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Abstract: Introducing band gap states to TiO2 photocatalysts is an efficient strategy for expanding the range of accessible energy available in the solar spectrum. However, few approaches are able to introduce band gap states and improve photocatalytic performance simultaneously. Introducing band gap states by creating surface disorder can incapacitate reactivity where unambiguous adsorption sites are a prerequisite. An alternative method for introduction of band gap states is demonstrated in which selected heteroatoms are implanted at preferred surface sites. Theoretical prediction and experimental verification reveal that the implanted heteroatoms not only introduce band gap states without creating surface disorder, but also function as active sites for the CrVI reduction reaction. This promising approach may be applicable to the surfaces of other solar harvesting materials where engineered band gap states could be used to tune photophysical and ‐catalytic properties. [ABSTRACT FROM AUTHOR]

Abstract: Solar CO2 reduction efficiency is largely limited by poor photoabsorption, sluggish electron–hole separation, and a high CO2 activation barrier. Defect engineering was employed to optimize these crucial processes. As a prototype, BiOBr atomic layers were fabricated and abundant oxygen vacancies were deliberately created on their surfaces. X‐ray absorption near‐edge structure and electron paramagnetic resonance spectra confirm the formation of oxygen vacancies. Theoretical calculations reveal the creation of new defect levels resulting from the oxygen vacancies, which extends the photoresponse into the visible‐light region. The charge delocalization around the oxygen vacancies contributes to CO2 conversion into COOH* intermediate, which was confirmed by in situ Fourier‐transform infrared spectroscopy. Surface photovoltage spectra and time‐resolved fluorescence emission decay spectra indicate that the introduced oxygen vacancies promote the separation of carriers. As a result, the oxygen‐deficient BiOBr atomic layers achieve visible‐light‐driven CO2 reduction with a CO formation rate of 87.4 μmol g−1 h−1, which was not only 20 and 24 times higher than that of BiOBr atomic layers and bulk BiOBr, respectively, but also outperformed most previously reported single photocatalysts under comparable conditions. [ABSTRACT FROM AUTHOR]

Abstract: Currently, it still remains a challenge to amplify the spectrum of chemical fixation of CO2, although enormous progress has been achieved in this field. In view of the widespread applications of CO in a myriad of industrial carbonylation processes, an alternative strategy is proposed in which CO2 reduction to CO is combined with carbonylation with CO generated ex situ, which affords efficiently pharmaceutically and agrochemically attractive molecules. As such, CO2 in this study was efficiently reduced by triphenysilane using CsF to CO in a sealed two‐chamber reactor. Subsequently, palladium‐catalyzed aminocarbonylation, carbonylative Sonogashira coupling of aryl iodides, and rhodium(I)‐mediated Pauson–Khand‐type reaction proceeded smoothly to yield amides, alkynones, and bicyclic cyclopentenones, respectively. Furthermore, the formed alkynones can further be successfully converted to a series of heterocycles, for example, pyrazoles, 3a‐hydroxyisoxazolo[3,2‐a]isoindol‐8‐(3aH)‐one derivatives and pyrimidines in moderate yields. The striking features of this protocol include operational simplicity, high efficiency, and relatively broad application scope, which represents an alternative avenue for CO2 transformation. [ABSTRACT FROM AUTHOR]

This study reports that aquahydroxocobinamide [(H2O)(HO–)Cbi(III)], a nucleotide‐free analogue of cobalamin (vitamin B12; Cbl), is capable of catalyzing the reduction of the two‐electron oxidized form of vitamin C, dehydroascorbic acid (DHA), to ascorbic acid by glutathione (GSH), whereas catalytic quantities of aquacobalamin do not accelerate the reaction. This observation is explained by different reactions taking place with the CoIII‐species of these complexes and GSH: Cbl(III) forms a stable complex with GSH, but Cbi(III) is relatively rapidly reduced to Cbi(II). The reaction of Cbi(II) with DHA in the presence of GSH includes the coordination of GSH onto CoII, the reaction of GS––Cbi(II) with DHA produces GS––Cbi(III) and the ascorbyl radical, which rapidly disproportionates to a mixture of ascorbic and dehydroascorbic acids, and further regeneration of Cbi(II). [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of CO2 provides an opportunity to reach a carbon‐neutral energy recycling regime, in which CO2 emissions from fuel use are collected and converted back to fuels. The reduction of CO2 to CO is the first step toward the synthesis of more complex carbon‐based fuels and chemicals. Therefore, understanding this step is crucial for the development of high‐performance electrocatalyst for CO2 conversion to higher order products such as hydrocarbons. Here, atomic iron dispersed on nitrogen‐doped graphene (Fe/NG) is synthesized as an efficient electrocatalyst for CO2 reduction to CO. Fe/NG has a low reduction overpotential with high Faradic efficiency up to 80%. The existence of nitrogen‐confined atomic Fe moieties on the nitrogen‐doped graphene layer is confirmed by aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy and X‐ray absorption fine structure analysis. The Fe/NG catalysts provide an ideal platform for comparative studies of the effect of the catalytic center on the electrocatalytic performance. The CO2 reduction reaction mechanism on atomic Fe surrounded by four N atoms (Fe–N4) embedded in nitrogen‐doped graphene is further investigated through density functional theory calculations, revealing a possible promotional effect of nitrogen doping on graphene. [ABSTRACT FROM AUTHOR]

In order to limit the side effects associated with antitumor drugs such as doxorubicin, nanosized drug‐delivery systems capable of selectively delivering and releasing the drug in the diseased tissue are required. We describe nanoparticles (NPs), self‐assembled from a reduction responsive amphiphilic peptide, capable of entrapping high amounts of a redox active anticancer drug candidate and releasing it in presence of a reducing agent. This system shows a high entrapment efficiency with up to 15 mg drug per gram of peptide (5.8 mol‐%). Treatment of the NPs with reducing agent results in the disassembly of the NPs and release of the drug molecules. A reduction in cell viability is observed at drug concentrations above 250 n m in HEK293T and HeLa cell lines. This drug delivery system has potential for targeting tumor sites via the EPR effect while taking advantage of the increased reduction potential in tumor microenvironment. [ABSTRACT FROM AUTHOR]

