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Copper (Cu)‐based catalysts have established their unique capability for yielding wide value‐added products from CO2. Herein, we demonstrate that the pathways of the electrocatalytic CO2 reduction reaction (CO2RR) can be rationally altered toward C1 or C2+ products by simply optimizing the coordination of Cu with O‐containing organic species (squaric acid (H2C4O4) and cyclohexanehexaone (C6O6)). It is revealed that the strength of Cu−O bonds can significantly affect the morphologies and electronic structures of derived Cu catalysts, resulting in the distinct behaviors during CO2RR. Specifically, the C6O6−Cu catalysts made up from organized nanodomains shows a dominant C1 pathway with a total Faradaic efficiency (FE) of 63.7 % at −0.6 V (versus reversible hydrogen electrode, RHE). In comparison, the C4O4−Cu with an about perfect crystalline structure results in uniformly dispersed Cu‐atoms, showing a notable FE of 65.8 % for C2+ products with enhanced capability of C−C coupling. The latter system also shows stable operation over at least 10 h with a high current density of 205.1 mA cm−2 at −1.0 VRHE, i.e. is already at the boarder of practical relevance. This study sheds light on the rational design of Cu‐based catalysts for directing the CO2RR reaction pathway. [ABSTRACT FROM AUTHOR]

Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen‐containing molecules. Here, we report the sustainable production of amino acids from biomass‐derived hydroxy acids with high activity under visible‐light irradiation and mild conditions, using atomic ruthenium‐promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0 molAla ⋅ gRu−1 ⋅ h−1, which is 1.7 times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O−H bond dissociation of the α‐hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH−OH and CH3−CH−OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine. [ABSTRACT FROM AUTHOR]

Solar‐driven photocatalysis employing particulate semiconductors represents a promising approach for sustainable production of valuable chemical feedstock. Metal poly(heptazine imide) (MPHI), a novel 2D ionic carbon nitride, has been recognized as an emerging photocatalyst with distinctive properties. In this minireview, we first delineate the forefront innovations of MPHI photocatalysts, spanning from synthetic strategies and solving structures to the exploration of novel properties. We place special emphasis on the structural design principles aimed at developing high‐performance MPHI systems toward photocatalytic solar fuel production such as H2 evolution, H2O oxidation, H2O2 production and CO2 reduction. Finally, we discuss crucial insights and challenges in leveraging highly active MPHIs for efficient solar‐to‐chemical energy conversion. [ABSTRACT FROM AUTHOR]

According to the principles of chemical thermodynamics, the catalytic activation of small molecules (like N2 in air and CO2 in flue gas) generally exhibits a negative activity dependence on O2 owning to the competitive oxygen reduction reaction (ORR). Nevertheless, some catalysts can show positive activity dependence for N2 electrofixation, an important route to produce ammonia under ambient condition. Here we report that the positive activity dependence on O2 of (Ni0.20Co0.20Fe0.20Mn0.19Mo0.21)3S4 catalyst arises from high‐entropy mechanism. Through experimental and theoretical studies, we demonstrate that under the reaction condition in the mixed N2/O2, the adsorption of O2 on high‐entropy catalyst contributes to activating N2 molecules characteristic of elongated N≡N bond lengths. As comparison to the low‐ and medium‐entropy counterparts, high entropy can play the second role of attenuating competitive ORR by displaying a negative exponential entropy‐ORR activity relationship. Accordingly, benefiting from the O2, the system for direct air electrofixation has demonstrated an ammonia yield rate of 47.70 μg h−1 cm−2, which is even 1.5 times of pure N2 feedstock (31.92 μg h−1 cm−2), overtaking all previous reports for this reaction. We expect the present finding providing an additional dimension to high entropy that leverages systems beyond the constraint of traditional rules. [ABSTRACT FROM AUTHOR]

