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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]

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]

A recent study published in the journal Nature has provided new insights into the charge-transfer processes that occur in photocatalytic reactions. The researchers used unique methods involving time-resolved and spatiotemporally resolved measurements to monitor these processes in Cu2O semiconductors. They found that quasi-ballistic inter-facet electron transfer and spatially selective trapping are the predominant processes that facilitate efficient charge separation in photocatalysts. This knowledge could lead to the development of high-performance semiconductors for various applications. The study utilized surface photovoltage microscopy and time-resolved photoemission electron microscopy to observe the charge-transfer processes spatially and temporally. [Extracted from the article]

Controlled radical polymerization corresponds to variety of synthetic strategies that aim the generation of precise macromolecular architectures. Iodine transfer polymerization (ITP) is one of the oldest methods to conduct controlled radical polymerization; however, it seems to have lost visibility compared to other popular techniques. It relies on utilization of iodine species in reversible deactivation kinetics, and it has some significant advantages compared to other methods. Its simplicity, minimized toxicity, metal‐free nature, no coloring on final product, and ease of purification provide widespread applicability, even in industry. In this perspective, the basics of ITP are re‐introduced, and emerging technologies (heterophase polymerization, photoinitiation, and sustainability) in ITP are discussed. [ABSTRACT FROM AUTHOR]

Interfacial tension‐driven formation of intricate microparticle geometries from complex emulsions is presented in this work. Emulsion‐templating is a reliable platform for the generation of a diverse set of microparticles. Here, water‐in‐styrene‐in‐water complex emulsions undergo reproducible metamorphosis, i.e., from liquid state emulsions to solid structured microparticles are employed. In contrast to the traditional usage of glass‐based microfluidics, polydimethylsiloxane (PDMS) swelling behavior is employed to generate complex emulsions with multiple inner cores. In the presence of block copolymer surfactant, these emulsions undergo gravity‐driven dewetting of styrene, to transform into membranous structures with compartments. Further polymerization of styrene skeletal remains resulted in microparticles with interesting geometries and intact membranes. Mechanical and confocal microscopic studies prove the absence of polystyrene within these membranes. Using osmotic pressure, membrane rupture and release of encapsulated gold nanoparticles from such polymerized emulsions leading up to applications in cargo delivery and membrane transport are promoted. Even after membrane rupture, the structured microparticles have shown interesting light‐scattering behavior for applications in structural coloring and biosensing. Thereby, proving PDMS‐based swelling as a potential methodology for reproducible production of complex emulsions with a potential to be transformed into membranous emulsions or solid microparticles with intricate structures and multiple applications. [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]

Conductive polymers find key applications ranging from optoelectronics and OLEDs to conductive composite materials. The synthesis of conductive polymers from monomers, such as thiophene derivatives, pyrroles and aniline, mainly relies on oxidative polymerization, and the processing of so‐formed (insoluble) polymers is a major issue that needs to be addressed. In the present work, oxidative photopolymerization of 3,4‐ethylenedioxythiophene (EDOT) by visible light employing the metal‐free semiconductor graphitic carbon nitride (g‐CN) is presented. Two main reaction pathways based on g‐CN content are described, and the formation of processable oligo‐EDOT is demonstrated. [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]

Complex aqueous emulsions represent a promising material platform for the encapsulation of cells, pharmaceuticals, or nutrients, for the fabrication of structured particles, as well as for mimicking the barrier-free compartmentalization of biomolecules found in living cells. Herein, we report a novel, simple, and scalable method of creating multicomponent aqueous droplets with highly uniform internal droplet morphologies that can be controllably altered after emulsification by making use of a thermal phase separation approach. Specifically, temperature-induced phase separation inside as-formed emulsion droplets comprising aqueous mixtures of two or more hydrophilic polymers allows for the generation of Janus and Cerberus emulsion droplets with adjustable internal morphologies that are solely controlled by a balance of interfacial tensions. We demonstrate our approach by applying both, microfluidic and scalable batch production, and present a detailed model study with predictive capabilities that enables fine-tuning and dynamically altering the droplet morphology as a function of types, molecular weights, and hydrophilicities of the polymers as well as the surfactant hydrophilic-lipophilic balance. The ability to rationally design complex aqueous emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new responsive soft materials with implications for a variety of applications beyond encapsulation, including the design of complex adaptive and self-regulating materials, e.g. for chemical and biological sensing applications. [ABSTRACT FROM AUTHOR]