Abstract: In an effort to develop a more environmentally benign flame retardant for polyurethane foam (PUF), layers of halloysite clay nanotubes (HNT) stabilized by branched polyethylenimine (BPEI) or poly(acrylic acid) (PAA) are deposited from aqueous suspensions to create multilayered nanocomposite coatings. PUF is very flammable and widely used in upholstered furniture throughout the world. Foam treated with five BPEI‐HNT/PAA‐HNT bilayers, deposited using layer‐by‐layer assembly, is rendered self‐extinguishing in open flame testing. Cone calorimetry reveals that this coating reduces the peak heat release rate (pkHRR) by 62%. Due to the tubular morphology of HNT, small volatile gasses given off during combustion are trapped, so total smoke release (TSR) is reduced by 60%. Infrared spectroscopy suggests this multilayer film survives during combustion, forming an HNT‐rich barrier that prevents mass and energy transfer during open flame testing and calorimetry. The significant reductions in pkHRR and TSR, along with the self‐extinguishing behavior, indicate that these halloysite‐based multilayer films have the potential to greatly improve PUF fire safety. The low cost and natural abundance of HNT makes this technology especially amenable to widespread use. [ABSTRACT FROM AUTHOR]

Abstract: Oxynitrides are promising visible‐light‐responsive photocatalysts, but their structures are almost confined with three‐dimensional (3D) structures such as perovskites. A phase‐pure Li2LaTa2O6N with a layered perovskite structure was successfully prepared by thermal ammonolysis of a lithium‐rich oxide precursor. Li2LaTa2O6N exhibited high crystallinity and visible‐light absorption up to 500 nm. As opposed to well‐known 3D oxynitride perovskites, Li2LaTa2O6N supported by a binuclear RuII complex was capable of stably and selectively converting CO2 into formate under visible light (λ>400 nm). Transient absorption spectroscopy indicated that, as compared to 3D oxynitrides, Li2LaTa2O6N possesses a lower density of mid‐gap states that work as recombination centers of photogenerated electron/hole pairs, but a higher density of reactive electrons, which is responsible for the higher photocatalytic performance of this layered oxynitride. [ABSTRACT FROM AUTHOR]

Abstract: Bonding is a fundamental aspect of organic chemistry, yet the magnitude of C=C bonding in [n]cumulenes as a function of increasing chain length has yet to be experimentally verified for derivatives longer than n=5. The synthesis of a series of apolar and unsymmetrically substituted tetraaryl[n]cumulenes (n=3, 5, 7, 9) was developed and rotational barriers for Z/E isomerization were measured using dynamic VTNMR spectroscopy. Both experiment and theory confirm a dramatic reduction in the rotational barrier (through estimation of ΔG≠rot for the isomerization) across the series, from >24 to 19 to 15 to 11 kcal−1 in [n]cumulenes with n=3, 5, 7, 9, respectively. The reduction in cumulenic bonding in longer cumulenes thus affords bond rotational barriers that are more characteristic of a sterically hindered single bond than that of a double bond. [ABSTRACT FROM AUTHOR]

Abstract: Coordination of redox‐active ligands to metals is a compelling strategy for making reduced complexes more accessible. In this work, we explore the use of redox‐active formazanate ligands in low‐coordinate iron chemistry. Reduction of an iron(II) precursor occurs at milder potentials than analogous non‐redox‐active β‐diketiminate complexes, and the reduced three‐coordinate formazanate‐iron compound is characterized in detail. Structural, spectroscopic, and computational analysis show that the formazanate ligand undergoes reversible ligand‐centered reduction to form a formazanate radical dianion in the reduced species. The less negative reduction potential of the reduced low‐coordinate iron formazanate complex leads to distinctive reactivity with formation of a new N−I bond that is not seen with the β‐diketiminate analogue. Thus, the storage of an electron on the supporting ligand changes the redox potential and enhances certain reactivity. [ABSTRACT FROM AUTHOR]

Abstract: High‐resolution soil and groundwater monitoring was performed to assess the long‐term impacts of bioremediation using bioaugmentation with a dechlorinating microbial consortium (and sodium lactate as the electron donor) in a well‐characterized trichloroethene (TCE) dense nonaqueous phase liquid (DNAPL) source area. Monitoring was performed up to 3.7 years following active bioremediation using a high‐density monitoring network that included several discrete interval multi‐level sampling wells. Results showed that despite the absence of lactate, lactate fermentation transformation products, or hydrogen, biogeochemical conditions remained favorable for the reductive dechlorination of chlorinated ethenes. In locations where soil data showed that TCE DNAPL sources persisted, local contaminant rebound was observed in groundwater, whereas no rebound or continuous decreases in chlorinated ethenes were observed in locations where DNAPL sources were treated. While ethene levels measured 3.7 years after active treatment suggested relatively low (2 to 30%) dechlorination of the parent TCE and daughter products, carbon stable isotope analysis showed that the extent of complete dechlorination was much greater than indicated by ethene generation and that the estimated first‐order rate constant describing the complete dechlorination of TCE at 3.7 years following active bioremediation was approximately 3.6 y–1. Overall, results of this study suggest that biological processes may persist to treat TCE for years after cessation of active bioremediation, thereby serving as an important component of remedial treatment design and long‐term attenuation. [ABSTRACT FROM AUTHOR]

Abstract: The oxygen reduction reaction (ORR) is typically slow. Its kinetics, however, are influenced not only by the structure, nature, and doping of electrocatalysts, but also by the loadings of these materials, where all of these factors influence ORR selectivity to produce H2O and/or H2O2. The loadings employed for graphene nanoribbon (GNR)‐modified glassy carbon (GC) electrodes and GC disk modified with commercial Pt (20 wt.%) on carbon (PtC) at 150 μg cm−2 (also resulting in electrode roughness) produced turbulence in the electrolyte flow, significantly changing the geometry of the rotating ring‐disk electrode (RRDE) and collection efficiency (N), as well as causing N to change with the rotation rate of the electrode. This effect toward the ORR was investigated with two analytical methods derived by Wu et al. and Zhou et al. A current deconvolution method for a better‐resolved Tafel analysis separating H O 2 - formation and reduction reactions resulted in more insightful understanding of the ORR responses provided by the RRDE for different GNR and PtC loadings. [ABSTRACT FROM AUTHOR]