Redox flow batteries have been discussed as scalable and simple stationary energy storage devices. However, currently developed systems encounter less competitive energy density and high costs, restricting their wider application. There is a lack of appropriate redox chemistry, preferably based on active materials that are abundant in nature and show high solubility in aqueous electrolytes. A nitrogen‐centered redox cycle operating between the limiting species ammonia and nitrate via an eight‐electron redox reaction stayed practically unnoticed, albeit its ubiquity in biological processes. Ammonia or nitrate are world‐scale chemicals with high aqueous solubility, and are then comparably safe. We demonstrate here the successful implementation of such a nitrogen‐based redox cycle between ammonia and nitrate with eight‐electron transfer as a catholyte for Zn‐based flow batteries, which continuously worked for 12.9 days with 930 charging‐discharging cycles. A very competitive energy density of 577 Wh L−1 can be reached, which is well above most reported flow batteries (e.g. 8 times the standard Zn‐bromide battery), demonstrating that the nitrogen cycle with eight‐electron transfer can offer promising cathodic redox chemistry for safe, affordable, and scalable high‐energy‐density storage devices. [ABSTRACT FROM AUTHOR]

Self‐templating is a facile strategy for synthesizing porous carbons by direct pyrolysis of organic metal salts. However, the method typically suffers from low yields (<4%) and limited specific surface areas (SSA<2000 m2 g−1) originating from low activity of metal cations (e.g. K+ or Na+) in promoting construction and activation of carbon frameworks. Here we use cesium acetate as the only precursor of oxo‐carbons with large SSA of the order of 3000 m2 g−1, pore volume approaching 2 cm3 g−1, tunable oxygen contents, and yields of up to 15 %. We unravel the role of Cs+ as an efficient promoter of framework formation, templating and etching agent, while acetates act as carbon/oxygen sources of carbonaceous frameworks. The oxo‐carbons show record‐high CO2 uptake of 8.71 mmol g−1 and an ultimate specific capacitance of 313 F g−1 in the supercapacitor. This study helps to understand and rationally tailor the materials design by a still rare organic solid‐state chemistry. [ABSTRACT FROM AUTHOR]

The aqueous electrocatalytic reduction of NO3− into NH3 (NitrRR) presents a sustainable route applicable to NH3 production and potentially energy storage. However, the NitrRR involves a directly eight‐electron transfer process generally required a large overpotential (<−0.2 V versus reversible hydrogen electrode (vs. RHE)) to reach optimal efficiency. Here, inspired by biological nitrate respiration, the NitrRR was separated into two stages along a [2+6]‐electron pathway to alleviate the kinetic barrier. The system employed a Cu nanowire catalyst produces NO2− and NH3 with current efficiencies of 91.5 % and 100 %, respectively at lower overpotentials (>+0.1 vs. RHE). The high efficiency for such a reduction process was further explored in a zinc‐nitrate battery. This battery could be specified by a high output voltage of 0.70 V, an average energy density of 566.7 Wh L−1 at 10 mA cm−2 and a power density of 14.1 mW cm−2, which is well beyond all previously reported similar concepts. [ABSTRACT FROM AUTHOR]

The influence of structural modifications on the catalytic activity of carbon materials is poorly understood. A collection of carbonaceous materials with different pore networks and high nitrogen content was characterized and used to catalyze four reactions to deduce structure–activity relationships. The CO2 cycloaddition and Knoevenagel reaction depend on Lewis basic sites (electron‐rich nitrogen species). The absence of large conjugated carbon domains resulting from the introduction of large amounts of nitrogen in the carbon network is responsible for poor redox activity, as observed through the catalytic reduction of nitrobenzene with hydrazine and the catalytic oxidation of 3,3′,5,5′‐tetramethylbenzidine using hydroperoxide. The material with the highest activity towards Lewis acid catalysis (in the hydrolysis of (dimethoxymethyl)benzene to benzaldehyde) is the most effective for small molecule activation and presents the highest concentration of electron‐poor nitrogen species. [ABSTRACT FROM AUTHOR]

The electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H2O2 synthesis, where a structure–selectivity relationship is pivotal for the control of a highly selective and active two‐electron pathway. Here, we report the fabrication of a boron and nitrogen co‐doped turbostratic carbon catalyst with tunable B−N−C configurations (CNB‐ZIL) by the assistance of a zwitterionic liquid (ZIL) for electrochemical hydrogen peroxide production. Combined spectroscopic analysis reveals a fine tailored B−N moiety in CNB‐ZIL, where interfacial B−N species in a homogeneous distribution tend to segregate into hexagonal boron nitride domains at higher pyrolysis temperatures. Based on the experimental observations, a correlation between the interfacial B−N moieties and HO2− selectivity is established. The CNB‐ZIL electrocatalysts with optimal interfacial B−N moieties exhibit a high HO2− selectivity with small overpotentials in alkaline media, giving a HO2− yield of ≈1787 mmol gcatalyst−1 h−1 at −1.4 V in a flow‐cell reactor. [ABSTRACT FROM AUTHOR]