The year 2020 marks the 100th anniversary of the first article on polymerization, published by Hermann Staudinger. It is Staudinger who realized that polymers consist of long chains of covalently linked building blocks. Polymers have had a tremendous impact on the society ever since this initial publication. People live in a world that is almost impossible to imagine without synthetic polymers. But what does the future hold for polymer science? In this article, the editors and advisory board of Macromolecular Chemistry and Physics reflect on this question. [ABSTRACT FROM AUTHOR]

Humic acid, as a natural organic matter, is widely distributed in surface soil, oceans, rivers, and other ecological environments throughout the whole earth ecosystem. Humic acid provides abundant organic carbon and helps to maintain a hydrated, pH and redox buffered environment hosting the soil microbiome. Humic acid is however also a largely ignored polymer material full of exciting functional properties, and its scale is enormous. This perspective article discusses its synthesis and management as a tool to tackle parts of the climate crisis as well its use in technological applications, as made by chemical conversion of agricultural side products to artificial humic acids. [ABSTRACT FROM AUTHOR]

Molecular photoredox complexes from the platinum group paved the way of organic photocatalysis. However, high price and difficulties related to removal and recycling hamper application of such complexes on the larger scale. Carbon nitride semiconductor photocatalysts are deprived at large extent of such limitations. Herein, we summarize application of ionic carbon nitrides in photocatalysis. A salt‐like structure of ionic carbon nitrides comprising negatively charged poly(heptazine imide) anion and positively charged alkali metal cations gives rise to a number of unique properties and high activity in photocatalysis. The performance of ionic carbon nitrides in H2 generation is up to 100 times higher compared with the covalent graphitic carbon nitrides. Eleven photocatalytic reactions mediated by ionic carbon nitrides and their long‐lived radicals are reviewed. Economy of using carbon nitride photocatalysts in comparison with the photoredox complexes from the platinum group has been analyzed. [ABSTRACT FROM AUTHOR]

A parametrization algorithm to determine chord-length distributions (CLD) from small-angle scattering data is used to characterize details of the pore structure, pore size, and morphology of porous carbon materials. This approach is applied to various carbon processing procedures, such as steam activation, tempering, and contacting with polymer binders. It is found that this CLD method reveals, compared to previous small angle x-ray scattering evaluation approaches, fine changes in the pore structure and morphology of porous carbons with higher accuracy and physical significance. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: A cost‐effective, straightforward, and environmentally benign alcohol iodination procedure with broad substrate scope is reported herein. In this reaction system, visible light and iodoform are employed as the energy source and iodination reagent, respectively. The reaction begins with the homolytic fission of the C–I bond in iodoform induced by visible‐light irradiation, producing active radicals. The following steps involve radical trapping by DMF (dimethylformamide), nucleophilic substitution, Vilsmeier‐type reagent formation, and the final iodination of the alcohol. The excellent performance of the model reaction in the flow photoreactor demonstrates the potential of this system for practical application. [ABSTRACT FROM AUTHOR]

