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Cross-coupling reactions play a vital role in modern organic synthesis, enabling the construction of necessary C–C or C–(het)atom bonds for synthetic transformations. Although C(sp2)–C and C(sp2)–N cross-coupling reactions have received significant attention, recent advancements have also highlighted the significance of C(sp2)–S cross-coupling reactions. These reactions lead to the synthesis of valuable compounds, including pharmaceuticals and materials. In a recent report, we introduced Adaptive Dynamic Homogeneous Catalysis (AD-HoC) as an efficient method for C(sp2)–S cross-coupling reactions. This method operates without the need for any ligands, base, or additional additives, relying solely on essential parameters. In this report, we discuss the use of mesoporous graphitic carbon nitride (mpg-CN) as an all-organic heterogeneous photocatalyst in such transformations. The versatility and robustness of the reaction are showcased with fifty synthetic examples, achieving up to a 98% yield. The use of mpg-CN as a catalyst additionally enables the easy recovery of the photocatalyst from the reaction mixture and facilitates the sequential execution of multiple cross-coupling reactions with consistent yields of the desired products using a simple setup. This approach is a significant advancement in the field, both in terms of operational simplicity and environmental impact, traits that we all envision for sustainability. [ABSTRACT FROM AUTHOR]

This article reviews a variety of literature-reported lignin isolation procedures that bring partly minor but important changes in the produced extracts. Five lignins were produced or acquired from various sources and characterized based on their thermal properties, molecular weights, chemical structures, as well as elemental compositions, which were all found to depend on their extraction methods. These extracts were then used to produce 5 different nanolignins using 2 similar facile solvent shifting methods with the difference being an alteration in pH. The nanolignins were characterized after the solvent shifting accounting for differences in pH. Nanolignins generated via only solvent exchange exhibited diameters ranging from 58 nm to 95 nm, while nanolignins precipitated using a solvent shifting method along with a shift in pH exhibited diameters ranging from 10 nm to 34 nm and dissimilar morphology, size, and surface charge. Those differences highlight the control options for nanolignin preparetion on the colloidal length scale. Understanding how different lignins can be used to generate nanolignins is mandatory for unlocking the possibilities of nanolignin for functional material applications. These nanolignins can be applied in construction, medical, and/or agricultural industries as renewable, biodegradable alternatives to existing polymer dispersions. [ABSTRACT FROM AUTHOR]

We present the rational design of carbon/potassium poly(heptazine imide) (KPHI) heterostructures via one-step salt-melt assisted condensation for efficient photocatalysis. Hybridizing KPHI with an adenine-derived carbonaceous material (Ad-carbon) displayed an outstanding photocatalytic H2 evolution activity (738 μmol h−1 gcat−1; with 3 wt% Pt as the cocatalyst) and photocatalytic H2O2 production (3.94 mmol h−1 gcat−1). We establish that the Ad-carbon simultaneously operates as an electron acceptor and a photosensitizer based on structural, optical and photo(electro)chemical characterization. Building an intimate heterojunction between the Ad-carbon and KPHI induced spatial charge separation and prolonged the carrier lifetime. From electrocatalysis, we confirmed that coupling Ad-carbon with KPHI enhanced the surface reaction kinetics towards H2 evolution and O2 reduction reactions. Moreover, visual evidence of superior charge transport in the hybrid photocatalyst is revealed through the photodeposition of smaller Pt nanoparticles (∼7 nm) with uniform distribution on the carbon regions, which also accounts for the increased catalytic activity. [ABSTRACT FROM AUTHOR]

