bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unconventional Route to Oxygen‐Vacancy‐Enabled Highly Efficient Electron Extraction and Transport in Perovskite Solar Cells
Authors: Wang Bing , Zhang Meng , Cui Xun , Wang Zewei , Rager Matthew , Yang Yingkui , Zou Zhigang , Wang Zhong Lin , Lin Zhiqun 
Published: October 2019

AbstractThe ability to effectively transfer photoexcited electrons and holes is an important endeavor toward achieving high‐efficiency solar energy conversion. Now, a simple yet robust acid‐treatment strategy is used to judiciously create an amorphous TiO2 buffer layer intimately situated on the anatase TiO2 surface as an electron‐transport layer (ETL) for efficient electron transport. The facile acid treatment is capable of weakening the bonding of zigzag octahedral chains in anatase TiO2, thereby shortening staggered octahedron chains to form an amorphous buffer layer on the anatase TiO2 surface. Such amorphous TiO2‐coated ETL possesses an increased electron density owing to the presence of oxygen vacancies, leading to efficient electron transfer from perovskite to TiO2. Compared to pristine TiO2‐based devices, the perovskite solar cells (PSCs) with acid‐treated TiO2 ETL exhibit an enhanced short‐circuit current and power conversion efficiency.
Reversible Thermochromism and Strong Ferromagnetism in Two‐Dimensional Hybrid Perovskites
Authors: Sun Bing , Liu Xiao‐Fei , Li Xiang‐Yang , Cao Yang , Yan Ze , Fu Lin , Tang Nujiang , Wang Qiang , Shao Xiangfeng , Yang Dezheng , Zhang Hao‐Li 
Published: October 2019

AbstractTwo‐dimensional (2D) hybrid perovskites have shown many attractive properties associated with their soft lattices and multiple quantum well structure. Herein, we report the synthesis and characterization of two new multifunctional 2D hybrid perovskites, (PED)CuCl4 and (BED)2CuCl6, which show reversible thermochromic behavior, dramatic temperature‐dependent conductivity change, and strong ferromagnetism. Upon temperature change, the (PED)CuCl4 and (BED)2CuCl6 crystals exhibit a reversible color change between yellow and red‐brown. The associated structural changes were monitored by in situ temperature‐dependent powder X‐ray diffraction (PXRD). The (BED)2CuCl6 exhibits superior thermal stability, with a thermochromic working temperature up to 443 K. The conductivity of (BED)2CuCl6 changes over six orders of magnitude upon temperature change. The 2D perovskites exhibit ferromagnetic properties with Curie temperatures around 13 K.
A [001]‐Oriented Hittorf's Phosphorus Nanorods/Polymeric Carbon Nitride Heterostructure for Boosting Wide‐Spectrum‐Responsive Photocatalytic Hydrogen Evolution from Pure Water
Authors: Zhu Yukun , Lv Chunxiao , Yin Zhuocheng , Ren Jun , Yang Xianfeng , Dong Chung‐Li , Liu Hongwei , Cai Rongsheng , Huang Yu‐Cheng , Theis Wolfgang , Shen Shaohua , Yang Dongjiang 
Published: October 2019

AbstractRed phosphorus is a promising photocatalyst with wide visible‐light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]‐oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h−1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]‐oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance.
An Unprecedented Kernel Growth Mode and Layer‐Number‐Odevity‐Dependent Properties in Gold Nanoclusters
Authors: Liao Lingwen , Wang Chengming , Zhuang Shengli , Yan Nan , Zhao Yan , Yang Ying , Li Jin , Deng Haiteng , Wu Zhikun 
Published: October 2019

AbstractKernel atoms of Au nanoclusters are packed layer‐by‐layer along the [001] direction with every full (001) monolayer composed of 8 Au atoms (Au8 unit) in nanoclusters with formula of Au8n+4(TBBT)4n+8 (n is the number of Au8 units; TBBTH=4‐tert‐butylbenzenelthiol). It is unclear whether the kernel atoms can be stacked in a defective‐layer way along the [001] direction during growth of the series of nanoclusters and how the kernel layer number affects properties. Now, a nanocluster is synthesized that is precisely characterized by mass spectrometry and single‐crystal X‐ray crystallography, revealing a layer stacking mode in which a half monolayer composed of 4 atoms (Au4 unit) is stacked on the full monolayer along the [001] direction. The size and the odevity of the kernel layer number influence the properties (polarity, photoluminescence) of gold nanoclusters. The obtained nanocluster extends the previous formula from Au8n+4(TBBT)4n+8 to Au4n+4(TBBT)2n+8 (n is the number of Au4 units).
Highly Selective Electrochemical Reduction of CO2 to Alcohols on an FeP Nanoarray
Authors: Ji Lei , Li Lei , Ji Xuqiang , Zhang Ya , Mou Shiyong , Wu Tongwei , Liu Qian , Li Baihai , Zhu Xiaojuan , Luo Yonglan , Shi Xifeng , Asiri Abdullah M. , Sun Xuping 
Published: October 2019