Spherical polystyrenesulfonate particles in the size range between 7 nm

Abstract: Water splitting to its elements, either by electrochemistry or by solar light, is among the most covered areas in nanostructured functional materials. This personal account article analyzes potential downstream translation problems and reviews alternative chemistries with a potential higher return. Liberation of oxygen for accepting the holes is a kinetically demanding half reaction afflicted with kinetic hindrances and high overpotentials, while at the same time no marketable value is created (atmospheric oxygen is free to use). In spite of exciting science created, application in real industrial set‐ups is currently impossible, and possible funding promises to contribute to a sustainable society become a debt difficult to return. We discuss possible alternative targets of (photo)electrochemistry as entry points where chemical value products and technical oxidants are created, with partially greater ease, lower losses, and higher benefits. [ABSTRACT FROM AUTHOR]

Abstract: A series of salt‐templated carbons with gradually changed pore structure and their corresponding nitrogen‐doped analogues are synthesized and applied as model systems to thoroughly study the ion migration dynamics and energy storage mechanism in hierarchical pore structures with different surface functionalization in electric double‐layer capacitors with a model ionic liquid electrolyte (1‐ethyl‐3‐methylimidazolium tetrafluoroborate). Ion conformation and phase variation during the charging/discharging process and their contribution to the energy storage mechanism are investigated. A significant contribution of structural changes in the bulk of the ionic liquid electrolyte strengthening charge storage in the electric double‐layer beyond the usual expectations is uncovered. Furthermore, a quantitative model of the structure–dynamics relationship is proposed, in which the optimal ratio of mesopores to micropores is determined to be 3:1 in pore volume. Below this ratio, the ion dynamics can be promoted by increasing mesopore content and/or doping with nitrogen, while those parameters show only minor influence when the ratio is surpassing 3:1. Nitrogen doping in this system improves the rate capability (due to the enhanced ion transport dynamics) rather than the amount of energy stored. [ABSTRACT FROM AUTHOR]

A facile route to synthesize hydrophilically or hydrophobically grafted graphitic carbon nitride (g-CN) is reported. For this purpose, functionalized olefinic molecules with a low polymerization tendency are utilized for grafting onto the surface to preserve the features of g-CN while improving its dispersibility. One-pot, visible light-induced grafting yields highly dispersible g-CNs either in aqueous or organic media. Moreover, functional groups such as amines can be introduced, which yields pH-dependent dispersibility in aqueous media. Compared with unfunctionalized g-CN, low sonication times are sufficient to redisperse g-CN. In addition, because of increased dispersion stability, higher amounts of functionalized g-CN can be dispersed (up to 10% in aqueous dispersion and 2% in organic dispersion) when compared to unfunctionalized g-CN. [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]

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]

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]

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]

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]

To extend fossil oil supplies, sustainable feed stocks for the production of useful reagents and polymers should be harnessed. In this regard, chemicals derived from plants are excellent candidates. While the vast majority of plant sources used for polymer science only contain C x H y O z , alkaloids such as caffeine, nicotine, and theophylline possess nitrogen functionality that can provide new functions for bioderived polymers and their synthesis. In this context, the chemistry of theophylline, a natural product found in chocolate and tea, is exploited to create a cationic 'poly(theophylline)' in a straightforward fashion for the first time. This work demonstrates how this new polymer can be synthesized and used for the creation of narrowly disperse cationic microspheres. [ABSTRACT FROM AUTHOR]

The past decade has witnessed rapid progress in the synthesis of nanoporous organic networks or polymer frameworks for various potential applications. Generally speaking, functionalization of porous networks to add extra properties and enhance materials performance could be achieved either during the pore formation (thus a concurrent approach) or by post-synthetic modification (a sequential approach). Nanoporous organic networks which include ion pairs bound in a covalent manner are of special importance and possess extreme application profiles. Within these nanoporous ionic organic networks (NIONs), here with a pore size in the range from sub-1 nm to 100 nm, we observe a synergistic coupling of the electrostatic interaction of charges, the nanoconfinement within pores and the addressable functional units in soft matter resulting in a wide variety of functions and applications, above all catalysis, energy storage and conversion, as well as environment-related operations. This review aims to highlight the recent progress in this area, and seeks to raise original perspectives that will stimulate future advancements at both the fundamental and applied level. [ABSTRACT FROM AUTHOR]