Direct synthesis of N‐containing organic compounds from dinitrogen (N2) can make synthetic chemistry more sustainable. Previous bottlenecks in lithium‐mediated N2 fixation were resolved by loading Li‐metal anodes covered with the typical Li+ ion‐conducting solid electrolyte interface, which are subsequently allowed to react with N2. The developed strategy allowed us to reach high Faradaic efficiencies toward Li3N. These reactive Li3N were then contacted with acylchlorides. Surface nitride ions are more nucleophilic than amines which direct the two C−N coupling reactions toward formation of imides rather than amides, and an integrated current efficiency of 57–77 % could be realized. This study thereby not only provides a feasible electrochemical Li3N synthesis, but also delineates an economical and green synthesis of highly valuable N‐containing compounds from N2 under mild conditions, just using commercial spare parts and processes from the omnipresent Li battery technology. [ABSTRACT FROM AUTHOR]

It has been long believed that the FeMoS structure, where Fe is bonded with S, plays a pivotal role as a biomimetic catalyst for electrochemical nitrogen (N2) fixation. Nevertheless, the structure of Fe bonded to heavier analogues (Se or Te) has never been explored for N2 electrofixation. Here, we theoretically predict the electronic structure of FeMo(Se, Te) composed of tri‐coordinated Fe species with open shells for binding with Se, which forms a joint electron pool for promoting N2 activation. Guided by this interesting prediction, we then demonstrate a two‐step procedure to synthesize such structures, which display remarkable N2 electrofixation activities with an ammonia yield of 72.54 μg h−1 mg−1 and a Faradic efficiency of 51.67 % that are more than three times of the FeMoS counterpart. Further mechanism studies have been conducted by density function theory (DFT) simulations. This work provides new clues for designing versatile electrocatalytic materials for large‐scale industrialization. [ABSTRACT FROM AUTHOR]

We designed a metal‐free synthesis of carbon nanofiber based on ketene chemistry using phosphorus pentoxide (P2O5) and vegetable oil. Based on the characterization of intermediates, P2O5‐oil reaction yielded most possibly alkylketenes, which polymerized into poly(ketene) with abundant enol groups. The enol groups further reacted with P2O5, forcing the poly(ketene) to assemble into a nano‐sized preassembly structure. Moderate heating transforms these structures into carbonaceaus nanofibers. This approach is applicable to other chemicals with similar structure to vegetable oil. The carbon nanofibers with P‐O‐C functionalization show relatively high graphitization degree and promising textural properties. The C‐O‐P environment accounts for 66 at % of the total P and creates a superior thermal stability. As a model application, a CDI system built of a carbon‐nanofiber‐based electrode countered by an activated carbon‐based electrode exhibited exceptional performance. [ABSTRACT FROM AUTHOR]

The hydrosilylation reaction is one of the largest‐scale applications of homogeneous catalysis, and Pt homogeneous catalysts have been widely used in this reaction for the commercial manufacture of silicon products. However, homogeneous Pt catalysts result in considerable problems, such as undesired side reactions, unacceptable catalyst residues and disposable platinum consumption. Here, we synthesized electron‐deficient Pt single atoms supported on humic matter (Pt1@AHAU400), and the catalyst was used in hydrosilylation reactions, which showed super activity (turnover frequency as high as 3.0×107 h−1) and selectivity (>99 %). Density functional theory calculations reveal that the high performance of the catalyst results from the atomic dispersion of Pt and the electron deficiency of the Pt1 atoms, which is different from conventional Pt nanoscale catalysts. Excellent performance is maintained during recycle experiments, indicating the high stability of the catalyst. [ABSTRACT FROM AUTHOR]

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Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Efficient and low‐cost anode materials for the sodium‐ion battery are highly desired to enable more economic energy storage. Effects on an ultrathin carbon nitride film deposited on a copper metal electrode are presented. The combination of effects show an unusually high capacity to store sodium metal. The g‐C3N4 film is as thin as 10 nm and can be fabricated by an efficient, facile, and general chemical‐vapor deposition method. A high reversible capacity of formally up to 51 Ah g−1 indicates that the Na is not only stored in the carbon nitride as such, but that carbon nitride activates also the metal for reversible Na‐deposition, while forming at the same time an solid electrolyte interface layer avoiding direct contact of the metallic phase with the liquid electrolyte. [ABSTRACT FROM AUTHOR]

