bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vastly Enhanced BiVO4 Photocatalytic OER Performance by NiCoO2 as Cocatalyst
Authors: Palaniselvam Thangavelu , Shi Le , Mettela Gangaiah , Anjum Dalavar H. , Li Renyan , Katuri Krishna P. , Saikaly Pascal E. , Wang Peng 
Published: August 2017

AbstractHere, a simple and efficient preparation of NiCoO2 nanoparticle modified nanoporous bismuth vanadate (BiVO4) thin film and its application in photoelectrocatalytic (PEC) oxygen evolution reaction (OER) is demonstrated. The role of NiCoO2 in the composite electrode (BiVO4/NiCoO2) is twofold: OER cocatalyst and band structure modifier. It improves surface reaction kinetics for PEC OER and enhances charge separation efficiency simultaneously, which is believed to be a determining factor for the unprecedentedly high PEC OER performance of this BiVO4/NiCoO2 nanocomposite. The photocurrent density of 3.6 mA cm−2 at 1.23 V versus RHE in 0.1 m potassium phosphate buffered (pH = 7) electrolyte by BiVO4/NiCoO2 is three times that of BiVO4 and significantly higher than most literature values. The BiVO4/NiCoO2 nanocomposite shows/possess a high charge separation efficiency (ηsurface) of ≈72% as compared to only 23% for pure nanoporous BiVO4 at 1.23 V versus RHE, which demonstrates convincing role of NiCoO2 in the composite electrode. Both the excellent photocurrent density and great operational stability of this BiVO4/NiCoO2 nanocomposite makes it a promising photocatalytic material for practical applications.
Two‐Step Synthesis of Polysubstituted 6‐Nitroindoles under Flow Chemical and Microwave Conditions
Authors: Sampaolesi Susanna , Gabrielli Serena , Ballini Roberto , Palmieri Alessandro 
Published: August 2017

AbstractA new simple and efficient synthesis of 6‐nitroindoles, starting from N‐carboxylalkylpyrrole‐2‐carboxaldehydes and protected β‐nitro ketones, has been developed. The method involves two distinct domino processes, respectively performed under flow chemical conditions and microwave irradiation. 6‐Nitroindoles were produced in good to excellent overall yields.magnified image
Steric‐Hindrance Modulation toward High‐Performance 1,3‐Bis(thieno[3,4‐b]thiophen‐6‐yl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione‐Based Polymer Solar Cells with Enhanced Open‐Circuit Voltage
Authors: Zhang Cheng , Zhou Zichun , Wu Hao , Liu Feng , Zhu Xiaozhang 
Published: August 2017

AbstractSolution‐processed bulk‐heterojunction polymer solar cells (PSCs) are indispensable in photovoltaics. π‐Conjugated donor–acceptor copolymers as electron donors have become the cornerstone as the most intensively studied topic in this field. Thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) is one of the most commonly used electron‐withdrawing moieties. Based on TPD, a new building block, 1,3‐bis(thieno[3,4‐b]thiophen‐6‐yl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (TBTT), is designed and a novel low‐bandgap TPD‐copolymer is developed with a power conversion efficiency (PCE) up to 7.5% with a low open‐circuit voltage (Voc) of 0.633 V when utilizing PC71BM as electron acceptor. To promote the performance of TBTT‐based polymers, four conjugated copolymers are designed and synthesized based on TBTT and benzodithiophene (BDT) building blocks by regulating their steric hindrance with side alkyl chains on BDT moiety. PSCs based on polymer P4 with an additional n‐hexyl side chain blended with PC71BM deliver a high PCE of 9.1% with a Voc of 0.78 V increased by 24%, which is among the highest in TPD‐based polymers. The study provides new insights into the molecular design and synthesis of high‐performance photovoltaic materials.
Triboelectrification‐Enabled Self‐Charging Lithium‐Ion Batteries
Authors: Zhao Kun , Yang Ya , Liu Xi , Wang Zhong Lin 
Published: August 2017