AbstractElectrochemical reduction of CO2 into various chemicals and fuels provides an attractive pathway for environmental and energy sustainability. It is now shown that a FeP nanoarray on Ti mesh (FeP NA/TM) acts as an efficient 3D catalyst electrode for the CO2 reduction reaction to convert CO2 into alcohols with high selectivity. In 0.5 m KHCO3, such FeP NA/TM is capable of achieving a high Faradaic efficiency (FE
) up to 80.2 %, with a total FE
of 94.3 % at −0.20 V vs. reversible hydrogen electrode. Density functional theory calculations reveal that the FeP(211) surface significantly promotes the adsorption and reduction of CO2 toward CH3OH owing to the synergistic effect of two adjacent Fe atoms, and the potential‐determining step is the hydrogenation process of *CO.
Efficient Electrosynthesis of Syngas with Tunable CO/H2Ratios over ZnxCd1−xS‐Amine Inorganic–Organic Hybrids
Authors: Meng Nannan , Liu Cuibo , Liu Yang , Yu Yifu , Zhang Bin 
Published: October 2019

AbstractEfficient electrochemical reduction of CO2and H2O into industrial syngas with tunable CO/H2ratios, especially integrated with anodic organic synthesis to replace the low‐value oxygen evolution reaction (OER), is highly desirable. Here, integration of controllable partial substitution of zinc (Zn) with amine incorporation into CdS‐amine inorganic‐organic hybrids is used to generate highly efficient electrocatalysts for synthesizing syngas with tunable CO/H2ratios (0–19.7), which are important feedstocks for the Fischer–Tropsch process. Diethylenetriamine could enhance the adsorption and accelerate the activation of CO2to form the key intermediate COOH* for CO formation. Zn substitution promoted the hydrogen evolution reaction (HER), leading to tunable CO/H2ratios. Importantly, syngas and dihydroisoquinoline can be simultaneously synthesized by pairing with anodic semi‐oxidation of tetrahydroisoquinoline in a ZnxCd1−xS‐Amine ∥ Ni2P two‐electrode electrolyzer.
Game‐Based Learning in Virtual Worlds: A Multiuser Online Game for Medical Undergraduate Radiology Education within Second Life
Authors: Lorenzo‐Alvarez Rocio , Rudolphi‐Solero Teodoro , Ruiz‐Gomez Miguel J. , Sendra‐Portero Francisco 
Published: October 2019

Game‐based learning can have a positive impact on medical education, and virtual worlds have great potential for supporting immersive online games. It is necessary to reinforce current medical students' knowledge about radiological anatomy and radiological signs. To meet this need, the objectives of this study were: to design a competition‐based game in the virtual world, Second Life and to analyze the students' perceptions of Second Life and the game, as well as to analyze the medium‐term retention of knowledge and the potential impact on the final grades. Ninety out of 197 (45.6%) third‐year medical students voluntarily participated in an online game based on self‐guided presentations and multiple‐choice tests over six 6‐day stages. Participants and non‐participants were invited to perform an evaluation questionnaire about the experience and a post‐exposure knowledge test. Participants rated the experience with mean scores equal to or higher than 8.1 on a 10‐point scale, highlighting the professor (9.5 ± 1.1; mean ± SD) and the virtual environment (8.9 ± 1.1). Participants had better results in the post‐exposure test than non‐participants (59.0 ± 13.5 versus 45.3 ± 11.5; P < 0.001) and a lower percentage of answers left blank (6.7 ± 8.4 versus 13.1 ± 12.9; P = 0.014). Competitive game‐based learning within Second Life is an effective and well‐accepted means of teaching core radiological anatomy and radiological signs content to medical students. The higher medium‐term outcomes obtained by participants may indicate effective learning with the game. Additionally, valuable positive perceptions about the game, the educational contents, and the potential benefit for their education were discovered among non‐participants.
Phosphine‐Activated Lysine Analogues for Fast Chemical Control of Protein Subcellular Localization and Protein SUMOylation
Authors: Wesalo Joshua S. , Luo Ji , Morihiro Kunihiko , Liu Jihe , Deiters Alexander 
Published: October 2019