Artificial humic acids (A‐HA) made from biomass in a hydrothermal process turn otherwise highly insoluble phosphates (e.g. iron phosphate as a model) into highly available phosphorus, which contributes to the fertility of soils and the coupled plant growth. A detailed electron microscopy study revealed etching of the primary iron phosphate crystals by the ‐COOH and phenolic groups of humic acids, but also illustrated the importance of the redox properties of humic matter on the nanoscale. The combined effects result in the formation of then bioavailable phosphate nanoparticles stabilized by humic matter. Typical agricultural chemical tests indicate that the content of total P and directly plant‐available P improved largely. Comparative pot planting experiments before and after treatment of phosphates with A‐HA demonstrate significantly enhanced plant growth, as quantified in higher aboveground and belowground plant biomass. [ABSTRACT FROM AUTHOR]

Polymeric carbon nitride (PCN) is usually synthesized from nitrogen‐rich monomers such as cyanamide, melamine, and urea, but is rather disordered in many cases. Now, a new allotrope of carbon nitride with internal heterostructures was obtained by co‐condensation of very electron poor monomers (for example, 5‐amino‐tetrazole and nucleobases) in the presence of mild molten salts (for example, NaCl/KCl) to mediate the polymerization kinetics and thus modulate the local structure, charge carrier properties, and most importantly the HOMO and LUMO levels. Results reveal that the as‐prepared NaK‐PHI‐A material shows excellent photo‐redox activities because of a nanometric hetero‐structure which enhances visible light absorption and promotes charge separation in the different domains. [ABSTRACT FROM AUTHOR]

The photocatalytic CO2 reduction reaction (CRR) represents a promising route for the clean utilization of stranded renewable resources, but poor selectivity resulting from the competing hydrogen evolution reaction (HER) in aqueous solution limits its practical applicability. In the present contribution a photocatalyst with hydrophobic surfaces was fabricated. It facilitates an efficient three‐phase contact of CO2 (gas), H2O (liquid), and catalyst (solid). Thus, concentrated CO2 molecules in the gas phase contact the catalyst surface directly, and can overcome the mass‐transfer limitations of CO2, inhibit the HER because of lowering proton contacts, and overall enhance the CRR. Even when loaded with platinum nanoparticles, one of the most efficient HER promotion cocatalysts, the three‐phase photocatalyst maintains a selectivity of 87.9 %. Overall, three‐phase photocatalysis provides a general and reliable method to enhance the competitiveness of the CRR. [ABSTRACT FROM AUTHOR]

Conventional photosensing devices work mainly by electron processing and transport, while visual systems in intelligence work by integrative ion/electron signals. To realize smarter photodetectors, some photoionic device or the combination of ionic and electronic devices are necessary. Now, an ion‐transport‐based self‐powered photodetector is presented based on an asymmetric carbon nitride nanotube membrane, which can realize fast, selective, and stable light detection while being self‐powered. Local charges are continuously generated at the irradiated side of the membrane, and none (fewer) at the non‐irradiated side. The resulting surface charge gradient in carbon nitride nanotube will drive ion transport in the cavity, thus realizing the function of ionic photodetector. With advantages of low cost and easy fabrication process, the concept of ionic photodetectors based on carbon nitride anticipates wide applications for semiconductor biointerfaces. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Ions transport through confined space with characteristic dimensions comparable to the Debye length has many applications, for example, in water desalination, dialysis, and energy conversion. However, existing 2D/3D smart porous membranes for ions transport and further applications are fragile, thermolabile, and/or difficult to scale up, limiting their practical applicability. Now, polymeric carbon nitride alternatively allows the creation of an ultrathin free‐standing carbon nitride membrane (UFSCNM), which can be fabricated by simple CVD polymerization and exhibits excellent nanofluidic ion‐transport properties. The surface‐charge‐governed ion transport also endows such UFSCNMs with the function of converting salinity gradients into electric energy. With advantages of low cost, facile fabrication, and the ease of scale up while supporting high ionic currents, UFSCNM can be considered as an alternative for energy conversion systems and new ionic devices. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Polymeric carbon nitride (PCN), in either triazine or heptazine form, has been regarded as a promising metal‐free, environmentally benign, and sustainable photocatalyst for solar hydrogen production. However, PCN in most cases only exhibits moderate activity owing to its inherent properties, such as rapid charge carrier recombination. Herein we present a triazine–heptazine copolymer synthesized by simple post‐calcination of PCN in eutectic salts, that is, NaCl/KCl, to modulate the polymerization process and optimize the structure. The construction of an internal triazine–heptazine donor–acceptor (D‐A) heterostructure was affirmed to significantly accelerate interface charge transfer (CT) and thus boost the photocatalytic activity (AQY=60 % at 420 nm). This study highlights the construction of intermolecular D‐A copolymers in NaCl/KCl molten salts with higher melting points but in the absence of lithium to modulate the chemical structure and properties of PCN. [ABSTRACT FROM AUTHOR]