AbstractLi‐ion batteries as energy storage devices need to be periodically charged for sustainably powering electronic devices owing to their limited capacities. Here, the feasibility of utilizing Li‐ion batteries as both the energy storage and scavenging units is demonstrated. Flexible Li‐ion batteries fabricated from electrospun LiMn2O4 nanowires as cathode and carbon nanowires as anode enable a capacity retention of 90% coulombic efficiency after 50 cycles. Through the coupling between triboelectrification and electrostatic induction, the adjacent electrodes of two Li‐ion batteries can deliver an output peak voltage of about 200 V and an output peak current of about 25 µA under ambient wind‐induced vibrations of a hexafluoropropene–tetrafluoroethylene copolymer film between the two Li‐ion batteries. The self‐charging Li‐ion batteries have been demonstrated to charge themselves up to 3.5 V in about 3 min under wind‐induced mechanical excitations. The advantages of the self‐charging Li‐ion batteries can provide important applications for sustainably powering electronics and self‐powered sensor systems.
A Multisite Strategy for Enhancing the Hydrogen Evolution Reaction on a Nano‐Pd Surface in Alkaline Media
Authors: Liao Hanbin , Wei Chao , Wang Jingxian , Fisher Adrian , Sritharan Thirumany , Feng Zhenxing , Xu Zhichuan J. 
Published: August 2017

AbstractThe hydrogen evolution reaction (HER) on a noble metal surface in alkaline media is more sluggish than that in acidic media due to the limited proton supply. To promote the reaction, it is necessary to transform the alkaline HER mechanism via a multisite catalyst, which has additional water dissociation sites to improve the proton supply to an optimal level. Here, this study reports a top‐down strategy to create a multisite HER catalyst on a nano‐Pd surface and how to further fine‐tune the areal ratio of the water dissociation component to the noble metal surface in core/shell‐structured nanoparticles (NPs). Starting with Pd/Fe3O4 core/shell NPs, electrochemical cycling is used to tune the coverage of iron (oxy)hydroxide on a Pd surface. The alkaline HER activity of the core/sell Pd/FeOx(OH)2−2x NPs exhibits a volcano‐shaped correlation with the surface Fe species coverage. This indicates an optimum coverage level where the rates of both the water dissociation step and the hydrogen formation step are balanced to achieve the highest efficiency. This multisite strategy assigns multiple reaction steps to different catalytic sites, and should also be extendable to other core/shell NPs to optimize their HER activity in alkaline media.
Optimized Bicompartment Two Solution Cells for Effective and Stable Operation of Li–O2 Batteries
Authors: Kwak Won‐Jin , Jung Hun‐Gi , Aurbach Doron , Sun Yang‐Kook 
Published: August 2017

AbstractLithium–oxygen batteries are in fact the only rechargeable batteries that can rival internal combustion engines, in terms of high energy density. However, they are still under development due to low‐efficiency and short lifetime issues. There are problems of side reactions on the cathode side, high reactivity of the Li anode with solution species, and consumption of redox mediators via reactions with metallic lithium. Therefore, efforts are made to protect/block the lithium metal anode in these cells, in order to mitigate side reactions. However, new approach is required in order to solve the problems mentioned above, especially the irreversible reactions of the redox mediators which are mandatory to these systems with the Li anode. Here, optimized bicompartment two solution cells are proposed, in which detrimental crossover between the cathode and anode is completely avoided. The Li metal anode is cycled in electrolyte solution containing fluorinated ethylene carbonate, in which its cycling efficiency is excellent. The cathode compartment contains ethereal solution with redox mediator that enables oxidation of Li2O2 at low potentials. The electrodes are separated by a solid electrolyte membrane, allowing free transport of Li ions. This approach increases cycle life of lithium oxygen cells and their energy efficiency.
Role of Ionic Functional Groups on Ion Transport at Perovskite Interfaces
Authors: Liu Yao , Renna Lawrence A. , Thompson Hilary B. , Page Zachariah A. , Emrick Todd , Barnes Michael D. , Bag Monojit , Venkataraman D. , Russell Thomas P. 
Published: August 2017

AbstractHybrid organic/inorganic perovskite solar cells are invigorating the photovoltaic community due to their remarkable properties and efficiency. However, many perovskite solar cells show an undesirable current–voltage (I–V) hysteresis in their forward and reverse voltage scans, working to the detriment of device characterization and performance. This hysteresis likely arises from slow ion migration in the bulk perovskite active layer to interfaces which may induce charge trapping. It is shown that interfacial chemistry between the perovskite and charge transport layer plays a critical role in ion transport and I–V hysteresis in perovskite‐based devices. Specifically, phenylene vinylene polymers containing cationic, zwitterionic, or anionic pendent groups are utilized to fabricate charge transport layers with specific interfacial ionic functionalities. The interfacial‐adsorbing boundary induced by the zwitterionic polymer in contact with the perovskite increases the local ion concentration, which is responsible for the observed I–V hysteresis. Moreover, the ion adsorbing properties of this interface are exploited for perovskite‐based memristors. This fundamental study of I–V hysteresis in perovskite‐based devices introduces a new mechanism for inducing memristor behavior by interfacial ion adsorption.
High‐Performance and Breathable Polypyrrole Coated Air‐Laid Paper for Flexible All‐Solid‐State Supercapacitors
Authors: Chen Yuanxun , Cai Kefeng , Liu Congcong , Song Haijun , Yang Xiaowei 
Published: August 2017