Recently, the missing link between homogeneous and heterogeneous catalysis has been found and it was named single-atom catalysis (SAC). However, the SAC field still faces important challenges, one of which is controlling the bonding/coordination between the single atoms and the support in order to compensate for the increase in surface energy when the particle size is reduced due to atomic dispersion. Excellent candidates to meet this requirement are carbon nitride (CN)-based materials. Metal atoms can be firmly trapped in nitrogen-rich coordination sites in CN materials, which makes them a unique class of hosts for preparing single-atom catalysts (SACs). As one of the most promising two-dimensional supports to stabilize isolated metal atoms, CN materials have been increasingly employed for preparing SACs. Herein, we will cover the most recent advances in single-atoms supported by CN materials. In this review, the most important characterization techniques and the challenges faced in this topic will be discussed, and the commonly employed synthetic methods will be delineated for different CN materials. Finally, the catalytic performance of SACs based on carbon nitrides will be reviewed with a special focus on their photocatalytic applications. In particular, we will prove CN as a non-innocent support. The relationship between single-atoms and carbon nitride supports is two-way, where the single-atoms can change the electronic properties of the CN support, while the electronic features of the CN matrix can tune the catalytic activity of the single sites in photocatalytic reactions. Finally, we highlight the frontiers in the field, including analytical method development, truly controlled synthetic methods, allowing the fine control of loading and multi-element synthesis, and how understanding the two-way exchange behind single-atoms and CN supports can push this topic to the next level. [ABSTRACT FROM AUTHOR]

Sustainable, high-performance carbonaceous anode materials are highly required to bring sodium-ion batteries to a more competitive level. Here, we exploit our expertise to control the deposition of a nm-sized conformal coating of carbon nitride with tunable thickness to improve the electrochemical performance of anode material derived from sodium lignosulfonate. In this way, we significantly enhanced the electrochemical performances of the electrode, such as the first cycle efficiency, rate-capability, and specific capacity. In particular, with a 10 nm homogeneous carbon nitride coating, the specific capacity is extended by more than 30% with respect to the bare carbon material with an extended plateau capacity, which we attribute to a heterojunction effect at the materials' interface. Eventually, the design of (inter)active electrochemical interfaces will be a key step to improve the performance of carbonaceous anodes with a negligible increase in the material weight. [ABSTRACT FROM AUTHOR]

Porous carbonaceous materials obtained from biomass have been an important class of CO2 sorbents since ancient times. Recent progress in carbon-based adsorbent technology is based on the implication of the concept of heteroatom doping. In this respect, the synthesis of carbonaceous materials through one-step condensation of cheap nitrogen-containing molecular precursors is an attractive strategy for obtaining such N-doped carbons. The design of the adsorbents obtained by this route relies on the careful adjustment of synthesis parameters, such as the temperature, the heating rate, and the atmosphere. However, in most cases, the latter choice remains rather empirical due to the lack of a fundamental understanding of the condensation mechanism of molecular precursors. In this work, we followed the structural, morphological, and chemical evolution of a molecular precursor (uric acid) at the nanoscale using a combination of in situ condensation inside a scanning transmission electron microscope with ex situ analysis of the products of condensation at different temperatures, atmospheres, and heating rates, and correlate our findings with the CO2 sorption properties of the obtained materials. We showed that varying pressures and reaction rates result in particles with different porosity. The porosity of the surface of the particles during the early stages of condensation governs the subsequent release of volatiles and the development of a hierarchical pore structure. We found that synthesis in vacuum enables effective condensation at considerably low temperatures (500 °C). Using a higher heating rate (10 °C min−1) suppresses structural ripening and preserves the optimal size of micropores, thus giving a CO2 uptake twice as high compared to samples synthesized in a nitrogen atmosphere, which is commonly used, preserving the same selectivity. [ABSTRACT FROM AUTHOR]

Herein, we report the use of reactive eutectic media from ammonium formate and monosaccharides to synthesize poly(hydroxyalkyl)pyrazines via microwave irradiation. This enabled unprecedented fast rates as well as better atom economy compared to previous methods. We investigated the influence of water on the reaction yield as well as the physical properties of the eutectic media and could thereby drastically reduce the viscosity, while preserving high reaction yields. The results were consistent for different monosaccharides, using fructose, glucose, rhamnose and fucose as reactants. Furthermore, the major reaction products were separated, chemically analyzed and tested for their antimicrobial activity via high-throughput screening. [ABSTRACT FROM AUTHOR]