Synthesis of silver nanoparticles (AgNPs) was carried out in aqueous solutions. Silver nitrate was used as precursor, carboxymethyl cellulose (CMC) as stabilising agent, and sodium borohydride as reducing agent. The reaction was semicontinuous by feeding both the precursor and reducing agent into the stabilising agent aqueous solution in an alternated fashion. Weight ratios of 1:1 AgNO3:CMC were used in the reduction reactions. AgNPs were characterised by UV-vis spectroscopy, transmission electronic microscopy (TEM), and X-ray diffraction. The formation of AgNPs was confirmed by the presence of an absorption peak about 400 nm using UV-vis spectrophotometry. Spheroidal nanoparticles with an average diameter between 5 and 90 nm were observed by TEM. High productivity of AgNPs was obtained at lower reaction times and at low temperature compared with others previously reported in the literature. [ABSTRACT FROM AUTHOR]

Catalytic hydroboration and cyanosilylation of a wide range of aldehydes and ketones, with pinacolborane (4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane) and trimethylsilyl cyanide, respectively, in the presence of titanium(IV) complexes [κ2‐{(C5H4N)CH2N‐P(=Se)Ph2}Ti(NMe2)3] (1) and [{κ2‐(C6H4F)NP(=Se)Ph2}Ti(NMe2)3] (2) are reported. The catalytic hydroboration and cyanosilylation processes are high‐yielding and general, and result in efficient conversion of carbonyl compounds into the corresponding products under mild conditions. Titanium catalyst 1 exhibits high tolerance toward several functional groups. First‐order kinetics with respect to the catalyst and each of the substrates were observed for the titanium‐catalyzed hydroboration of carbonyl compounds. First‐principles calculations were performed to explore the catalytic hydroboration reaction mechanism. In addition, a combination of both reactions and sequential cyanosilylation/hydroboration is reported. TiIV complexes 1 and 2 were prepared by aminolysis of [Ti(NMe2)4] with protic ligands [(C5H4N)CH2NHP(=Se)Ph2] (L1H) and [(C6H4F)NHP(=Se)Ph2] (L2H), respectively. The third titanium complex [κ4‐{Ph2P(=Se)NCH(C5H4N)CH(C5H4N)P(=Se)Ph2}‐Ti(NMe2)2] (3) was obtained from the reaction between [Ti(NMe2)4] and ligand L1H in a 1:2 molar ratio at room temperature. The molecular structures of complexes 1 and 3 in the solid state are reported. [ABSTRACT FROM AUTHOR]

Abstract: A dinuclear CoII complex, [Co2(tphz)(tpy)2]n+ (n=4, 3 or 2; tphz: tetrapyridophenazine; tpy: terpyridine), has been assembled using the redox‐active and strongly complexing tphz bridging ligand. The magnetic properties of this complex can be tuned from spin‐crossover with T1/2≈470 K for the pristine compound (n=4) to single‐molecule magnet with an ST=5/2 spin ground state when once reduced (n=3) to finally a diamagnetic species when twice reduced (n=2). The two successive and reversible reductions are concomitant with an increase of the spin delocalization within the complex, promoting remarkably large magnetic exchange couplings and high‐spin species even at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: The transformation of CO2 into fuels and chemicals by photocatalysis is a promising strategy to provide a long‐term solution to mitigating global warming and energy‐supply problems. Achievements in photocatalysis during the last decade have sparked increased interest in using sunlight to reduce CO2. Traditional semiconductors used in photocatalysis (e.g. TiO2) are not suitable for use in natural sunlight and their performance is not sufficient even under UV irradiation. Some two‐dimensional (2D) materials have recently been designed for the catalytic reduction of CO2. These materials still require significant modification, which is a challenge when designing a photocatalytic process. An overarching aim of this Review is to summarize the literature on the photocatalytic conversion of CO2 by various 2D materials in the liquid phase, with special attention given to the development of novel 2D photocatalyst materials to provide a basis for improved materials. [ABSTRACT FROM AUTHOR]

Abstract: The reductive coupling of two diazomethanes is affected by reaction with [(NacNacMes)Mg]2 affording the species [(NacNacMes)Mg(N2CPh2)]2 2 and [(NacNacMes)Mg(N2C(C6H4)2)]2 3. These species containing N4 linkages readily evolve the central N2 at 50 and 75 °C to give the Mg–imide products [(NacNacMes)Mg(NCPh2)]2 (4) and [(NacNacMes)Mg(NC(C6H4)2)]2 (5), respectively. The mechanism for the loss of N2 was considered computationally. Compounds 2 and 3 reacted with O2 to liberate the tetrazene (Ph2N2)2 6 and the hydrazine ((C6H4)2CN)2 7, whereas reactions with Me3SiOSO2CF3 or Me3SiCl with 2 and 3 provide the related silyl imines 8 and 9, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light‐driven methods to reduce CO2 to form energy‐rich carbon‐based products. Because CO2 reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO2 adsorption on a catalyst and proton transfer to CO2 are two important factors for the conversion reaction, and catalysts with high surface area and more active sites are required to improve the efficiency of CO2 reduction. Here, a visible light‐driven system for CO2‐to‐CO conversion is reported, which consists of a heterogeneous hybrid catalyst of Co and Co2P nanoparticles embedded in carbon nanolayers codoped with N and P (Co‐Co2P@NPC) and a homogeneous RuII‐based complex photosensitizer. The average generation rate of CO of the system was up to 35 000 μmol h−1 g−1 with selectivity of 79.1 % in 3 h. Linear CO production at an exceptionally high rate of 63 000 μmol h−1 g−1 was observed in the first hour of reaction. Inspired by this highly active catalyst, Co@NC and Co2P@NPC materials were also synthesized and their structure, morphology, and catalytic properties for CO2 photoreduction were explored. The results showed that the nanoparticle size, partially adsorbed H2O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO2 reduction performance. [ABSTRACT FROM AUTHOR]