Abstract: Energy efficient buildings require materials with a low thermal conductivity and a high fire resistance. Traditional organic insulation materials are limited by their poor fire resistance and inorganic insulation materials are either brittle or display a high thermal conductivity. Herein we report a mechanically resilient organic/inorganic composite aerogel with a thermal conductivity significantly lower than expanded polystyrene and excellent fire resistance. Co‐polymerization and nanoscale phase separation of the phenol‐formaldehyde‐resin (PFR) and silica generate a binary network with domain sizes below 20 nm. The PFR/SiO2 aerogel can resist a high‐temperature flame without disintegration and prevents the temperature on the non‐exposed side from increasing above the temperature critical for the collapse of reinforced concrete structures. [ABSTRACT FROM AUTHOR]

Abstract: Engineering the adsorption of molecules on active sites is an integral and challenging part for the design of highly efficient transition‐metal‐based catalysts for methanol dehydrogenation. A Mott–Schottky catalyst composed of Ni nanoparticles and tailorable nitrogen‐doped carbon‐foam (Ni/NCF) and thus tunable adsorption energy is presented for highly efficient and selective dehydrogenation of gas‐phase methanol to hydrogen and CO even under relatively high weight hourly space velocities (WHSV). Both theoretical and experimental results reveal the key role of the rectifying contact at the Ni/NCF boundaries in tailoring the electron density of Ni species and enhancing the absorption energies of methanol molecules, which leads to a remarkably high turnover frequency (TOF) value (356 mol methanol mol−1 Ni h−1 at 350 °C), outpacing previously reported bench‐marked transition‐metal catalysts 10‐fold. [ABSTRACT FROM AUTHOR]

Polymeric or organic semiconductors are promising candidates for photocatalysis but mostly only show moderate activity owing to strongly bound excitons and insufficient optical absorption. Herein, we report a facile bottom-up strategy to improve the activity of a carbon nitride to a level in which a majority of photons are really used to drive photoredox chemistry. Co-condensation of urea and oxamide followed by post-calcination in molten salt is shown to result in highly crystalline species with a maximum π-π layer stacking distance of heptazine units of 0.292 nm, which improves lateral charge transport and interlayer exciton dissociation. The addition of oxamide decreases the optical band gap from 2.74 to 2.56 eV, which enables efficient photochemistry also with green light. The apparent quantum yield (AQY) for H2 evolution of optimal samples reaches 57 % and 10 % at 420 nm and 525 nm, respectively, which is significantly higher than in most previous experiments. [ABSTRACT FROM AUTHOR]

Photocatalytic Diels–Alder (D–A) reactions with electron rich olefins are realized by graphitic carbon nitride (g- C3N4) under visible-light irradiation and aerobic conditions. This heterogeneous photoredox reaction system is highly efficient, and the apparent quantum yield reaches a remarkable value of 47% for the model reaction. Dioxygen plays a critical role as electron mediator, which is distinct from the previous reports in the homogeneous RuII complex photoredox system. Moreover, the reaction intermediate vinylcyclobutane is captured and monitored during the reaction, serving as a direct evidence for the proposed reaction mechanism. The cycloaddition process is thereby determined to be the combination of direct [4+2] cycloaddition and [2+2] cycloaddition followed by photocatalytic rearrangement of the vinylcyclobutane intermediate. [ABSTRACT FROM AUTHOR]

Herein we introduce a straightforward, low cost, scalable, and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous-carbon/carbon-nanotube composite membrane, dubbed 'HNCM/CNT'. The membrane is demonstrated to function as a binder-free, high-performance gas diffusion electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency (FE) for the production of formate is 81 %. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability. [ABSTRACT FROM AUTHOR]