The recent findings on the fundamental understanding of the activity of carbon nitride-based materials in the hydrogen evolution reaction (HER) allow to design rationally the photocatalytic systems with improved activities. Herein, combining highly ordered materials with cyanimide defects and alkali metal cations in the solution, we demonstrated an important synergistic effect which for cyanimide modified K-PHI is revealed in 12 times higher apparent quantum yield (AQY) compared to K-PHI free of surface cyanimide groups. [ABSTRACT FROM AUTHOR]

Here we report a photocatalytic system based on crystalline carbon nitrides (PHI) and highly dispersed transition metals (Fe, Co and Cu) for controlled methane photooxidation to methanol under mild conditions. The Cu-PHI catalyst showed a remarkable methanol production (2900 μmol g−1) in 4 hours, with a turnover number of 51 moles of oxygenated liquid product per mole of Cu. To date, this result is the highest value for methane oxidation under mild conditions (1 bar, 25 °C). [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) that for instance takes place at the cathode of fuel cells is one of the most examined model reactions of energy conversion. The ORR presents sluggish reaction kinetics, thus limiting the overall efficiency of these cells. Pt-based catalysts are still the widest choice though they exhibit important drawbacks such as long-term instability and intolerance to methanol crossover. In this context, engineering transition metals in the form of nano- and subnano-sites on carbonaceous supports has the potential of becoming an alternative to scarce noble metal-based catalysts. Herein, we describe a simple synthetic route towards CuII/CuI decorated N-doped carbonaceous ORR electrocatalysts. CuII/CuI nanosites are obtained by calcination in air of an ionic liquid derived noble carbonaceous support impregnated with copper(II) acetate. The strong interaction between the copper and the noble support foster the co-formation of CuII/CuI nanosites. Larger amounts of copper(II) acetate translate into larger amounts of CuI and lower Tafel slopes. The material with 4 wt% of copper catalyzes the selective reduction of oxygen through a 4-electron transfer pathway and exhibits a lower Tafel slope than commercial platinum, a minimal overpotential, and a higher limiting current density. Moreover, all materials show promising durability and high methanol stability, which makes them promising to replace noble metals for the ORR. [ABSTRACT FROM AUTHOR]

Photocatalytic H2 production via water splitting holds great potential for the conversion of solar energy into renewable and storable chemical fuels in a sustainable manner, but this up-hill reaction is mainly hindered by the water oxidation process. This reaction is sluggish and relies on high overpotentials (wasted energy), while only oxygen is generated as a low value oxidation by-product. Coupling hydrogen generation to a less unfavorable oxidation reaction creating higher value products is therefore a recommendable issue. Here we found that poly(heptazine imide) (PHI), a stable and reactive allotrope of crystalline carbon nitride, supported with highly dispersed Pt nanoparticles (PtNPs) could achieve efficient and persistent H2 and CH4 production by photocatalytic reforming of biomass derived alcohols under visible light irradiation. The results reveal that PHI with low grain boundary defects restrains the bulk charge carrier recombination and largely promotes photocatalytic efficiency. The apparent quantum efficiency (AQE) of the optimized material for visible light H2 evolution could reach values as high as 15% at 420 nm. The DFT results reveal that the activity is associated with the Tafel step rather than the Volmer–Tafel step. This study highlights the development of a new covalent scaffold for the simultaneous generation of storable and valuable chemical fuels (H2 and CH4) in a feasible photocatalytic manner. [ABSTRACT FROM AUTHOR]

Sodium lignosulfonate (LS) was valorized to low molecular weight (Mw) fractions by combining solvothermal (SF) and catalytic hydrogenolysis/hydrogenation fragmentation (SHF) in a continuous flow system. This was achieved in either alcohol/H2O (EtOH/H2O or MeOH/H2O) or H2O as a solvent and Ni on nitrogen-doped carbon as a catalyst. The tunability according to the temperature of both SF and catalytic SHF of LS has been separately investigated at 150 °C, 200 °C, and 250 °C. In SF, the minimal Mw was 2994 g mol−1 at 250 °C with a dispersity (Đ) of 5.3 using MeOH/H2O. In catalytic SHF using MeOH/H2O, extremely low Mw was found (433 mg gLS−1) with a Đ of 1.2 combined with 34 mg gLS−1. The monomer yield was improved to 42 mg gLS−1 using dual catalytic beds. These results provide direct evidence that lignin is an unstable polymer at elevated temperatures and could be efficiently deconstructed under hydrothermal conditions with and without a catalyst. [ABSTRACT FROM AUTHOR]

