enhanced active sites accessibility of HS/C-SO3H guarantee the highest catalytic performance compared with the catalysts prepared by activation of TsOH deposited on the ordered mesoporous silicas SBA-15 and MCM-41. At the optimized conditions, high conversion (96.9%) was achieved and no distinct activity drop was observed after 5 recycles. This synthesis strategy will provide a highly effective solid acid catalyst for green chemical processes.

Versatile Cellulose-Based Carbon Aerogel for the Removal of Both Cationic and Anionic Metal Contaminants from Water

Hydrothermal carbonization of cellulose in the presence of the globular protein ovalbumin leads to the formation of nitrogen-doped carbon aerogel with a fibrillar continuous carbon network. The protein plays here a double role: (i) a natural source of nitrogen functionalities (2.1 wt %) and (ii) structural directing agent (S(BET) = 38 m(2)/g). The applicability in wastewater treatment, namely, for heavy metal removal, was examined through adsorption of Cr(VI) and Pb(II) ion solely and in a mixed bicomponent aqueous solutions. This cellulose-based carbogel shows an enhanced ability to remove both Cr(VI) (∼68 mg/g) and Pb(II) (∼240 mg/g) from the targeted solutions in comparison to other carbon materials reported in the literature. The presence of competing ions showed little effect on the adsorption efficiency toward Cr(VI) and Pb(II).

Oxygen- and Nitrogen-Enriched 3D Porous Carbon for Supercapacitors of High Volumetric Capacity

Efficient utilization and broader commercialization of alternative energies (e.g., solar, wind, and geothermal) hinges on the performance and cost of energy storage and conversion systems. For now and in the foreseeable future, the combination of rechargeable batteries and electrochemical capacitors remains the most promising option for many energy storage applications. Porous carbonaceous materials have been widely used as an electrode for batteries and supercapacitors. To date, however, the highest specific capacitance of an electrochemical double layer capacitor is only ∼200 F/g, although a wide variety of synthetic approaches have been explored in creating optimized porous structures. Here, we report our findings in the synthesis of porous carbon through a simple, one-step process: direct carbonization of kelp in an NH3 atmosphere at 700 °C. The resulting oxygen- and nitrogen-enriched carbon has a three-dimensional structure with specific surface area greater than 1000 m(2)/g. When evaluated as an electrode for electrochemical double layer capacitors, the porous carbon structure demonstrated excellent volumetric capacitance (>360 F/cm(3)) with excellent cycling stability. This simple approach to low-cost carbonaceous materials with unique architecture and functionality could be a promising alternative to fabrication of porous carbon structures for many practical applications, including batteries and fuel cells.

Waste Tire Derived Carbon-Polymer Composite Paper as Pseudocapacitive Electrode with Long Cycle Life

Recycling hazardous wastes to produce value-added products is becoming essential for the sustainable progress of our society. Herein, highly porous carbon (1625 m(2)  g(-1)) is synthesized using waste tires as the precursor and used as a supercapacitor electrode material. The narrow pore-size distribution and high surface area led to good charge storage capacity, especially when used as a three-dimensional nanoscaffold to polymerize polyaniline (PANI). The composite paper was highly flexible, conductive, and exhibited a capacitance of 480 F g(-1) at 1 mV s(-1) with excellent capacitance retention of up to 98% after 10,000 charge/discharge cycles. The high capacitance and long cycle life were ascribed to the short diffusional paths, uniform PANI coating, and tight confinement of the PANI in the inner pores of the tire-derived carbon through π-π interactions, which minimized the degradation of the PANI upon cycling. We anticipate that the same strategy can be applied to deposit other pseudocapacitive materials to achieve even higher electrochemical performance and longer cycle life-a key challenge for redox active polymers.