AbstractHigh‐performance, breathable, conductive, and flexible polypyrrole (PPy) coated paper electrodes are prepared by an interfacial polymerization method using air‐laid paper as a substrate. Owing to the synergistic effect of superior electrical conductivity, high wettability, and the porous architecture, the prepared electrode not only shows an outstanding specific capacitance and rate abilities (3100 and 2579 mF cm−2 at 1 and 20 mA cm−2 for a PPy coated paper electrode), but also exhibits excellent flexibility, wearability, and breathability. Based on these superior features, an all‐solid‐state supercapacitor assembled with the PPy coated paper electrodes shows an outstanding energy density of 62.4 µW h cm−2, remarkable air permeability and excellent flexibility to sustain various deformations. Furthermore, large‐scale fabrication of conductive flexible paper electrode can be easily achieved through this method. Therefore, this work offers a new vision for flexible energy storage.
Risk factors and a prognostic model for postsplenectomy survival in myelofibrosis
Authors: Tefferi Ayalew , Mudireddy Mythri , Gangat Naseema , Hanson Curtis A. , Ketterling Rhett P. , Pardanani Animesh , Nagorney David M. 
Published: August 2017

AbstractPalliative treatment in myelofibrosis (MF) includes transfusion support, JAK2 inhibitors, involved field radiotherapy and splenectomy. To assist in selecting patients who are likely to benefit from splenectomy, we looked into risk factors for postsplenectomy survival, in 120 consecutive cases (median age 66 years); at the time of splenectomy, 61% displayed red cell transfusion need, 49% platelet count <100 × 10(9)/L, 25% leukocyte count >25 × 10(9)/L, 60% constitutional symptoms and 13% circulating blasts ≥5%; dynamic international prognostic scoring system risk categories were 21% high, 55% intermediate‐2, 21% intermediate‐1 and 3% low. Among informative cases, karyotype was abnormal in 60% and driver mutational status was JAK2 75%, CALR 15%, MPL 4% and triple‐negative 6%. At median follow‐up of 1.3 years, from time of splenectomy, 95 (79%) deaths and 30 (25%) leukemic transformations were recorded. Median postsplenectomy survival was 1.5 years; in multivariable analysis, survival was adversely affected by age >65 years, transfusion need, leukocyte count >25 × 10(9)/L and circulating blasts ≥5%; these variables were subsequently used to devise an HR‐weighted scoring system with high (3‐4 risk factors), intermediate (2 risk factors) and low (0‐1 risk factors) risk categories; the corresponding postsplenectomy median survivals were 0.3 (HR 5.9, 95% CI 3.2‐11.0), 1.3 (HR 2.9, 95% CI 1.8‐4.6) and 2.9 years. Postsplenectomy survival was not affected by driver mutational status or occurrence of leukemic transformation. Leukemia‐free survival was predicted by very high risk karyotype. The observations from the current study might help identify appropriate candidates for splenectomy in MF.
Highly Selective Artificial Potassium Ion Channels Constructed from Pore‐Containing Helical Oligomers
Authors: Lang Chao , Deng Xiaoli , Yang Feihu , Yang Bing , Wang Wei , Qi Shuaiwei , Zhang Xin , Zhang Chenyang , Dong Zeyuan , Liu Junqiu 
Published: August 2017

AbstractPotassium ion channels specifically transport K+ ions over Na+ ions across a cell membrane. A queue of four binding sites in the K+ channel pore plays significant roles during highly selective conduction. A kind of aromatic helical oligomer was synthesized that can selectively bind K+ over Na+. By aromatic stacking of helical oligomers, a type of artificial K+ channels with contiguous K+ binding sites was constructed. Such artificial channels exhibited exceptionally high K+/Na+ selectivity ratios during transmembrane ion conduction.
A Suite of “Minimalist” Photo‐Crosslinkers for Live‐Cell Imaging and Chemical Proteomics: Case Study with BRD4 Inhibitors
Authors: Pan Sijun , Jang Se‐Young , Wang Danyang , Liew Si Si , Li Zhengqiu , Lee Jun‐Seok , Yao Shao Q. 
Published: August 2017