The interaction between water molecules and surfaces in porous systems is of huge importance in various fields including but not limited to catalysis, adsorption, and the storage or conversion of electrochemical energy. Hydrophilicity of usually non-polar carbon-based materials can be enhanced by the incorporation of heteroatoms like nitrogen but insights into the interaction mechanisms on a molecular level remain hardly achievable due to the lack of porous carbons with a defined and regular atomic construction and a suitable structure model for such substances. This makes theoretical calculations difficult. In order to illuminate the interactions between nitrogen-containing carbon surfaces and water molecules, water adsorption is studied in this work on a series of model materials with different pore structures and atomic construction. In particular, volumetric adsorption measurements and 1H solid-state NMR spectroscopic investigations in combination with theoretical calculations on water in nitrogen-rich C2N materials show a remarkably strong heat of adsorption significantly above 60 kJ mol−1, that is, far beyond what is typically considered physisorption. In such porous materials, water is becoming an integral part of the chemical architecture, and the term "zeocarbons" is therefore well deserved. From a general perspective, this study is intended to set a base for establishing the chemical principles of a new water chemistry confined in strongly interacting nanopores. [ABSTRACT FROM AUTHOR]

The chemistry of humic substances (HSs) occurs hidden from our sight, but is of key importance to agriculture and the environment, and nowadays even to medicine and technology. HSs are nowadays not only natural, but extracted and engineered, and in the past 20 years such products have been widely used in soil improvement and environment governance. In this review, we collate and summarize the applications and working principles of such HSs in agriculture and environmental ecology, mainly to elaborate the multiple roles of this functional polymer along with physical chemical quantification. Then several of the latest synthesis technologies, including hydrothermal humification technology (HTH), hydrothermal carbonization technology (HTC) and hydrogen peroxide oxidation technology (HOT) are presented, which were introduced to prepare artificial humic substances (A-HSs). The availability of reproducible and tunable synthetic A-HSs is a new chemical tool, and effects such as solubilization of insoluble phosphorus minerals, recovery of phosphorus, improvement of soil fertility for crop growth and reduction of toxicity of typical pollutants, can now be analyzed in detail and quantified. As a result, we can provide an effective chemical technology for utilizing biomass side products ("biowaste") to generate A-HSs of different types, thus realizing improvement in agricultural production and control of environmental pollution by the macro-synthesis of A-HSs-. [ABSTRACT FROM AUTHOR]

To render the sodium ion battery (SIB) competitive among other technologies, the processes behind sodium storage in hard carbon anodes must be understood. For this purpose, electrochemical impedance spectroscopy (EIS) is usually undervalued, since fitting the spectra with equivalent circuit models requires an a priori knowledge about the system at hand. The analysis of the distribution of relaxation times (DRT) is an alternative, which refrains from fitting arbitrarily nested equivalent circuits. In this paper, the sodiation and desodiation of a hard carbon anode is studied by EIS at different states of charge (SOC). By reconstructing the DRT function, highly resolved information on the number and relative contribution of individual electrochemical processes is derived. During the sloping part of the sodiation curve, mass transport is found to be the most dominant source of resistance but rapidly diminishes when the plateau phase is reached. An equivalent circuit model qualitatively reproducing the experimental data of the sloping region was built upon the DRT results, which is particularly useful for future EIS studies on hard carbon SIB anodes. More importantly, this work contributes to establish EIS as a practical tool to directly study electrode processes without the bias of a previously assumed model. [ABSTRACT FROM AUTHOR]