CO2 capture is a pressing global environmental issue that drives scientists to develop creative strategies for tackling this challenge. The concept in this contribution is to produce site-specific nitrogen doping in microporous carbon fibers. Following this approach a carbon/carbon heterojunction is created by using a poly(ionic liquid) (PIL) as a 'soft' activation agent that deposits nitrogen species exclusively on the surface of commercial microporous carbon fibers. This type of carbon-based biphasic heterojunction amplifies the interaction between carbon fiber and CO2 molecule for unusually high CO2 uptake and resistive sensing. [ABSTRACT FROM AUTHOR]

Polymer-derived carbon aerogels can be obtained by direct polymerization of monomers under hypersaline conditions using inorganic salts. This allows for significantly increased mechanical robustness and avoiding special drying processes. This concept was realized by conducting the polymerization of phenol-formaldehyde (PF) in the presence of ZnCl2 salt. Afterwards, the simultaneous carbonization and foaming process conveniently converts the PF monolith into a foam-like carbon aerogel. ZnCl2 plays a key role, serving as dehydration agent, foaming agent, and porogen. The carbon aerogels thus obtained are of very low density (25 mg cm−3), high specific surface area (1340 m2 g−1), and have a large micro- and mesopore volume (0.75 cm3 g−1). The carbon aerogels show very promising potential in the separation/extraction of organic pollutants and for energy storage. [ABSTRACT FROM AUTHOR]

Conventional polymer additives have a substantial impact on synthetic inorganic chemistry, but critical shortcomings remain; for example, low solubility in organic solvents and potential thermodynamic aggregates. Poly(ionic liquid)s have now been used as efficient additives that enable a high level control of bismuth sulfide crystals with significant size and morphological diversities. The bismuth sulfides exhibit tunable band structure as a result of the quantum size effects. Moreover, poly(ionic liquid)s are able to couple with as-synthesized bismuth sulfides chemically and endow a modified surface electronic structure, which allows resultant products to possess outstanding electrocatalytic performance for water oxidation, although its commercial counterpart is catalytically inert. [ABSTRACT FROM AUTHOR]

A novel type of quantum dot (Ph-CN) is manufactured from graphitic carbon nitride by 'lining' the carbon nitride structure with phenyl groups through supramolecular preorganization. This approach requires no chemical etching or hydrothermal treatments like other competing nanoparticle syntheses and is easy and safe to use. The Ph-CN nanoparticles exhibit bright, tunable fluorescence, with a high quantum yield of 48.4 % in aqueous colloidal suspensions. Interestingly, the observed Stokes shift of approximately 200 nm is higher than the maximum values reported for carbon nitride based fluorophores. The high quantum yield and the large Stokes shift are related to the structural surface organization of the phenyl groups, which affects the π-electron delocalization in the conjugated carbon nitride networks and induces colloidal stability. The remarkable performance of the Ph-CN nanoparticles in imaging is demonstrated by a simple incubation study with HeLa cells. [ABSTRACT FROM AUTHOR]