3D Mesoporous Graphene: CVD Self-Assembly on Porous Oxide Templates and Applications in High-Stable Li-S Batteries

A nanostructured carbon with high specific surface area (SSA), tunable pore structure, superior electrical conductivity, mechanically robust framework, and high chemical stability is an important requirement for electrochemical energy storage. Porous graphene fabricated by chemical activation and liquid etching has a high surface area but very limited volume of electrochemically accessible mesopores. Herein, an effective strategy of in situ formation of hierarchically mesoporous oxide templates with small pores induced by Kirkendall diffusion and large pores attributed to evaporation of deliberately introduced volatile metal is proposed for chemical vapor deposition assembly of porous graphene frameworks (PGFs). The PGFs inherit the hierarchical mesoporous structure of the templates. A high SSA of 1448 m(2) g(-1), 91.6% of which is contributed by mesopores, and a mesopore volume of 2.40 cm(3) g(-1) are attained for PGFs serving as reservoirs of ions or active materials in electrochemical energy storage applications. When the PGFs are applied in lithium-sulfur batteries, a very high sulfur utilization of 71% and a very low fading rate of ≈0.04% per cycle after the second cycle are achieved at a current rate of 1.0 C. This work provides a general strategy for the rational construction of mesoporous structures induced by a volatile metal, with a view toward the design of hierarchical nanomaterials for advanced energy storage.

Direct Carbonization of Cyanopyridinium Crystalline Dicationic Salts into Nitrogen-Enriched Ultra-Microporous Carbons toward Excellent CO2 Adsorption

A family of nitrogen-enriched ultramicroporous carbon materials was prepared by direct carbonization of task-specifically designed molecular carbon precursors of cyanopyridinium-based crystalline dicationic salts (CISs). Varying the molecular structure of CISs, large surface area (918 m(2) g(-1)), high N content (20.10 wt %), and narrow distributed ultramicropores (0.59 nm) can be simultaneously achieved on the sample PCN-14 derived from methyl-linked 4-cyanopyridinium D[4-CNPyMe]Tf2N. It therefore exhibited exceptional performance in greenhouse gas CO2 capture, i.e., simultaneously possessing (1) high CO2 adsorption uptakes: 5.33 mmol g(-1) at 273 K, and 3.68 mmol g(-1) at 298 K (both at 1.0 bar); (2) unprecedented selectivity of CO2 versus N2: 156; and (3) a high adsorption ratio of CO2 to N2: 148 (at 1.0 bar). This is the first time such a high selectivity and adsorption ratio over carbon materials has been achieved, which is among the highest values over solid adsorbents.

Carbon-Based Sorbents with Three-Dimensional Architectures for Water Remediation

Over the past decade, carbon-based 3D architectures have received increasing attention in science and technology due to their fascinating properties, such as a large surface area, macroscopic bulky shape, and interconnected porous structures, enabling them to be one of the most promising materials for water remediation. This review summarizes the recent development in design, preparation, and applications of carbon-based 3D architectures derived from carbon nanotubes, graphene, biomass, or synthetic polymers for water treatment. After a brief introduction of these materials and their synthetic strategies, their applications in water treatment, such as the removal of oils/organics, ions, and dyes, are summarized. Finally, future perspective directions for this promising field are also discussed.

Conjugated microporous polymers with dimensionality-controlled heterostructures for green energy devices

Dimensionality for conjugated micro-porous polymers (CMP-nD, n = 0, 1, 2) is proven to be of great importance for tailoring their photophysical properties. Moreover, CMP-nD can further be converted into boron and nitrogen co-doped porous carbons (nDBN, n = 0, 1, 2) with maintained 0D, 1D, and 2D nano-structures and highly efficient catalytic performance.

Increased active sites and their accessibility of a N-doped carbon nanotube carbocatalyst with remarkably enhanced catalytic performance in direct dehydrogenation of ethylbenzene

This work presents a facile, low-cost, but efficient strategy for synthesizing HN-CNTs with enlarged active sites and their accessibility to reactants for the direct dehydrogenation of ethylbenzene.

Facile synthesis of mesoporous FeNi-alloyed carbonaceous microspheres as recyclable magnetic adsorbents for trichloroethylene removal

Magnetic separable porous FeNi/CS composites achieved through a one-pot hydrothermal carbonization method can reversibly adsorb TCE contaminant from wastewater.