A novel method based on the use of reactive eutectic media for the extraction of cellulose nanocrystals and their functionalization with positively charged functional groups in a one-step procedure is presented. With its ability to form strong hydrogen bonds, the eutectic medium serves as a cellulose-solubilizing agent, while the presence of a Leuckart reagent provides the reactivity toward the reductive amination of carbonyl groups in the cellulose chains. In the proposed method, amorphous cellulose domains are partially dissolved by undergoing aminolysis, resulting in the formation of water-dispersible nanocellulose products with high crystallinity. [ABSTRACT FROM AUTHOR]

We report the synthesis of 1,4-dicarbonyl compounds and substituted alkenes (Mizoroki–Heck type coupling) starting from secondary and tertiary alkyl halides and vinyl acetate or styrene derivatives using visible-light photocatalysis. The protocol uses mesoporous graphitic carbon nitride (mpg-CN) as a heterogeneous organic semiconductor photocatalyst and Ni(II) salts as Lewis acid catalysts. Detailed post-characterization of the heterogeneous material has been carried out to support the proposed catalytic cycle. Apart from high functional-group tolerance, mild reaction conditions, scalability as well as easy recovery and reuse of the mpg-CN photocatalyst provide a practical solution to these widespread transformations in terms of sustainability and efficiency and this methodology is recommended for applications in academic and industrial synthesis. [ABSTRACT FROM AUTHOR]

A network of aqueous emulsion droplets that exhibits programmed and directional chemical inter-droplet communication is described. A non-reciprocal transfer of substrates between enzyme-containing aqueous emulsion droplets is realized by (biochemically) induced osmolarity gradients and concomitant concentration gradients are used to direct a multistep enzymatic cascade reaction across multiple droplets. [ABSTRACT FROM AUTHOR]

The synthesis of sp2-conjugated, heteroatom-rich, "carbonaceous" materials from economically feasible raw materials and salt templates is reported. Low cost citrazinic acid (2,6-dihydroxy-4-pyridinecarboxylic acid) and melamine are used as components to form a microporous, amorphous framework, where edges of the covalent frameworks are tightly terminated with nitrogen and oxygen moieties. ZnCl2 as the porogen stabilizes structural microporosity as well as nitrogen and oxygen heteroatoms up to comparably high condensation temperatures of 750 and 950 °C. The specific surface area up to 1265 m2 g−1 is mainly caused by micropores and typical of heteroatom-rich carbon materials with such structural porosity. The unusually high heteroatom content reveals that the edges and pores of the covalent structures are tightly lined with heteroatoms, while C–C or C–H bonds are expected to have a minor contribution as compared to typical carbon materials without or with minor content of heteroatoms. Adsorption of water vapor and carbon dioxide are exemplarily chosen to illustrate the impact of this heteroatom functionalization under salt-templating conditions on the adsorption properties of the materials. 27.10 mmol g−1 of H2O uptake (at p/p0 = 0.9) can be achieved, which also proves the very hydrophilic character of the pore walls, while the maximum CO2 uptake (at 273 K) is 5.3 mmol g−1. At the same time the CO2/N2 adsorption selectivity at 273 K can reach values of up to 60. All these values are beyond those of ordinary high surface area carbons, also differ from those of N-doped carbons, and are much closer to those of organized framework species, such as C2N. [ABSTRACT FROM AUTHOR]