The investigation of nickel phosphide (Ni5P4) as a catalyst for the hydrogen (HER) and oxygen evolution reaction (OER) in strong acidic and alkaline environment is described. The catalyst can be grown in a 3D hierarchical structure directly on a nickel substrate, thus making it an ideal candidate for practical water splitting devices. The activity of the catalyst towards the HER, together with its high stability especially in acidic solution, makes it one of the best non-noble materials described to date. Furthermore, Ni5P4 was investigated in the OER and showed activity superior to pristine nickel or platinum. The practical relevance of Ni5P4 as a bifunctional catalyst for the overall water splitting reaction was demonstrated, with 10 mA cm−2 achieved below 1.7 V. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eine Kombination aus Ionothermalsynthese und Heißinjektionstechnik führte zu aus Lösungsmitteln erzeugten neuartigen Kohlenstoffnanostrukturen. Bei kontrollierter Zugabe von gewöhnlichen Lösungsmitteln zu heißer Zinkchloridschmelze entstanden sphärische, schichtartige oder verzweigt-nanofaserige Nanopartikel mit erstaunlich hoher Kohlenstoffeffizienz. Die Verwendung Heteroatom-haltiger Lösungsmittel hatte die Herstellung von Kohlen mit Dotierungsgraden von bis zu 14 Gew.-% Stickstoff und 13 Gew.-% Schwefel zur Folge. Hohe Oberflächen und große Porenvolumina der Lösungsmittelkohlen von >1666 m2 g−1 und 2.80 cm3 g−1 sowie CO2-Absorptionskapazitäten von 4.13 mmol g−1 bei 273 K und 1 bar konnten erhalten werden. Die neuartige Methode ließ sich nicht nur auf reine Kohlen anwenden, sondern wurde zudem auf die Herstellung von Nanokompositmaterialien aus Kohlenstoff und anorganischen Verbindungen ausgeweitet. ZnS@C, Ni@C und Co@C wurden erfolgreich mit der 'kinderleichten' Methode hergestellt. Das Ni@C-Nanokomposit eignet sich zur elektrokatalytischen Wasserspaltung, vergleichbar zu kommerziellen Edelmetallkatalysatoren. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride has been predicted to be structurally analogous to carbon-only graphite, yet with an inherent bandgap. We have grown, for the first time, macroscopically large crystalline thin films of triazine-based, graphitic carbon nitride (TGCN) using an ionothermal, interfacial reaction starting with the abundant monomer dicyandiamide. The films consist of stacked, two-dimensional (2D) crystals between a few and several hundreds of atomic layers in thickness. Scanning force and transmission electron microscopy show long-range, in-plane order, while optical spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations corroborate a direct bandgap between 1.6 and 2.0 eV. Thus TGCN is of interest for electronic devices, such as field-effect transistors and light-emitting diodes. [ABSTRACT FROM AUTHOR]

Efficient and low-cost electrocatalysts for the hydrogen evolution reaction are highly desired for future renewable energy systems. Described herein is the reduction of water to hydrogen using a metal-free carbon nitride electrocatalyst which operates in neutral and alkaline environments. An efficient, easy, and general method for growing ordered carbon nitride on different electrodes was developed. The metal-free catalyst demonstrates low overpotential values, which are comparable to those of non-noble metals, with reasonable current densities. The facile deposition method enables the fabrication of many electronic and photoelectronic devices based on carbon nitride for renewable energy applications. [ABSTRACT FROM AUTHOR]

The superior physical properties of carbon nanotubes (CNTs) have led to their broad application. Intrinsically, CNTs tend to agglomerate from hydrophobic interactions, which is highly undesirable for solution processing and device fabrication. Commonly, a stabilizer consisting of organic surfactants or polymers is used to disperse CNTs. Recently, we synthesized nitrogen-doped carbon hollow nanospheres (25-90 nm), termed carbon 'nanobubbles'. They bear superior dispersability in water and distinctive graphitic order. Herein, we describe the nanobubble-assisted dispersion of CNTs in aqueous solution upon sonication. This process relies on the π-π interaction between the two aromatic carbon nanostructures, which can process their carbon mixture in water into conductive filter membranes, ink, and discs. This stabilization can be extended to other aromatic carbons. In addition, the π-π interaction may create a new type of carbon p-n junction that can be used to improve charge separation. [ABSTRACT FROM AUTHOR]

Poröse N ‐ dotierte Kohlenstoffmaterialien (HTC ‐ Kohlenstoff mit PILs) aus kugelförmigen Nanopartikeln und solche mit eingebetteten Au/Pd ‐ Kern/Schale ‐ Nanopartikeln (Au/Pd@N ‐ Kohlenstoff) wurden synthetisiert. Sie sind erhältlich durch hydrothermale Verkohlung von Zuckern (160 – 200 °C) in Gegenwart polymerer ionischer Flüssigkeiten (PILs), die als Stabilisatoren, Porenbildner und Stickstoffquelle fungieren. [ABSTRACT FROM AUTHOR]

Konjugierte mikroporöse Polymere (CMPs) wurden mithilfe einer Sonogashira ‐ Hagihara ‐ Kreuzkupplung in Gegenwart von Siliciumdioxid ‐ Nanopartikeln als Template synthetisiert, wobei die spezifische Oberfläche kontrolliert werden konnte. Die CMPs sind heterogene Photosensibilisatoren für die Produktion von Singulettsauerstoff in einer kontinuierlichen Durchflusssynthese. [ABSTRACT FROM AUTHOR]