Carbon nitride (g-CN) has attracted significant interest in the last years as a robust, low-cost alternative to metal-based materials in different fields due to its low price, environmentally benign character, simple synthesis and tunable properties. In particular, g-CN demonstrates promising activity in energy-related applications such as photo and heterogeneous catalysis, batteries and electrolysis. However, while g-CN is already well-established as a photocatalyst, its utilization in (opto)electronic devices is still at an early stage. This Focus Review concentrates on the utilization of g-CN in solar and photoelectrochemical cells, electrolyzers and light emitting diode alongside the recap of new synthetic approaches. This review is expected to provide useful insights into the design and fabrication of g-CN based photoelectronic devices as well as g-CN working principles, including the main challenges toward its integration in optoelectronic devices. [ABSTRACT FROM AUTHOR]

This review discusses different strategies for the upgrading of biomass into sustainable monomers and building blocks as scaffolds for the preparation of green polymers and materials. [ABSTRACT FROM AUTHOR]

Carbon nitrides with the increased surface areas (≈90 m2 g−1) were prepared by the heat-treatment of melamine-[Al(NO3)3]⋅9 H2O complexes. Here, [Al(NO3)3] ⋅9 H2O was successfully used as a 'green template' and a hydrogen-bonding partner of melamine, simultaneously providing a distinct porosity and defined particle morphology for the resulting carbon nitrides. The influence of the solvent and precursors ratio on the stoichiometry of the complexes, as well as the morphology, optical properties, and photocatalytic activity of resulting products for Rhodamine B degradation and sacrificial hydrogen evolution were investigated. We also studied the temperature-induced transformations of the starting complex to access the reaction mechanism. The developed synthesis procedure results in a significantly increased photocatalytic activity (up to 20-fold) compared with that of the ground reference material. [ABSTRACT FROM AUTHOR]

A facile and sustainable synthetic strategy based on the coordination of natural polyphenols with metal ions is developed for the textural engineering of mesocrystals and hierarchical carbon nanomaterials. The desired control of coordination between ellagic acid and zinc ions enables the macroscopic self-assembly behavior of crystalline nanoplatelets to be tailored into round and elongated "peanut"-like micron-sized mesostructured particles. Direct carbonization of these mesocrystals generates hierarchically porous carbon particles in good yields, possessing bimodal micro- and mesoporous architecture along with a well-preserved macroscopic structure. The pore system provides both small storage sites, demonstrated by high CO2 uptake, and transport channels also accessible by larger molecules. [ABSTRACT FROM AUTHOR]

A combination of ionothermal synthesis and hot-injection techniques leads to novel nanocarbons made from organic solvents. Controlled addition of commonly used organic solvents into a hot ZnCl2 melt gives rise to spherical, sheetlike, and branched nanofibrous carbon nanoparticles with surprisingly high carbon efficiency. When heteroatom-containing solvents were used, the doping levels reach up to 14 wt. % nitrogen and 13 wt. % sulfur. Materials with high surface areas and large pore volumes of solvent carbons as high as 1666 m2 g−1 and 2.80 cm3 g−1 in addition to CO2 adsorption capacities of 4.13 mmol g−1 at 273 K and 1 bar can be obtained. The new method works not only for pure carbon materials, but was also extended for the synthesis of carbon/inorganic nanocomposites. ZnS@C, Ni@C, and Co@C were successfully prepared with this straightforward procedure. The obtained Ni@C nanocomposites perform well in the electrocatalytic water oxidation, comparable with commercial noble-metal catalysts. [ABSTRACT FROM AUTHOR]

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]