AbstractThe Staudinger reduction and its variants have exceptional compatibility with live cells but can be limited by slow kinetics. Herein we report new small‐molecule triggers that turn on proteins through a Staudinger reduction/self‐immolation cascade with substantially improved kinetics and yields. We achieved this through site‐specific incorporation of a new set of azidobenzyloxycarbonyl lysine derivatives in mammalian cells. This approach allowed us to activate proteins by adding a nontoxic, bioorthogonal phosphine trigger. We applied this methodology to control a post‐translational modification (SUMOylation) in live cells, using native modification machinery. This work significantly improves the rate, yield, and tunability of the Staudinger reduction‐based activation, paving the way for its application in other proteins and organisms.
Isolated unilateral absence of the pulmonary artery
Authors: Kanno Kenji , Maehara Takamitsu , Yamamoto Taketsugu , Nemoto Daiji , Kigoshi Hironori , Masuda Munetaka 
Published: October 2019

AbstractIsolated unilateral absence of the pulmonary artery (UAPA) is a rare malformation. It is associated with respiratory symptoms, such as dyspnea or hemoptysis. We suggest that surgical treatment should be positively considered in patients with UAPA who are severely symptomatic and who have no other cardiovascular or respiratory comorbidities.
Selective Deposition of Cobalt and Copper Oxides on BiVO4 Facets for Enhancement of CO2 Photocatalytic Reduction to Hydrocarbons
Authors: Yu Xiang , Ordomsky Vitaly V. , Khodakov Andrei Y. 
Published: October 2019

AbstractThe nanostructure of a semiconductor is a crucial parameter for efficient photocatalytic performance. Hereby, we have synthesized monoclinic bismuth vanadate (BiVO4) crystals with controlled ratio of {010} and {110} facets. The selective deposition of CuOx and CoOx over {010} and {110} facets has been performed using photo‐reduction and photo‐oxidation methods, respectively. It resulted in a highly efficient charge separation of photogenerated electrons and holes and enhancement of the photocatalytic reduction of CO2 by H2O into hydrocarbons, including CH4, C2H6 and C3H8. The controlled co‐catalyst deposition over different semiconductor facets provides a strategy for the synthesis of hydrocarbons from CO2 and H2O by efficient charge separation.
Photoionization Mass Spectrometry for Online Detection of Reactive and Unstable Gas‐Phase Intermediates in Heterogeneous Catalytic Reactions
Authors: You Rui , Huang Weixin 
Published: October 2019

AbstractHeterogeneous catalytic reactions always involve surface intermediates on catalyst surfaces, and some of them also involve reactive and unstable gas‐phase intermediates such as radicals and alkyl hydroperoxides. Online detection of these gas‐phase intermediates is of great importance for fundamentally understanding reaction mechanisms of relevant heterogeneous catalytic reactions, designing structures of efficient catalysts and optimizing reactors. However, it has remained a long‐time challenge due to the lack of routine characterization techniques. Herein we review recent progress on applications of photoionization mass spectrometry in online detection of reactive and unstable gas‐phase intermediates in heterogeneous catalytic reactions. The development and advantages of photoionization mass spectrometry and the relevant equipment setup for heterogeneous catalysis studies are also described. Finally, a future perspective is given.
Enhancement of the Yield of Ammonia by Hydrogen‐Sink Effect during Plasma Catalysis
Authors: Shah Javishk , Gorky Fnu , Psarras Peter , Seong Bomsaerah , Gómez‐Gualdrón Diego A. , Carreon Maria L. 
Published: October 2019