An efficient low-temperature route to nitrogen-doping and activation of mesoporous carbons for CO2 capture

Nitrogen-doping of soft-templated mesoporous carbons is achieved at low temperatures (230–380 °C) and high yields (>90%) by using sodium amide.

Biological relevance of oxidative debris present in as-prepared graphene oxide

The influence of oxidative debris (OD) present in as-prepared graphene oxide (GO) suspensions on proteins and its toxicity to human embryonic kidney cells (HEK-293T) are reported here. The OD was removed by repeated washing with aqueous ammonia to produce the corresponding base-washed GO (bwGO). The loading (w/w) of bovine serum albumin (BSA) was increased by 85% after base washing, whereas the loading of hemoglobin (Hb) and lysozyme (Lyz), respectively, was decreased by 160% and 100%. The secondary structures of 13 different proteins bound to bwGO were compared with the corresponding proteins bound to GO using the UV circular dichroism spectroscopy. There was a consistent loss of protein secondary structure with bwGO when compared with proteins bound to GO, but no correlation between either the isoelectric point or hydrophobicity of the protein and the extent of structure loss was observed. All enzymes bound to bwGO and GO indicated significant activities, and a strong correlation between the enzymatic activity and the extent of structure retention was noted, regardless of the presence or absence of OD. At low loadings (<100 μg/mL) both GO and bwGO showed excellent cell viability but substantial cytotoxicity (~40% cell death) was observed at high loadings (>100 μg/mL). In control studies, OD by itself did not alter the growth rate even after a 48-h incubation. Thus, the presence of OD in GO played a very important role in controlling the chemical and biological nature of the protein-GO interface and the presence of OD in GO improved its biological compatibility when compared to bwGO.

Valorization of lignin waste from hydrothermal treatment of biomass: towards porous carbonaceous composites for continuous hydrogenation

Mineralized lignin obtained as the by-product of the hydrothermal digestion of rye straw with Ba(OH)₂ is used as precursor for the preparation of porous carbonaceous composites for catalytic hydrogenation applications.

Platinum functionalized multiwall carbon nanotube composites as recyclable catalyst for highly efficient asymmetric hydrogenation of methyl pyruvate

A highly efficient platinum nanoparticle functionalized carbon nanocomposite is demonstrated to be a recyclable heterogeneous catalyst for asymmetric hydrogenation of methyl pyruvate.

Biosourced graphitic nanoparticle loaded hyperbranched polyurethane composites – application as multifunctional high-performance coatings

Dynamic mechanical thermal analysis of GP-PU depicting a drastic increase in E′ and T_g with minuscule incorporation of GP-COOH.

N-doped porous carbon material made from fish-bones and its highly electrocatalytic performance in the oxygen reduction reaction

N-doped porous carbon material derived of fish bones showed excellent catalytic activity towards oxygen reduction reaction in alkaline medium, as well as long-term stability.

Recent advances in carbon nanospheres: synthetic routes and applications

Various strategies to carbon nanospheres together with a brief introduction of applications are presented in this feature article.

Electrochemical performance of hierarchical porous carbon materials obtained from the infiltration of lignin into zeolite templates

Hierarchical porous carbon materials prepared by the direct carbonization of lignin/zeolite mixtures and the subsequent basic etching of the inorganic template have been electrochemically characterized in acidic media. These lignin-based templated carbons have interesting surface chemistry features, such as a variety of surface oxygen groups and also pyridone and pyridinic groups, which results in a high capacitance enhancement compared to petroleum-pitch-based carbons obtained by the same procedure. Furthermore, they are easily electro-oxidized in a sulfuric acid electrolyte under positive polarization to produce a large amount of surface oxygen groups that boosts the pseudocapacitance. The lignin-based templated carbons showed a specific capacitance as high as 250 F g(-1) at 50 mA g(-1) , with a capacitance retention of 50 % and volumetric capacitance of 75 F cm(-3) at current densities higher than 20 A g(-1) thanks to their suitable porous texture. These results indicate the potential use of inexpensive biomass byproducts, such as lignin, as carbon precursors in the production of hierarchical carbon materials for electrodes in electrochemical capacitors.