An efficient water splitting electrocatalyst is presented. Cheap and sustainable cellulose filter paper, infiltrated with nickel acetate as the nickel source, and phenanthroline as a ligand and nitrogen source are carbonized together. Nitrogen functionalities turn out to be crucial coordination sites for the supported Ni/NiO(OH) particles. This simple and scalable one step procedure leads to powders, but also to complete membranes made of ≈10 wt% Ni, supported on nitrogen functionalized carbon. The non-noble catalyst shows a low onset potential (330 mV vs reversible hydrogen electrode), high current density (e.g., j > 25 mA cm−­2 at η = 430 mV), excellent kinetics (Tafel slope of 44 mV dec−1), and a very favorable stability (<5% decay after 10 h electrolysis) in the oxygen evolution. The performance is similar or even better compared to state-of-the-art noble metal catalysts (e.g., IrO2, Ir/C, Ru/C, and Pt/C). Because of the simple, cheap, and scalable preparation procedure the catalyst is highly promising for practical low price/tech applications. Interestingly, the system is also active in the hydrogen evolution reaction, leading to a promising bifunctional catalyst. The benchmark characteristics are η10 = 390 mV for oxygen evolution and η10 = 190 mV for hydrogen evolution, that is, an overall efficiency of 68% at 10 mA current density. [ABSTRACT FROM AUTHOR]

A simple, versatile and cheap synthetic route is demonstrated for the preparation of Co3O4 decorated blood powder derived heteroatom doped porous carbon (BDHC). The inorganic hybrid performs well as an advanced bifunctional non-precious metal electrocatalyst. The hybridization of Co3O4 with the blood-derived carbon results in improved activities not only towards the oxygen reduction reaction (ORR), but also in the reverse oxygen evolution reaction (OER). An improved ORR activity and a tuned four electron transfer selectivity can be assigned to a synergistic catalytic effect due the intimate contact between Co3O­4 particles and the highly conductive heteroatom doped carbon support, mediated by cobalt-nitrogen or cobalt-phosphorous coordination sites. This heterojunction may facilitate the electron transfer by preventing an accumulation of electron density within the Co3O­4 particles. The straight-forward and cheap synthesis of the highly active and durable electrocatalyst make it a promising candidate for a next-generation bifunctional electrocatalyst for applications such as reversible fuel cells/electrolyzers or metal air batteries. [ABSTRACT FROM AUTHOR]

Spherical poly(ionic liquid) (PIL) nanoparticles of different size (25-70 nm) were synthesized and applied as a novel colloidal soft template for the preparation of meso- and macroporous inorganics, here exemplified with silica and its metal nanoparticle doping via nanocasting. Pore size and pore architecture can be adjusted by appropriate choice of the template and the reaction conditions. Unexpectedly, it was found that the in situ generated methanol plays a very important role during the casting process. It enlarged the overall surface area by introducing a significant fraction of micropores and small mesopores. The largest specific surface area was obtained at an optimized ratio of tetramethyl orthosilicate (TMOS) to PIL nanoparticle. In addition, PIL nanoparticles pre-functionalized with Pt metal nanoparticles were used in the same manner as hybrid templates for nanocasting. The pyrolysis conditions were optimized to synthesize mesoporous silica functionalized with uniformly distributed metal nanoparticles of very small size in a one-pot process. [ABSTRACT FROM AUTHOR]

Ionic liquids were prepared via hydrothermal decarboxylation of zwitterionic imidazolium compounds derived from amino acids and carbohydrate related dicarbonyl compounds. Two of these ionic liquids were used successfully as solvents in the Heck reaction and for the dissolution of cellulose. [ABSTRACT FROM AUTHOR]

In recent years, the simple synthesis of artificial humic substances (A-HS) by alkaline hydrothermal processing of waste biomass was described. This A-HS was shown to support water and mineral binding, to change soil structure, to avoid fertilizer mineralization, and to support plant growth. Many of the observed macroscopic effects could, however, not be directly related to the minute amounts of A-HS which have been added, and an A-HS stimulated microbiome was found to be the key for understanding. In this review, we describe such anthropogenic soil in the language of the modern concept of living engineered materials and identify natural and artificial HS as the enabler to set up the interactive microbial system along the interfaces of the mineral grains. In that, old chemical concepts as surface activity, redox mediation, and pH buffering are the base of the system structure build-up and the complex self-adaptability of biological systems. The resulting chemical/biological hybrid system has the potential to address world problems as soil fertility, nutrition of a growing world population, and climate change. [ABSTRACT FROM AUTHOR]