The continuous flow synthesis of p-xylene (pXL) via Diels–Alder cycloaddition of lignocellulosic biomass-derivable 2,5-dimethylfuran (DMF) and acrylic acid (AA) was performed over different type of zeolites, i.e. Beta, ZSM-5 and Y. Among the tested zeolites, Beta zeolite showed an optimum catalytic performance in pXL synthesis from DMF and AA. In this context, Beta zeolite with a Si/Al molar ratio of 150 which is abbreviated as Beta(150), resulted in complete DMF conversion with a pXL yield of 83% and by-product 2,5-dimethylbenzoic acid (DMBA) with a yield of 17%, at 473 K in 10.1 min residence time (τ), with excess AA (0.7 M). This high catalytic activity is attributed to the high specific surface area of 1180 m2 g−1 with a three-dimensional porous architecture with a pore diameter of 6.6 × 6.7 Å and an acid site density above 40 μmol g−1. The utilized Beta(150) showed a very stable performance up to 10 h time on stream with minor deactivation after 8 h of TOS, while the pXL yield remained above 70%. The original catalytic performance of Beta(150) in the conversion of DMF to pXL was restored by applying a regeneration step for the spent catalyst, which is simple in continuous flow reactors. Finally, this sustainable continuous flow process enables an efficient and selective pXL production from DMF and AA as a dienophile at lower reaction temperature (473 K) and shorter residence time (τ = 10.1 min) in comparison to a batch fashion. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO2 provides a way to generate base chemicals from an abundant C1-source under mild conditions, whilst at the same time mitigating CO2 emissions. In this work, a novel class of tailorable, porous electrocatalysts for this process is proposed. Covalent triazine frameworks (CTFs) are grown in situ onto functionalized multiwalled carbon nanotubes. Hydroxyl groups decorating the surface of the multiwalled carbon nanotubes facilitate intimate contact between the carbon nanotubes and CTF, thus promoting efficient electron transfer. The novel hybrid materials generate CO with a faradaic efficiency up to 81% at an overpotential of 380 mV. The selectivity of the electrocatalysts could be linked to the amount of nitrogen present within the framework. [ABSTRACT FROM AUTHOR]

Hydrogenation reactions in water at elevated temperatures are challenging for heterogeneous catalysts. Thus, we present a simple, cheap, scalable, and sustainable approach for synthesizing an efficient and stable Ni catalyst supported on highly porous nitrogen-doped carbon (NDC) in pellet form. The performance of this catalyst was evaluated in the aqueous-phase hydrogenation of lignocellulosic biomass-derived compounds, i.e., glucose (Glu), xylose (Xyl), and vanillin (V), using a continuous-flow system. The as-prepared 35 wt% Ni on NDC catalyst exhibited a high catalytic performance in all three aqueous-phase hydrogenation reactions, i.e., the conversion of Glu, Xyl, and V was 96.3 mol%, 85 mol%, and 100 mol% and the yield of sorbitol (Sor), xylitol (Xyt), and 2-methoxy-4-methylphenol (MMP) was 82 mol%, 62 mol%, and 100 mol%, respectively. This high activity was attributed to the high specific surface area of NDC and mainly to the heterojunction effects stabilizing and adjusting the homogenously and highly dispersed Ni nanoparticles (ANi = 20 m2 g−1) on the surface of NDC. Changing the electron density in the nickel nanoparticles allows the high performance of the catalyst for a long time on stream (40 h) with minimized Ni leaching and without the loss in catalytic performance. [ABSTRACT FROM AUTHOR]

Tinted long-lived ionic carbon nitride radicals were recently introduced and applied in photocatalysis and energy storage. However, the reason for their higher activity in the photocatalytic reaction and optimal conditions for generating such radicals remain vague. Herein, we study the conditions for carbon nitride photocharging to achieve a higher charge density and validate a convenient method to quantify the number of electrons accumulated in carbon nitride semiconductors by quenching its radicals with methylviologen in the dark. In the presence of CO2, potassium poly(heptazine imide) (K-PHI) can be charged by up to 1000 μmol of electrons per gram of the material using benzylamine as an electron donor. Under the same conditions, mesoporous graphitic carbon nitride can accumulate only 50 μmol of electrons per gram. The products of the benzylamine oxidative coupling are imine and ammonia. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new approach for valorization of monosaccharides derived from biomass into value added chemicals in a green and economically efficient manner by forming eutectic medium exclusively between reactants. Eutectic mixtures are emerging as an advantageous alternative to ionic liquids and have already found broad applications in biomass treatment; however they are preferably used only as low vapor pressure solvents. Increasing interest in eutectic solvents originates from their flexibility to adjust their properties to different biorefinery needs by simple variation of the compositions of eutectic mixtures. In this work, we made a first attempt to use a low molecular weight component, ammonium formate, to significantly change the physical properties of the eutectic mixtures and simultaneously increase their chemical reactivity. Using this approach, we valorised simple monosaccharides by turning them into fructopyrazines with high yields in their eutectic mixtures with ammonium formate. The research revealed a high sensitivity of the product yields to the temperature of the reaction and composition of the eutectic medium, as well as an important role of formate anions in product stabilization. [ABSTRACT FROM AUTHOR]