Abstract: Imine‐to‐amine conversion with catalytic instead of stoichiometric quantities of LiAlH4 is demonstrated (85 °C, catalyst loading≥2.5 mol %, pressure≥1 bar). The effects of temperature, pressure, solvent, and catalyst modifications, as well as the substrate scope are discussed. Experimental investigations and preliminary DFT calculations suggest that the catalytically active species is generated in situ: LiAlH4+Ph(H)C=NtBu→LiAlH2[N(tBu)CH2Ph]2. A cooperative mechanism in which Li and Al both play a prominent role is proposed. [ABSTRACT FROM AUTHOR]

Abstract: Reduction methods for the preparation of coordination complexes of titanium(IV) and indium(III) phthalocyanines (Pc) with organic dyes such as indigo, thioindigo, and squarylium dye III (SQ) have been developed, which allow one to obtain crystalline {cryptand(K+)}{(cis‐indigo‐O,O)2−TiIV(Pc2−)}(Cl−)⋅C6H4Cl2 (1), {cryptand(K+)}{(cis‐thioindigo‐O,O)2−InIII(Pc2−)}−⋅C6H4Cl2 (2), and {cryptand(K+)}{[(SQ)2‐O,O]2−InIII(Pc2−)}−⋅3.5 C6H4Cl2 (3) complexes. The formation of these complexes is accompanied by the reduction of the starting dyes to the anionic state. Transition of trans‐indigo or trans‐thioindigo to the cis conformation in 1 and 2 provides coordination of both carbonyl oxygen atoms of the dye to TiIVPc or InIIIPc. SQ is reduced to the radical anion state and forms unusual diamagnetic singly bonded (SQ−)2 dimers in 3. These dimers have two closely positioned carbonyl oxygen atoms coordinated to InIIIPc. Dianionic Pc2− macrocycles have been found in 1–3. The complexes contain two chromophore molecules at one metal center. However, their optical spectra are defined mainly by absorption bands of the metal phthalocyanines. [ABSTRACT FROM AUTHOR]

Abstract: Density functional theory (DFT) was utilized to explore the reduction of gold(III) complexes by the amino acid glycine (Gly). Interestingly, when the nitrogen atom of Gly coordinates to the gold(III) center, its Cα‐hydrogen atom becomes so acidic that it can be easily deprotonated by a mild base like water. The deprotonation converts the amino acid into a potent reductant by which gold(III) is reduced to gold(I) with a moderate activation energy. To our knowledge, this is the first contribution suggesting that primary amines are oxidized to imines via direct α‐carbon deprotonation. This finding may provide new insights into the mechanistic interpretation of amine oxidations catalyzed/mediated by a center with high cathodic reduction potential. This work also provides a rationalization behind why gold(III) complexes with amine‐based polydentate ligands are reluctant to undergo a redox process. Gold(III) reduction occurs most efficiently if the Cα proton leaves in the plane of the Cα, N and Au atoms. Chelation prevents this alignment, resulting in the gold(III) complex being unreactive toward reduction. It has been experimentally found that gold(III) is capable of oxidizing Gly to glyoxylic acid (GA) as the initial product. The latter, in the presence of another gold(III) complex, has been reported to undergo oxidative decarboxylation to afford CO2 and HCOOH. This process is found to be mediated by formation of a geminal diol intermediate produced by reaction of water with the aldehyde functional group of the coordinated GA. [ABSTRACT FROM AUTHOR]

Abstract: Described here is an efficient stereoselective synthesis of vibegron enabled by an enzymatic dynamic kinetic reduction that proceeds in a high‐pH environment. To overcome enzyme performance limitations under these conditions, a ketoreductase was evolved by a computationally and structurally aided strategy to increase cofactor stability through tighter binding. [ABSTRACT FROM AUTHOR]

Abstract: Selective electrochemical measurements of epinephrine (EP) and norepinephrine (NE) in the presence of large excess of the common interfering ascorbic acid (AA) and uric acid (UA) are accomplished using cyclic square‐wave voltammetry (C‐SWV) at unmodified carbon electrodes. Such use of bare carbon electrodes is based on monitoring the reduction peaks of the EP and NE oxidation products and relies on the reversible electrochemical behavior of these catecholamines compared to that of AA and UA and on the rich information content and high speed and sensitivity of C‐SWV. Detection limits of 3 μM EP and NE are estimated in the presence of 100 fold excess AA and UA. The C‐SWV operation at the uncoated carbon electrode facilitates also the simultaneous measurements of EP and NE. The new C‐SWV protocol enhances the resolving power of unmodified carbon electrodes and represents an extremely useful and simple addition to the arsenal of electrochemical techniques for real‐time monitoring of dynamic brain processes. [ABSTRACT FROM AUTHOR]

Nanocomposites of gold nanoparticles and polyaniline are synthesized by using HAuCl4 and ammonium peroxydisulfate as the co‐oxidant involving in situ polymerization of aniline and in situ reduction of HAuCl4. Through these in situ methods, the synthesized Au nanoparticles of ca. 20 nm embedded tightly and dispersed uniformly in polyaniline backbone. With the Au content in composite increasing from 4.20 to 24.72 wt.%, the specific capacitance of the materials first increased from 334 to 392 F g−1 and then decreased to 298 F g−1. Based on the real content of PANI in composite material, the highest specific capacitance is calculated to be 485 F g−1 at the Au amount of 19.15 wt.%, which remains 55.6% after 5000 cycles at the current density of 2 A g−1. Finally, the asymmetric supercapacitor of AuNP/PANI||AC and the symmetric supercapacitor of AuNP/PANI||AuNP/PANI are assembled. The asymmetric supercapacitor device shows a better electrochemical performance, which delivers the maximum energy density of 7.71 Wh kg−1 with power density of 125 W kg−1 and maximum power density of 2500 W kg−1 with the energy density of 5.35 Wh kg−1. [ABSTRACT FROM AUTHOR]