AbstractPlasma‐catalytic ammonia synthesis has been known since the early 1900s, but only until now efforts to optimize catalysts for this purpose are emerging. Here, we investigate various transition metals, low‐melting‐point metals, and gallium‐rich alloy catalysts for their activity towards ammonia production under a plasma environment. The best three pure metal catalysts were Ni, Sn and Au, which are not traditional catalysts for the current industrial ammonia synthesis. The ammonia yields for these catalysts were 34 %, 29 %, and 19 %, respectively. Synergistic effects were detected when employing alloys, as some alloys presented ∼25–50 % higher yields than their constituent metals. The employed metals were classified into two categories. Category I metals (Cu, Ag, Au and Fe), which are nitrophobic (excluding Fe, the Haber‐Bosch catalyst) and poor hydrogen sinks. For these metals, the measured concentration of Hα in the gas phase tended to correlate inversely with ammonia yield and directly with the H binding strength on the catalyst surface. Category II metals (Ga, In, Sn and Ni), which are good hydrogen sinks, tend to have a lower concentration of Hα in the gas phase than that of category I metals, which is consistent with their expected sink behavior. For these metals, the concentration of Hα correlates with ammonia yield. Plasma characterization experiments and DFT calculations suggest that the higher performance of Ni and Sn is related to the benefit of dissolving hydrogen to slow down H recombination, which is a feature that could be potentially optimized in future studies by rationally altering the catalyst composition.
Ruthenium(II)‐Catalyzed Hydrogen Isotope Exchange of Pharmaceutical Drugs by C−H Deuteration and C−H Tritiation
Authors: Müller Valentin , Weck Remo , Derdau Volker , Ackermann Lutz 
Published: October 2019

AbstractWell‐defined ruthenium(II) biscarboxylate complexes enabled selective ortho‐deuteration with weakly‐coordinating, synthetically useful carboxylic acid with outstanding levels of isotopic labeling. The robust nature of the catalytic system was reflected by a broad functional group tolerance in an operationally‐simple manner, allowing the isotope labeling of challenging pharmaceuticals and bioactive heterocyclic motifs. The synthetic power of our method was highlighted by the selective tritium‐labeling of repaglinide, an antidiabetic drug, providing access to defined tritium labeled therapeutics.
Fabrication of Core‐Shell Ni2P@N, P−Co‐Doped Carbon/Reduced Graphene Oxide Composite as Anode Material for Lithium‐ and Sodium‐Ion Batteries
Authors: Li Yongsheng , Zhang Jianmin , Li Dan , Ding Jie , Liu Yushan , Cai Qiang 
Published: October 2019

AbstractCommonly, carbon layer was a suitable choice to enhance the conductivity and reduce the large volume effect of Ni2P nanoparticles (NPs) in electrochemical applications. The doped nitrogen (N) and phosphorous (P) atoms in carbon could further improve its performance. In this paper, core‐shell structure Ni2P@N, P‐co‐doped carbon (Ni2P@N, P−C) NPs were loaded onto reduced graphene oxide nanosheets (GN) to form new composite serial Ni2P@N, P−C/GN, which was designed for the combination of these merits and successfully obtained by two‐step method (firstly hydrothermal process and secondly phosphorization process). As anodes for LIBs and SIBs, the responding electrochemical studies showed the Ni2P@N, P−C/GN‐0.4 electrode exhibited an outstanding specific capacity of 450 mA h g−1 at 5 A g−1 after 2000 cycles in lithium‐ion batteries (LIBs) and maintained 110 mA h g−1 at 2 A g−1 after 3000 cycles in sodium‐ion batteries (SIBs), respectively. These results showed that Ni2P@N, P−C/GN material could be an excellent candidate for energy storage area.
Challenges for the Periodic Systems of Elements: Chemical, Historical and Mathematical Perspectives
Authors: Restrepo Guillermo 
Published: October 2019

AbstractWe celebrate 150 years of periodic systems that reached their maturity in the 1860s. They began as pedagogical efforts to project corpuses of substances on the similarity and order relationships of the chemical elements. However, these elements are not the canned substances wrongly displayed in many periodic tables, but rather the abstract preserved entities in compound transformations. We celebrate the systems, rather than their tables or ultimate table. The periodic law, we argue, is not an all‐encompassing achievement, as it does not apply to every property of all elements and compounds. Periodic systems have been generalised as ordered hypergraphs, which solves the long‐lasting question on the mathematical structure of the systems. In this essay, it is shown that these hypergraphs may solve current issues such as order reversals in super‐heavy elements and lack of system predictive power. We discuss research in extending the limits of the systems in the super‐heavy‐atom region and draw attention to other limits: the antimatter region and the limit arising from compounds under extreme conditions. As systems depend on the known chemical substances (chemical space) and such a space grows exponentially, we wonder whether systems still aim at projecting knowledge of compounds on the relationships among the elements. We claim that systems are not based on compounds anymore, rather on 20th century projections of the 1860s systems of elements on systems of atoms. These projections bring about oversimplifications based on entities far from being related to compounds. A linked oversimplification is the myth of vertical group similarity, which raises questions on the approaches to locate new elements in the system. Finally, we propose bringing back chemistry to the systems by exploring similarity and order relationships of elements using the current information of the chemical space. We ponder whether 19th century periodic systems are still there or whether they have faded away, leaving us with an empty 150thcelebration.
Photoracemization‐Based Viedma Ripening of a BINOL Derivative
Authors: Belletti Giuseppe , Tortora Carola , Mellema Indradevi D. , Tinnemans Paul , Meekes Hugo , Rutjes Floris P. J. T. , Tsogoeva Svetlana B. , Vlieg Elias 
Published: October 2019