MXenes, a rapidly growing family of 2D transition metal carbides, carbonitrides, and nitrides, are one of the most promising high‐rate electrode materials for energy storage. Despite the significant progress achieved, the MXene synthesis process is still burdensome, involving several procedures including preparation of MAX, etching of MAX to MXene, and delamination. Here, a one‐pot molten salt electrochemical etching (E) method is proposed to achieve Ti2C MXene directly from elemental substances (Ti, Al, and C), which greatly simplifies the preparation process. In this work, different carbon sources, such as carbon nanotubes (CNT) and reduced graphene oxide (rGO), are reacted with Ti and Al micro‐powders to prepare Ti2AlC MAX with 1D and 2D tuned morphology followed by in situ electrochemical etching from Ti2AlC MAX to Ti2CTx MXene in low‐cost LiCl‐KCl. The introduction of the O surface group via further ammonium persulfate (APS) treatment can act in concert with Cl termination to activate the pseudocapacitive redox reaction of Ti2CClyOz in the non‐aqueous electrolyte, resulting in a Li+ storage capacity of up to 857 C g−1 (240 mAh g−1) with a high rate (86 mAh g−1 at 120 C) capability, which makes it promising for use as an anode material for fast‐charging batteries or hybrid devices in a non‐aqueous energy storage application. [ABSTRACT FROM AUTHOR]

Abstract: We report here a molten salt (MS) process for the synthesis of nanoporous carbon structures and carbon sheets. Using glucose as the model carbon precursor, the process yields different porous carbon structures with specific surface area up to near 2000m2/g in molten LiCl/KCl containing different dissolved oxysalts KNmO x , where Nm are nonmetal elements of H, B, C, N, P, S, and Cl. These oxysalts dissolved in LiCl/KCl exert a dominating influence on the pore formation as well as two-dimensional growth of the carbons in MS. Based on the energetics of the redox reaction between carbon and the above oxysalts, a general mechanistic explanation for the pore formation and the activation process in MS is presented. The process reported here not only provides an easy route to convert biomass molecules to carbon-based functional nanomaterials, but also opens up a new direction towards carbonization and two-dimensional growth in high temperature ionic solvent systems. [Copyright &y& Elsevier]

Thesynthesis of carbon aerogels by sol–gel like processes,i.e., hard templating, phase demixing, hydrothermal carbonizationtechniques, as well as by ionothermal syntheses are reviewed. In allthese techniques, we start with a liquid reaction solution, wherecontrolledby experimental parameters and structure-directing additivesaporous carbon material with high conductivity, high pore volume, andhigh specific surface area is obtained. Many of these synthesis approachesgive the resulting material in simple, rather sustainable processes,and the structures can be employed directly after isolation withoutfurther activation processes. The article will discuss also some applications,such as battery and electrode materials as well as catalyst supports. [ABSTRACT FROM AUTHOR]

Porous carbons and porous carbon nitrides are well known support materials. Some of these materials are, however, not only a geometric construct for immobilization, enabling mass transport at the same time, but contribute due to their extended electronic structure to a potential catalytic event as such. When appropriate band schemes and electron reactivity are chosen, immobilized metal nanoparticles can exhibit a highly enhanced chemical reactivity. This is due to electronic interaction and electron transfer between the metal and semiconductor, as introduced by Mott and Schottky for planar metal–semiconductor interfaces. A rational choice of mesoporous semiconductor and metal particle allows to create a new generation of catalysts and catalytic schemes with unparalleled performances. This tutorial review highlights the latest development in the synthesis and applications of mesoporous N-doped carbon and carbon nitride supported metal nanoparticles, and concentrates on the catalytic effect of the charge transfer between the metal nanoparticles and semiconductive components. [ABSTRACT FROM AUTHOR]