Abstract: Background: The future supply of platinum group metals (PGM) is at risk because of their scarcity combined with a high demand. Thus recovery of platinum (Pt) from waste is an option worthy of study to help alleviate future shortages. This research explored the microbial reduction of platinum (Pt). The ability of anaerobic granular sludge to reduce Pt(IV) ions under different physiological conditions was studied. Results: X‐ray diffraction (XRD) and transmission electron microscope (TEM) analyses demonstrated the capacity of the microbial mixed culture to reduce Pt(IV) to Pt(0) nanoparticles, which were deposited on the cell‐surface and in the periplasmic space. Ethanol supported the biologically catalyzed Pt(IV) reduction, meanwhile other electron donors; hydrogen (H2) and formate, promoted the chemical reduction of Pt(IV) with some additional biological stimulation in the case of H2. A hypothesis is proposed in which H2 formed from the acetogenesis of ethanol is implicated in subsequent abiotic reduction of Pt(IV) indicating an integrated bio‐chemical process. Endogenous controls also resulted in slow Pt(IV) removal from aqueous solution. Selected redox mediators, exemplified by riboflavin, enhanced the Pt(IV) reduction rate. Conclusion: This study reported for the first time the ability of an anaerobic granular sludge to reduce Pt(IV) to elemental Pt(0) nanoparticles. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Cu-modified Co3O4 nanosheets were designed and fabricated via a facile two-step process by a simple microwave-assisted reaction to synthesise Co3O4 sheets, followed by chemically reducing copper ion on Co3O4 sheets. The structures and morphologies of the obtained sheet-like Cu-modified Co3O4 nanomaterials were characterised by X-ray diffractometer, scanning electron microscopy, and transmission electron microscopy. As the anode materials for the lithium-ion battery applications, the Cu-modified Co3O4 nanosheet electrode delivered an initial discharge capacity of 1208 mAh g-1 and its initial coulombic efficiency was 82.24%, much higher than 74.8% for Co3O4 sheets. More importantly, a reversible capacity of ca. 600 mAh g-1 could be reached at a higher current density of 890 mA g-1. The enhanced electrochemical performance may be attributed the incorporated Cu as well as the porous structure and the sheet-like morphology of the Co3O4 active materials. [ABSTRACT FROM AUTHOR]

Abstract: A new series of Ln2+ complexes has been synthesized that overturns two previous generalizations in rare‐earth metal reduction chemistry: that amide ligands do not form isolable complexes of the highly reducing non‐traditional Ln2+ ions, and that yttrium is a good model for the late lanthanides in these reductive reactions. Reduction of Ln(NR2)3 (R=SiMe3) complexes in THF under Ar with M=K or Rb in the presence of 2.2.2‐cryptand (crypt) forms crystallographically characterizable [M(crypt)][Ln(NR2)3] complexes not only for the traditional Tm2+ ion and the configurational crossover ions, Nd2+ and Dy2+, but also for the non‐traditional Gd2+, Tb2+, Ho2+, and Er2+ ions. Crystallographic data as well as UV/Vis, magnetic susceptibility, and density functional theory studies are consistent with the accessibility of 4fn5d1 configurations for Ln2+ ions in this tris(silylamide) ligand environment. The Dy2+ complex, [K(crypt)][Dy(NR2)3], has a higher magnetic moment than previously observed for any monometallic complex: 11.67 μB. [ABSTRACT FROM AUTHOR]

The reduction ability of a N→Sn coordinated distannyne {LSn}2, where L is [C6H3‐2,6‐(Me2NCH2)2]– is tested towards organic molecules ethylene and cyclooctatetraene. These reactions provide the compound [{LSn}3SnH] (2), as the result of a hydride abstraction. DFT calculations suggest that compound 2 can be interpreted as highly covalently bonded {HSnI} and {(SnIL)3} fragments. While the reduction of the C=C bond is not observed in the reaction of 1 with organic molecules, the reducing ability of 1 is observed in the reaction with inorganic SnO. Complex 1 is able to reduce SnO and the organotin(II) oxide {LSn}2O (3) is obtained. Moreover, compound 3 is able to coordinate an excess of SnO to yield the organotin(II)–tin(II)–oxo cluster L4Sn10O8 (4). [ABSTRACT FROM AUTHOR]

Tens of micrometers long metallic Ni submicrowires with a diameter of approximately 200 nm are prepared by a chemical reduction method under a magnetic field. Fe-doped Ni2P nanosheets are then in situ grown on Ni submicrowires by a simple wet-chemical reaction followed by a low-temperature phosphorization process. The (Ni0.87Fe0.13)2P-Ni composite exhibits the highest catalytic activity toward oxygen evolution reaction in alkaline solution among all the as-prepared (Ni1-xFex)2P-Ni catalysts, delivering a current density of 10 mAcm-2 at an overpotential of only 257 mV and keeping high stability over 10 h electrolysis. These exceptional activities are attributed to the unique structure combining metallic Ni submicrowires as good electronically conductive substrate and the in situ grown Fedoped Ni2P nanosheets. Specifically, Fe incorporation leads to strong electron interactions between Ni, Fe, and P, fast reaction kinetics, small charge-transfer resistance, and a large electrochemical surface area, which are responsible for the excellent catalytic performance. [ABSTRACT FROM AUTHOR]

Abstract: Silver staining, which exploits the special bioaffinity and the chromogenic reduction of silver ions, is an indispensable visualization method in biology. It is a most popular method for in‐gel protein detection. However, it is limited by run‐to‐run variability, background staining, inability for protein quantification, and limited compatibility with mass spectroscopic (MS) analysis; limitations that are largely attributed to the tricky chromogenic visualization. Herein, we reported a novel water‐soluble fluorogenic Ag+ probe, the sensing mechanism of which is based on an aggregation‐induced emission (AIE) process driven by tetrazolate‐Ag+ interactions. The fluorogenic sensing can substitute the chromogenic reaction, leading to a new fluorescence silver staining method. This new staining method offers sensitive detection of total proteins in polyacrylamide gels with a broad linear dynamic range and robust operations that rival the silver nitrate stain and the best fluorescent stains. [ABSTRACT FROM AUTHOR]

ABSTRACT: Superheated water (shH2O) is investigated as a process aid in conventional aliphatic polyamide (PA) systems. The polymers investigated include PA 6 (PA6), PA 6,6 (PA66), PA 6,12 (PA612), and PA 12 (PA12). It is shown that the PA melting and crystallization temperatures are significantly reduced when exposed to shH2O. For example, the melting temperature of PA6 is depressed from 206 to 153 °C in the presence of shH2O. A relationship between amide group density and thermal transition temperature reduction is observed. Processing these materials in shH2O has led to a variety of materials ranging from low‐density foams to higher density locally anisotropic foamed morphologies. In situ observations of PAs melting in the presence of shH2O are performed using a specially designed reactor. Results from these experiments are used to estimate the diffusion coefficient of shH2O in PA6. Finally, low‐temperature extrusion is performed with PA6 and shH2O at temperatures as low as 180 °C and mixture viscosity is estimated. A 20‐fold depression in the melt viscosity of PA6 is observed at 240 °C with shH2O. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 803–813 [ABSTRACT FROM AUTHOR]