AbstractViedma ripening is a deracemization process that has been used to deracemize a range of chiral molecules. The method has two major requirements: the compound needs to crystallize as a conglomerate and it needs to be racemizable under the crystallization conditions. Although conglomerate formation can be induced in different ways, the number of racemization methods is still rather limited. To extend the scope of Viedma ripening, in the present research we applied UV‐light‐induced racemization in a Viedma ripening process, and report the successful deracemization of a BINOL derivative crystallizing as a conglomerate. Irradiation by UV light activates the target compound in combination with an organic base, required to promote the excited‐state proton transfer (ESPT), leading thereafter to racemization. This offers a new tool towards the development of Viedma ripening processes, by using a cheap and “green” catalytic source like UV light to racemize suitable chiral compounds.
Biomimetic Mineralization of Protein Nanogels for Enzyme Protection
Authors: Yu Qianyu , Ma Xiaoteng , Liu Yingze , Zhao Hanying 
Published: October 2019

AbstractProtein nanogels have found a wide variety of applications, ranging from biocatalysis to drug/protein delivery. However, in practical applications, proteins in nanogels may suffer from enzymic hydrolysis and denaturation. Inspired by the structure and functionalities of the fowl eggshells, biomimetic mineralization of protein nanogels was studied in this research. Protein nanogels with embedded porcine pancreas lipase (PPL) in the cross‐linked nanostructures were synthesized through the thiol–disulfide reaction between thiol‐functionalized PPL and poly(N‐isopropylacrylamide) with pendant pyridyl disulfide groups. The nanogels were further reacted with reduced bovine serum albumin (BSA) and BSA molecules were coated on the nanogels. Mineralization of BSA leads to the synthesis of biomineralized shells on the nanogels. With the growth of CaCO3 on the shells, the nanogels aggregate into suprastructures. Thermogravimetric analysis, XRD, dynamic light scattering, and TEM were employed to study the mechanism of the biomineralization process and analyze the structures of the mineralized nanogels. The biomineralized shells can effectively protect the PPL molecules from hydrolysis by trypsin; meanwhile, the nanosized channels on the mineralized shells allow the transport of small‐molecule substrates across the shells. Bioactivity measurements indicate that PPL in the nanogels maintains more than 80 % bioactivity after biomineralization.
Toward Transition‐Metal‐Templated Construction of Arylated B4 Chains by Dihydroborane Dehydrocoupling
Authors: Lenczyk Carsten , Roy Dipak Kumar , Oberdorf Kai , Nitsch Jörn , Dewhurst Rian D. , Radacki Krzysztof , Halet Jean‐François , Marder Todd B. , Bickelhaupt Matthias , Braunschweig Holger 
Published: October 2019

AbstractThe reactivity of a diruthenium tetrahydride complex towards three selected dihydroboranes was investigated. The use of [DurBH2] (Dur=2,3,5,6‐Me4C6H) and [(Me3Si)2NBH2] led to the formation of bridging borylene complexes of the form [(Cp*RuH)2BR] (Cp*=C5Me5; 1 a: R=Dur; 1 b: R=N(SiMe3)2) through oxidative addition of the B−H bonds with concomitant hydrogen liberation. Employing the more electron‐deficient dihydroborane [3,5‐(CF3)2‐C6H3BH2] led to the formation of an anionic complex bearing a tetraarylated chain of four boron atoms, namely Li(THF)4[(Cp*Ru)2B4H5(3,5‐(CF3)2C6H3)4] (4), through an unusual, incomplete threefold dehydrocoupling process. A comparative theoretical investigation of the bonding in a simplified model of 4 and the analogous complex nido‐[1,2(Cp*Ru)2(μ‐H)B4H9] (I) indicates that there appear to be no classical σ‐bonds between the boron atoms in complex I, whereas in the case of 4 the B4 chain better resembles a network of three B−B σ bonds, the central bond being significantly weaker than the other two.