AbstractAffinity‐based probes (AfBPs) provide a powerful tool for large‐scale chemoproteomic studies of drug–target interactions. The development of high‐quality probes capable of recapitulating genuine drug–target engagement, however, could be challenging. “Minimalist” photo‐crosslinkers, which contain an alkyl diazirine group and a chemically tractable tag, could alleviate such challenges, but few are currently available. Herein, we have developed new alkyl diazirine‐containing photo‐crosslinkers with different bioorthogonal tags. They were subsequently used to create a suite of AfBPs based on GW841819X (a small molecule inhibitor of BRD4). Through in vitro and in situ studies under conditions that emulated native drug–target interactions, we have obtained better insights into how a tag might affect the probe's performance. Finally, SILAC‐based chemoproteomic studies have led to the discovery of a novel off‐target, APEX1. Further studies showed GW841819X binds to APEX1 and caused up‐regulation of endogenous DNMT1 expression under normoxia conditions.
Atomic‐Level Insight into Optimizing the Hydrogen Evolution Pathway over a Co1‐N4 Single‐Site Photocatalyst
Authors: Cao Yuanjie , Chen Si , Luo Qiquan , Yan Huan , Lin Yue , Liu Wei , Cao Linlin , Lu Junling , Yang Jinlong , Yao Tao , Wei Shiqiang 
Published: August 2017

AbstractKnowledge of the photocatalytic H2 evolution mechanism is of great importance for designing active catalysts toward a sustainable energy supply. An atomic‐level insight, design, and fabrication of single‐site Co1‐N4 composite as a prototypical photocatalyst for efficient H2 production is reported. Correlated atomic characterizations verify that atomically dispersed Co atoms are successfully grafted by covalently forming a Co1‐N4 structure on g‐C3N4 nanosheets by atomic layer deposition. Different from the conventional homolytic or heterolytic pathway, theoretical investigations reveal that the coordinated donor nitrogen increases the electron density and lowers the formation barrier of key Co hydride intermediate, thereby accelerating H–H coupling to facilitate H2 generation. As a result, the composite photocatalyst exhibits a robust H2 production activity up to 10.8 μmol h−1, 11 times higher than that of pristine counterpart.
A Simple Route to Calcium and Strontium Hydride Clusters
Authors: Maitland Brant , Wiesinger Michael , Langer Jens , Ballmann Gerd , Pahl Jürgen , Elsen Holger , Färber Christian , Harder Sjoerd 
Published: August 2017

AbstractThe first strontium hydride complex has been obtained by simply treating Sr[N(SiMe3)2]2 with PhSiH3 in the presence of PMDTA. The Sr complex Sr6H9[N(SiMe3)2]3⋅(PMDTA)3 crystallizes as an “inverse cryptand”: an interstitial H− is surrounded by a Sr6H84+ cage decorated with amide and PMDTA ligands. The analogous Ca complex could also be obtained and both retain their solid‐state structures in solution: 1H NMR spectra in C6D6 show two doublets and one nonet (4:4:1). Up to 90 °C, no coalescence is observed. The Ca cluster was investigated by DFT calculations and shows atypically low charges on Ca (+1.14) and H (−0.59) which signifies an unexpectedly low ionicity. AIM analysis shows hydride⋅⋅⋅hydride bond paths with considerable electron densities in the bond critical point. The clusters thermally decompose into larger, undefined, metal hydride aggregates.
Highly Regioselective Alkylation of Hexabenzocoronenes: Fundamental Insights into the Covalent Chemistry of Graphene
Authors: Holzwarth Johannes , Amsharov Konstantin Yu. , Sharapa Dmitry I. , Reger David , Roshchyna Kateryna , Lungerich Dominik , Jux Norbert , Hauke Frank , Clark Timothy , Hirsch Andreas 
Published: August 2017

AbstractHexa‐peri‐hexabenzocoronides (HBC) was successfully used as a model system for investigating the complex mechanism of the reductive functionalization of graphene. The well‐defined molecular HBC system enabled deeper insights into the mechanism of the alkylation of reductively activated nanographenes. The separation and complete characterization of alkylation products clearly demonstrate that nanographene functionalization proceeds with exceptionally high regio‐ and stereoselectivities on the HBC scaffold. Experimental and theoretical studies lead to the conclusion that the intact basal graphene plane is chemically inert and addend binding can only take place at either preexisting defects or close to the periphery.
Asymmetric Synthesis of Tertiary Alcohols and Thiols via Nonstabilized Tertiary α‐Oxy‐ and α‐Thio‐Substituted Organolithium Species
Authors: Pulis Alexander P. , Varela Ana , Citti Cinzia , Songara Pradip , Leonori Daniele , Aggarwal Varinder K. 
Published: August 2017