The carbon nitride poly(triazine imide) with intercalated bromide ions is a layered, graphitic material of 2D covalently bonded molecular sheets with an exceptionally large gallery height of 3.52 Å due to the intercalated bromide anions. The material can be cleaved both mechanically and chemically into thin sheets and scrolls analogous to the carbon-only systems graphite and graphene. [ABSTRACT FROM AUTHOR]

Siliconcarbide (SiC) is a compound with strong covalent bonding,which gives its high mechanical strength and oxidation resistance,but also hinders its synthesis under moderate conditions. Herein,a facile route is presented for the synthesis of SiC nanomaterialsfrom simple and abundant raw materials in an inorganic molten salt(MS). With this route, we are able to synthesis nanoscale 3C-SiC and2H-SiC in a controlled manner, where the choice of cubic or hexagonalstructure is coupled to nanocrystal size. By selection of the startingmaterials and tuning of the synthesis conditions, the MS-derived SiCcan be isolated as nanoparticles (NPs), porous SiC/C composites withsmall primary crystals (2–4 nm), and as nanospheres. We alsoshow that the SiC nanostructures are active for electrochemical hydrogenevolution reaction, and the activity can be remarkably improved byloading Pt (NPs) onto the structure. [ABSTRACT FROM AUTHOR]

Polymerized ionic liquid (PIL) nanoparticles are for the first time applied as sole stabilizers in aqueous emulsion polymerization and reveal an astonishing and unexpected behavior. In a well-dispersed state, the PIL nanoparticles serve as an unexpectedly effective stabilizer for polystyrene dispersions, enabling solids content of greater than 40%. However, the same PIL as dry powder is hydrophobic and, in accordance with Bancroft's rule, unable to stabilize aqueous dispersions. This ambivalent behavior of PIL is extremely beneficial for the application of aqueous dispersions because, as desired for decades, the hydrophilic dispersed state during synthesis turns hydrophobic in the dried state during application of the polymer. [ABSTRACT FROM AUTHOR]

The unique properties of 2D MXenes, such as metal‐like electrical conductivity and versatile surface chemistry, make them appealing for various applications, including energy storage. While surface terminations of 2D MXene are expected to have a key influence on their electrochemical properties, the conventional HF‐etching method limits the surface functional groups to F, OH, and O. In this study, O‐free, Cl‐terminated MXenes (noted as Ti3C2Clx) are first synthesized by a molten salt (FeCl2) etching route. Then, a substitution of surface termination from Cl to N is performed via post‐thermal treatment of Ti3C2Clx in Li3N containing molten salt electrolytes. While the Cl‐terminated pristine material does not show electrochemical activity, the surface‐modified, N‐containing Ti3C2Tx exhibits a unique capacitive‐like electrochemical signature in sulfuric acid aqueous electrolyte with rate performance—more than 300 F g−1 (84 mAh g−1) at 2 V s−1. These results show that control of the MXene surface chemistry enables the preparation of high‐performance electrodes in a previously not accessed limit of energy storage. [ABSTRACT FROM AUTHOR]

Switchable, organic microporous networks were synthesizedby Sonogashiracoupling of tetrabromophenolphthalein with 1,4-diethynylenebenzeneusing optimized reaction conditions. The resulting networks are microporousand have specific surface areas exceeding 800 m2g–1. The microporosity and the pore polarity are sensitiveto the pH value as evidenced by nitrogen and carbon dioxide physisorptionexperiments. The switching between the open and closed form of thelactone ring is reversible, but some porosity is lost throughout theprocess. The colored, alkaline salts of these networks are photochemicallyactive, as shown by the effective heterogeneous photosensitizationof the photopolymerization of methyl methacrylate with visible light. [ABSTRACT FROM AUTHOR]