Abstract: Transmetallation of Pb(OAc)4 with R2Hg (1), followed by treatment with HCl in Et2O, provided RPbCl3 (2), the first kinetically stabilized monoorganolead trihalide that resists reductive elimination under ambient conditions. The kinetic stabilisation relies on an intramolecularly coordinating O‐donor substituent (R=6‐Ph2P(O)‐Ace‐5‐). The gram‐scale preparation of 2 was key for the synthesis of unsymmetrically substituted diaryllead dichlorides RR′PbCl2 (3 a, R′=Ph; 3 b, R′=4‐MeOC6H4; 3 c, R′=4‐Me2NC6H4). [ABSTRACT FROM AUTHOR]

Abstract: For the comprehensive utilization of coal gangue, acid‐leached coal gangue was used as silicon source and part of carbon source, low ash anthracite and degreasing cotton were added respectively as supplementary carbon source, SiC and SiC fiber were prepared by carbothermal reduction method accordingly. The results show that the main components in leached coal gangue are amorphous SiO2 and carbon, which are suitable for the synthesis of SiC as raw materials. The synthesis temperature and holding time have important influence on the synthesis of SiC, and the optimum synthesis parameters for SiC are at 1550°C for 4 hours; under this condition, the yield of SiC is 78.27%, and the specific surface area is 6750 cm2/g. The results show that the resulting products are essentially composed of β‐SiC with a minor amount of α‐SiC. Besides, based on the carbon fiber transformation method, SiC fiber was prepared by using leached coal gangue and degreasing cotton as raw materials. Therefore, it can be concluded that leached coal gangue is a very effective and inexpensive source for preparing SiC, and more importantly, this work has important economic and social significance to realize waste recycling and control pollution. [ABSTRACT FROM AUTHOR]

Calcium ferrite (CF) is the significant liquid phase for fluxed sinters, which are the main iron‐bearing materials charged into a blast furnace. The isothermal reduction kinetics of CaO–Fe2O3 (0, 2, 4, and 8 wt%)–Al2O3 (CF, CF2A, CF4A, and CF8A) by CO at 1073, 1123, 1173, and 1223 K are investigated by thermogravimetric analysis in this study. Results indicate that temperature exerts more influence on the reduction degree of ternary CaO–Fe2O3–Al2O3 system than alumina content. The reduction processes of CF, CF2A, CF4A, and CF8A are mainly expressed as a typical two‐stage reaction. The apparent activation energies of the reduction of CF, CF2A, CF4A, and CF8A are 43.6, 97.9, 87.7, and 82.9 kJ mol−1, respectively, based on the model‐free method. According to Sharp analysis, the reduction of CF is described by the Avrami‐Erofeev equation with 2D reaction, that of CF2A and CF4A is expressed initially with 2D reaction and then by the 2D phase boundary controlled reaction, and that of CF8A is controlled by 3D reaction. [ABSTRACT FROM AUTHOR]

Abstract: Nanoparticles (NPs) are actively investigated for their efficient use in catalysis, but their means of synthesis is a key factor influencing their catalytic properties owing to surface coverage with byproducts. Here, neutral electron‐ and hydride‐rich late transition metal organometallics are compared for the synthesis of late transition metal NPs in the presence of poly(vinylpirolidone) (PVP). In particular, the effect of electron‐reservoir donors, hydride‐reservoir donors, and electron‐rich dimers yielding NPs electrostatically stabilized by cationic organometallics are compared in terms of NP size and catalytic efficiency. The catalytic reactions scrutinized with excellent results include 4‐nitrophenol reduction to 4‐aminophenol by NaBH4 for the AuNPs and PdNPs, and Suzuki–Miyaura reactions for the PdNPs. The nature of the reductant has more influence on the NP size in the case of AuNPs than PdNPs, and the best NP catalysts are obtained with hydride‐reservoir complexes as reductants. The less bulky hydride donors are superior, with the complex [CoCp(ŋ4‐C5H6)] (Cp=ŋ5‐C5H5) giving the NPs with the best catalyst efficiencies for both reactions. Protection of the NP cores by the organometallic sandwich salt is found to be the key to catalytic efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Herein, we report the preparation of a heterogeneous, efficient, and recyclable ceria nanosphere (NS) catalyst, which was prepared by hydrothermal synthesis with oxalic acid as a capping agent. The morphology and thermal stability of the catalyst were studied by using SEM, XRD, and thermogravimetric analysis (TGA). This nanoceria catalyst was used for the chemoselective hydrogenation of deactivated α‐keto amides by using NaBH4. This reaction did not work in the absence of the nanoceria catalyst. A series of substituted hydroxy amides were prepared in very good yields with low catalyst loading. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the impact of the defects/defect density of electrocatalysts on the activity in the triiodide (I3−) reduction reaction of dye‐sensitized solar cells (DSSCs) is indispensable for the design and construction of high‐efficiency counter electrodes (CEs). Active‐site‐enriched selenium‐doped graphene (SeG) was crafted by ball‐milling followed by high‐temperature annealing to yield abundant edge sites and fully activated basal planes. The density of defects within SeG can be tuned by adjusting the annealing temperature. The sample synthesized at an annealing temperature of 900 °C exhibited a superior response to the I3− reduction with a high conversion efficiency of 8.42 %, outperforming the Pt reference (7.88 %). Improved stability is also observed. DFT calculations showed the high catalytic activity of SeG over pure graphene is a result of the reduced ionization energy owing to incorporation of Se species, facilitating electron transfer at the electrode–electrolyte interface. [ABSTRACT FROM AUTHOR]