Gallic acid and urea are used to produce C2NO materials with moderately defined micropores via direct condensation and ring closure. These materials show a unique heterocycle containing carbonaceous structure and feature an unusually high content of heteroatoms (nitrogen and oxygen) lining the insides of pores while having high specific surface areas. The multifunctional carbon materials demonstrate good performance for selective CO2 capture resulting from adjustable porosity and polarizability. In view of the simplicity of the salt flux synthetic method and the advantage of the available sustainable starting synthons, the C2NO framework has potential for use in diverse practical applications. [ABSTRACT FROM AUTHOR]

A nanoporous material bearing a high ion density and inherent organic radical character was synthesized by a facile one-pot process, which exhibits photo-, piezo- and chemochromism, driven by the diverse electron transfer processes between the acceptor framework and different electron donors. The responsive behavior is useful for its sensing application, as demonstrated here for pressure, anion and gas sensing. [ABSTRACT FROM AUTHOR]

Modification of the C2 position of the standard 1-butyl-3-methyl imidazolium cation by a borohydride group leads to a zwitterionic liquid (ZIL). The resulting imidazol-2-ylidene borane ZIL is liquid at room temperature. Dynamic viscosity as well as thermal and electrochemical stability are investigated. Thermal decomposition follows a similar pathway as in comparable imidazolium ionic liquids. The surprisingly low viscosity and good reductive stability make it a promising candidate for electrochemical applications. [ABSTRACT FROM AUTHOR]

A series of materials are prepared by supramolecular preorganization of melamine and chloranilic acid and thermal polycondensation. Via the introduction of halogen substitution, the morphology of the supramolecular assembly was successfully altered from 2D plates to 1D nanofibers. The H-bridged crystals are organic semiconductors as such, which however can be massively activated by surface polymerization to create “boxed semiconductors” where the surface layer forms active loci for charge separation and transfer. The resulting polymer coated crystals show high photooxidation potential, as exemplified by Rhodamine B (RhB) degradation, as well as being able to liberate oxygen from water under visible light illumination. The box structure is maintained throughout further thermal condensation, and hollow 1d carbon tubes are obtained at 800 °C. [ABSTRACT FROM AUTHOR]

Triazoles have been successfully used as building blocks to create “fully organic” ILs featuring on both sides organic ions, i.e., 1,2,3- or 1,2,4-triazolide anions and 1,2,4-triazolium or imidazolium cations. Glass transition temperatures, densities and viscosities of these ILs were determined. Their electrochemical and thermal stability, and also conductivity, are higher than those for known ILs. [ABSTRACT FROM AUTHOR]

The abundant carbohydrate fructose is converted into two biofuel molecules, namely 2,5-dimethylfuran (DMF) and ethyl levulinate (EL) in a simple cascade flow reactor. With an overall yield of 85% (38.5% of 2,5-dimethylfuran and 47% of ethyl levulinate), the main remainder is unconverted fructose. The two column flow reactor set-up enables the adjustment of temperatures and reaction times in such a way that the reactive intermediate hydroxymethylfurfural (5-HMF) is generated in optimal yields and converted into the stable DMF immediately. The process is so simple and fast (＜20 min) that economic and sustainable production of these fuels and platform chemicals can be envisioned. A remaining minor char formation is regarded to be the major problem which has to be addressed by catalyst development. [ABSTRACT FROM AUTHOR]