AbstractNonstabilized α‐O‐substituted tertiary organolithium species are difficult to generate, and the α‐S‐substituted analogues are configurationally unstable. We now report that they can both be generated easily and trapped with a range of electrophiles with high enantioselectivity, providing ready access to a range of enantioenriched tertiary alcohols and thiols. The configurational stability of the α‐S‐organolithium species was enhanced by using a less coordinating solvent and short reaction times.
Reductive Decarboxylative Alkynylation of N‐Hydroxyphthalimide Esters with Bromoalkynes
Authors: Huang Liangbin , Olivares Astrid M. , Weix Daniel J. 
Published: August 2017

AbstractA new method for the synthesis of terminal and internal alkynes from the nickel‐catalyzed decarboxylative coupling of N‐hydroxyphthalimide esters and bromoalkynes is presented. This reductive cross‐electrophile coupling is the first to use a C(sp)−X electrophile, and appears to proceed via an alkynylnickel intermediate. The internal alkyne products are obtained in yields of 41–95 % without the need for a photocatalyst, light, or a strong oxidant. The reaction displays a broad scope of carboxylic acid and alkyne coupling partners, and can tolerate an array of functional groups, including carbamate NH, halogen, nitrile, olefin, ketone, and ester moieties. Mechanistic studies suggest that this process does not involve an alkynylmanganese reagent and instead proceeds through nickel‐mediated bond formation.
A Convenient Route to Mixed Pnictogenylboranes
Authors: Hegen Oliver , Marquardt Christian , Timoshkin Alexey Y. , Scheer Manfred 
Published: August 2017

AbstractWe report on the synthesis and characterization of mixed pnictogenylboranes. The substitution of the Lewis base SMe2 in (OC)5W–PH2BH2–SMe2 (2) by different pnictogenylboranes ER2BH2–LB (E=P, As, Sb) leads to the Lewis acid/base stabilized butane analogue (OC)5W–PH2BH2ER2BH2–LB (3 a, b: E=P; R=H, SiMe3; LB=NMe3; 4 a, b: E=As; R=H, SiMe3; LB=NMe3; 5: E=Sb; R=SiMe3; LB=NHCMe). All of these compounds were characterized by single‐crystal X‐ray structure analysis, mass spectrometry, NMR, and IR spectroscopy. In addition, the very unstable phosphanylborane chain PH2BH2PH2BH2–NMe3 (1) was synthesized. DFT calculations provide insight into the thermodynamics of these reactions.
In situ electrical resistance and X‐ray tomography study of copper–tin polymer composites during thermal annealing
Authors: Yang Qing , Beers Megan Hoarfrost , Zheng Min , Lloyd Richard , Gao Ting , Parkinson Dilworth 
Published: August 2017

ABSTRACTIn situ electrical conductivity and X‐ray tomography experiments are conducted on a conductive polymer composite containing polyvinylidene fluoride (PVDF) copolymer, copper (Cu), and tin (Sn) during thermal annealing. During annealing, the electrical resistivity drops by an order of magnitude, while X‐ray tomography, electron microscopy, and spectroscopy results show increasingly homogeneous dispersion of Sn in the conductive filler network, accompanied by the formation of Cu–Sn intermetallic around Cu and Sn particles. This study provides detailed insight into the morphological origins of the beneficial effect of thermal annealing on the electrical properties of conductive composites containing low melting metal fillers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45399.
Multilayer structures based on annealed electrospun biopolymer coatings of interest in water and aroma barrier fiber‐based food packaging applications
Authors: Cherpinski Adriane , Torres‐Giner Sergio , Cabedo Luis , Méndez Jose Alberto , Lagaron Jose M. 
Published: August 2017

ABSTRACTIn this research work, for the first time, a fiber‐based packaging material was coated by annealed electrospun ultrathin fibers of poly(3‐hydroxybutyrate), poly(vinyl alcohol), and polylactide. The resultant mono‐ and multilayer structures self‐adhered to the paper substrate and were characterized in terms of morphology, optical, and barrier properties. Additionally, the use of a static flat plate and rotating mandrel collector as well as the application of different electrospinning deposition times were analyzed. The thermally treated electrospun biopolymers yielded totally transparent films while, due to the opaque nature of the uncoated paper substrate, the developed packaging materials were also opaque but with a glossier surface finish provided by the bioplastic coating. The annealed films obtained from random electrospun fibers, that is, the mats of ultrathin fibers collected on the static plate, presented higher transparency and thickness and also enhanced barrier performance. On the overall, the developed annealed electrospun biopolymer coatings resulted in a significant improvement of the paper barrier properties to water and limonene vapors, being the paper/poly(vinyl alcohol)/poly(3‐hydroxybutyrate) film the best performing multilayer packaging structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45501.