Iron oxides (Fe2O3, Fe3O4) are highly desirable for electromagnetic (EM) microwave absorption applications because of their high magnetization, low toxicity and good magnetic loss. Herein, we repot an effective strategy to improve the reflection loss (RL) of iron oxides‐based materials via a delicate design of distinctive hybrid nanostructures, where uniform magnetite (Fe3O4) hollow nanoflowers organized from ultrathin nanosheets are supported on the reduced graphene oxide (rGO) matrix (MHF‐rGO). The designed MHF‐rGO exhibits excellent microwave absorption performance with a low RL of −53.3 dB at 4.96 GHz and a wide bandwidth of 5.68 GHz (< − 10 dB). The top level microwave absorption properties are associated with the high surface areas, ultrathin nanosheets and hollow structures of magnetic Fe3O4 nanoflowers, which present a good synergetic role with lightweight rGO. Furthermore, the controllable permittivity in MHF‐rGO is developed by adjusting the rGO content, which can balance the permeability to obtain a good impedance matching. This study paves an effective way to improve and extend the microwave absorption performances of iron oxides‐based materials through a delicate hybrid nanostructures design strategy. [ABSTRACT FROM AUTHOR]

Barrier height of AlGaN/GaN transistor is lowered by the quantum coupling of hot electrons with large transverse energy via electro‐thermal effect. The coupling effectively raises the quantized levels of hot electrons, changes the electron density of the two‐dimensional electron gas, and consequently decreases the source drain current of the transistor. Based on the theory of quantum coupling of hot electrons, the current reduction is successfully modeled. The model is able to explain the effect of gate voltage, device temperature, gate length, gate metals, passivation, field‐plate structure, traps, and electron‐phonon interaction on current reduction. It also predicts a relative decrease of 4.6% in the source drain current caused by the quantum coupling at moderately low electron temperature of 1771 K. [ABSTRACT FROM AUTHOR]

Abstract: A facile strategy is reported for the synthesis of Fe/Co mixed metal oxide nanoparticles supported on, and embedded inside, high purity oxidized multiwalled carbon nanotubes (MWCNTs) of narrow diameter distribution as effective bifunctional catalysts able to reversibly drive the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) in alkaline solutions. Variation of the Fe/Co ratio resulted in a pronounced trend in the bifunctional ORR/OER activity. Controlled synthesis and in‐depth characterization enabled the identification of an optimal Fe/Co composition, which afforded a low OER/OER reversible overvoltage of only 0.831 V, taking the OER at 10 mA cm−2 and the ORR at −1 mA cm−2. Importantly, the optimal catalyst with a Fe/Co ratio of 2:3 exhibited very promising long‐term stability with no evident change in the potential for both the ORR and the OER after 400 charge/discharge (OER/ORR) cycles at 15 mA cm−2 in 6  m KOH. Moreover, detailed investigation of the structure, size, and phase composition of the mixed Fe/Co oxide nanoparticles, as well as their localization (inside of or on the surface of the MWCNTs) revealed insight of the possible contribution of the individual catalyst components and their synergistic interaction in the catalysis. [ABSTRACT FROM AUTHOR]

Abstract: The reduction of CO2 is a promising route to produce valuable chemicals or fuels and create C‐neutral resource cycles. Many different approaches to CO2 reduction have been investigated, but the ability of vacuum UV (VUV) irradiation to cleave C−O bonds has remained largely unexplored for use in processes that convert CO2 into useful products. Compared with other photo‐driven CO2 conversion processes, VUV‐initiated CO2 reduction can achieve much greater conversion under common photochemical reaction conditions when H2 and non‐reducible oxides are present. Infrared spectroscopy provides evidence for a chain reaction initiated by VUV‐induced CO2 splitting, which is enhanced in the presence of H2 and silica. When the reaction is carried out in the presence of silica or alumina surfaces, CO yields are increased and CH4 is formed as the only other detected product. CH4 production is not promoted by traditional photocatalysts such as TiO2 under these conditions. Assuming improvements in lamp and reactor efficiencies with scale up, or coupling with other available CO/CO2 hydrogenation techniques, these results reveal a potential, simple strategy by which CO2 could be valorized. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogenases catalyse nitrogen fixation to ammonia on a multinuclear Fe‐Mo centre, but their mechanism and particularly the order of proton and electron transfer processes that happen during the catalytic cycle is still unresolved. Recently, a unique biomimetic mononuclear iron model was developed using tris(phosphine)borate (TPB) ligands that was shown to convert N2 into NH3. Herein, we present a computational study on the [(TPB)FeN2]− complex and describe its conversion into ammonia through the addition of electrons and protons. In particular, we tested the consecutive proton transfer on only the distal nitrogen atom or alternated protonation of the distal/proximal nitrogen. It is found that the lowest energy pathway is consecutive addition of three protons to the same site, which forms ammonia and an iron‐nitrido complex. In addition, the proton transfer step of complexes with the metal in various oxidation and spin states were tested and show that the pKa values of biomimetic mononuclear nitrogenase intermediates vary little with iron oxidation states. As such, the model gives several possible NH3 formation pathways depending on the order of electron/proton transfer, and all should be physically accessible in the natural system. These results may have implications for enzymatic nitrogenases and give insight into the catalytic properties of mononuclear iron centres. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical reduction of carbon dioxide is very much in the focus of interest today. Intensive research is carried out in leading laboratories trying to work out methods for making useful materials from this unwanted greenhouse gas using solar or wind power generated excess electric energy. In this work, electrochemical reduction experiments are carried out in homemade cells supplied with different metal electrodes. Electrolytes containing carbon dioxide absorbing components like monoethanolamine (MEA) or KHCO3, KOH, and K2CO3 solutions are used. Metal‐containing species were noticed in the used electrolytes after being in contact with the metal working electrodes. Therefore parallel to the electrochemical measurements, the metal components in the electrolyte were checked with atomic absorption methods for getting better insight into the nature of the electrode passivation. This paper attempts to compare the behavior of different electrode materials (copper, nickel) in CO2 capturing media, and investigate of the products of the electrolysis using Scanning Electrochemical Microscopy (SECM), Atomic Absorption Spectroscopy (AAS) and gas chromatography. [ABSTRACT FROM AUTHOR]