Via utilizing a phenomenon that is usually observed in the food industry, a scalable, safe, and cheap synthesis method for processable and functional porous carbons has been presented. Using simple sugars in combination with urea, low melting liquids can be formed that are also stable at room temperature without recrystallization. Due to low vapor pressure, these melts can be easily stored and handled for further use as carbon precursors. The resulting carbon materials possess high nitrogen content and are obtained in high yield. The liquid precursor state also allows the addition of further substances, and highly porous carbon monoliths can be formed by the introduction of a salt/fiber mixture. Herein, cellulose was found to serve as an efficient additive, which resulted in processable viscoelastic doughs without the alteration of the final carbon properties. This method is of special importance with regard to industrial processes as compared to standard carbonization, and it becomes possible to handle intermediates in a green body fashion. Eventually, compared to pre-baked bread rolls, storable intermediates can be processed which inherently contain already all the final carbon properties. The carbon cookies were stable against oxidation and were shown to be highly suitable as a sorption material, which was demonstrated via dye-removal from an aqueous solution. [ABSTRACT FROM AUTHOR]

A hierarchically porous carbon monolith with a density of 0.059 g cm−3 (97% porosity) was generated through the carbonization of an emulsion-templated monolith formed from a deep-eutectic polymer based on the polycondensation of 2,5-dihydroxy-1,4-benzoquinone with excess urea. The mechanical integrity and thermal stability of the monolith were successfully enhanced through a chain extension reaction with terephthaloyl chloride (TCL) that occurred during/following the formation of a high internal phase emulsion (HIPE). The bimodal, open-cell macroporous structure of the monolith consisted of many smaller voids with an average diameter of 15 μm and some larger voids with an average diameter of 49 μm. Carbonization of the monolith introduced microporosity and meso/macro-porosity, yielding a high specific surface area (812 m2 g−1, largely from micropores), a micropore volume of 0.266 cm3 g−1 (an average diameter of 0.67 nm), and a meso/macro-pore volume of 0.238 cm3 g−1 (an average diameter of 8.1 nm). The elemental composition of the chain-extended polymeric monolith was similar to that predicted from the HIPE components except for a relatively low nitrogen content which may indicate the loss of some urea groups during the chain extension reaction with TCL. The nitrogen–carbon bonds in the carbon monolith from the chain-extended polymer were around 47% pyridinic, 20% pyrrolic, and 33% graphitic. While chain-extension reduced the nitrogen content, the mechanical integrity and thermal stability were enhanced, which was key to generating a highly microporous carbon monolith with a hierarchical porous structure. The carbon monolith exhibited promising results for aqueous solution sorption applications, in both batch and flow modes, owing to its advantageous combination of properties. [ABSTRACT FROM AUTHOR]

Functional porous carbon nanospheres with tunable textural properties and nitrogen functionalities were synthesized from a cheap and sustainable phenolic carbon precursor (tannic acid) and nitrogen precursor (urea) using a facile one-step salt-templating method. The diverse functional carbons were obtained by calcination of mixtures of different molar ratios of urea to tannic acid (0 : 1, 5 : 1, 9 : 1, 13 : 1 and 17 : 1) with a eutectic salt (NaCl/ZnCl2) that was used as the porogen. The physico-chemical characterization of the obtained microporous carbons demonstrated that the textural properties, morphology, surface functionalities, and conductivity were strongly influenced by the molar ratio of urea to tannic acid. The nitrogen content in the carbons increased with the molar ratio of urea, reaching a maximum of 8.83% N at the highest molar ratio while the specific surface area (SBET) of the microporous carbons varied from 890 m2 g−1 to 1570 m2 g−1 depending on the synthesis conditions. The electrochemical performance of the carbon nanospheres in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) was also significantly influenced by the synthesis conditions due to the combined effect of textural properties, morphology, nitrogen functionalities and electrical conductivity. Supercapacitors based on the functional porous carbon synthesized with a molar ratio of urea to tannic acid of 9 : 1 exhibited the best performance, with a specific capacitance as high as 110 F g−1 and a real energy density of 33 W h kg−1, when charged–discharged at 3.5 V in PYR14FSI. [ABSTRACT FROM AUTHOR]