Abstract: The first catalytic inverse hydroboration of imines with N‐heterocyclic carbene (NHC) boranes has been realized by means of cooperative organocatalysis and photocatalysis. This catalytic combination provides a promising platform for promoting NHC‐boryl radical chemistry under sustainable and radical‐initiator‐free conditions. The highly important functional‐group compatibility and possible application in late‐stage hydroborations represent an important step forward to an enhanced α‐amino organoboron library. [ABSTRACT FROM AUTHOR]

Abstract: Herein, we report the synthesis, electrochemical, and computational evaluation of six 2‐substituted imidazolium bromides and six 2‐substituted imidazolium triflates. All final compounds were obtained in 2 or fewer synthetic steps from inexpensive starting materials and display a single, irreversible electrochemical reduction. The reduction potentials span a range greater than 1 V depending on the electron withdrawing power of the 2‐substituent. Imidazolium bromides such as Bn2(H)ImBr reduce with E1/2 = −2.70 V vs Fc/Fc+, whereas the electron‐withdrawing Br‐containing analog Bn2(Br)ImBr reduces at only −1.58 V vs Fc/Fc+. The reduction potential of imidazolium bromides obeys a linear free energy relationship to σm Hammett constants, whereas imidazolium triflates correlate better with the σp Hammett constants. These results indicate that the stabilizing effect of the 2‐substituent is anion‐sensitive, changing from induction to resonance upon exchanging bromide for triflate. Predicted electron affinities from density functional theory–optimized structures of imidazolium cations and reduced species more closely match experimental data for the triflates, suggesting that a triflate anion does not electronically perturb the imidazolium core as much as a bromide. Taken together, these data highlight the dual modularity of imidazolium salts by changing both 2‐substituent and anion. [ABSTRACT FROM AUTHOR]

Abstract: We report on a headspace gas chromatographic method for determining the content of 3‐chloro‐1,2‐propanediol in polyamideamine epichlorohydrin resin solution. It was based on quantitatively converting 3‐chloro‐1,2‐propanediol to formaldehyde by periodate oxidation in a closed headspace sample vial at a room temperature for 10 min, and then to methanol by borohydride reduction at 90°C for 40 min followed by the headspace gas chromatographic measurement. The results showed that the present method has an excellent measurement precision (relative standard deviation < 2.60%) and accuracy (recoveries from 96.4–102%) in 3‐chloro‐1,2‐propanediol analysis. The limit of quantitation was 0.031 mg/mL. It is simple and suitable for determining the 3‐chloro‐1,2‐propanediol content in polyamideamine epichlorohydrin resin solution. [ABSTRACT FROM AUTHOR]

KCC‐1/IL/Pd NPs can used as an excellent support for the synthesis of highly sparse homogeneous catalyst. KCC‐1 has high surface area that was functionalized with ionic liquid phase acting as the strong performers so that the Pd catalyst was well‐dispersed without aggregation on the framework of the KCC‐1/IL. This nano catalyst was specified by TGA, XRD, TEM, SEM, FT‐IR, and ICP. For reduction of 2‐nitroaniline and 4‐nitrophenol used from the KCC‐1/IL/Pd NPs as a green catalyst that showed excellent catalytic activities. Compared with the traditional substrate, KCC‐1 substantially increases protection and the accessibility of the nanoparticle sites due to its three dimensional hierarchical structure. [ABSTRACT FROM AUTHOR]

This paper reports the green and in situ preparation of Fe3O4@SiO2‐Ag magnetic nanocatalyst synthesized using safflower (Carthamus tinctorius L.) flower extract without the addition of any stabilizers or surfactants. The catalytic performance of the resulting nanocatalyst was examined for the reduction of 4‐nitrophenol (4‐NP), methylene blue (MB) and methyl orange (MO) in an environment‐friendly medium at room temperature. The main factors such as pH, temperature and amount of catalyst influencing the nanocatalyst performance were studied. The apparent rate constants for 4‐NP, MO and MB reduction were calculated, being 0.756 min−1, 0.064 s−1 and 0.09 s−1, respectively. The catalyst was recovered using an external magnet and reused several times with negligible loss of catalytic activity. The as‐synthesized nanoparticles were characterized using powder X‐ray diffraction, transmission electron microscopy, UV–visible, Fourier transform infrared and inductively coupled plasma atomic emission spectroscopies, dynamic light scattering and vibrating sample magnetometry. [ABSTRACT FROM AUTHOR]

Flash reduction of graphene oxide is an efficient method for producing high quality reduced graphene oxide under room temperature ambient conditions without the use of hazardous reducing agents (such as hydrazine and hydrogen iodide). The entire process is fast, low‐cost, and suitable for large‐scale fabrication, which makes it an attractive process for industrial manufacturing. Herein, we present a simple fabrication method for a flexible in‐plane graphene micro‐supercapacitor using flash light irradiation. All carbon‐based, monolithic supercapacitors with in‐plane geometry can be fabricated with simple flash irradiation, which occurs in only a few milliseconds. The thinness of the fabricated device makes it highly flexible and thus useful for a variety of applications, including portable and wearable electronics. The rapid flash reduction process creates a porous graphene structure with high surface area and good electrical conductivity, which ultimately results in high specific capacitance (36.90 mF cm−2) and good cyclic stability up to 8,000 cycles. [ABSTRACT FROM AUTHOR]

Abstract: N‐doped mesoporous carbons (NMCs) have drawn a lot of interest as alternative electrocatalysts to replace noble metals. The maximized surface areas endow NMCs substantially increased active sites and thus greatly promote the catalytically apparent performance. Herein, polydopamine (PDA) is employed to derive NMCs by a facile hard‐templating method. The newly‐developed NMC‐900 shows highly catalytic efficiency in oxygen reduction reaction (ORR), comparable to that of Pt/C and superb stability greatly surpassing Pt/C, attributed to its fascinating componential and structural merits. The componential‐favored graphitic N and pyridinic N afforded highly efficient and stable metal‐free active sites. The structurally large surface area (536 m2/g) and well‐aligned 3D mesoporous architecture provided sufficiently exposed active sites and unimpeded reaction channels for ORR. Both the good electrical conductivity and hydrophilic surface of NMC‐900 ensured an expedited ORR process. [ABSTRACT FROM AUTHOR]