bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable Silicene in Graphene/Silicene Van der Waals Heterostructures
Authors: Li Geng , Zhang Lizhi , Xu Wenyan , Pan Jinbo , Song Shiru , Zhang Yi , Zhou Haitao , Wang Yeliang , Bao Lihong , Zhang Yu‐Yang , Du Shixuan , Ouyang Min , Pantelides Sokrates T. , Gao Hong‐Jun 
Published: October 2018

AbstractSilicene‐based van der Waals heterostructures are theoretically predicted to have interesting physical properties, but their experimental fabrication has remained a challenge because of the easy oxidation of silicene in air. Here, the fabrication of graphene/silicene van der Waals heterostructures by silicon intercalation is reported. Density functional theory calculations show weak interactions between graphene and silicene layers, confirming the formation of van der Waals heterostructures. The heterostructures show no observable damage after air exposure for extended periods, indicating good air stability. The I–V characteristics of the vertical graphene/silicene/Ru heterostructures show rectification behavior.
Understanding Detrimental and Beneficial Grain Boundary Effects in Halide Perovskites
Authors: Adhyaksa Gede W. P. , Brittman Sarah , Āboliņš Haralds , Lof Andries , Li Xueying , Keelor Joel D. , Luo Yanqi , Duevski Teodor , Heeren Ron M. A. , Ellis Shane R. , Fenning David P. , Garnett Erik C. 
Published: October 2018

AbstractGrain boundaries play a key role in the performance of thin‐film optoelectronic devices and yet their effect in halide perovskite materials is still not understood. The biggest factor limiting progress is the inability to identify grain boundaries. Noncrystallographic techniques can misidentify grain boundaries, leading to conflicting literature reports about their influence; however, the gold standard – electron backscatter diffraction (EBSD) – destroys halide perovskite thin films. Here, this problem is solved by using a solid‐state EBSD detector with 6000 times higher sensitivity than the traditional phosphor screen and camera. Correlating true grain size with photoluminescence lifetime, carrier diffusion length, and mobility shows that grain boundaries are not benign but have a recombination velocity of 1670 cm s−1, comparable to that of crystalline silicon. Amorphous grain boundaries are also observed that give rise to locally brighter photoluminescence intensity and longer lifetimes. This anomalous grain boundary character offers a possible explanation for the mysteriously long lifetime and record efficiency achieved in small grain halide perovskite thin films. It also suggests a new approach for passivating grain boundaries, independent of surface passivation, to lead to even better performance in optoelectronic devices.
Solution‐Processed Ion‐Free Organic Ratchets with Asymmetric Contacts
Authors: Huang Jianfei , Karki Akchheta , Brus Viktor V. , Hu Yuanyuan , Phan Hung , Lill Alexander T. , Wang Ming , Bazan Guillermo C. , Nguyen Thuc‐Quyen 
Published: October 2018

AbstractIon‐free organic ratchets with asymmetric injecting contacts (AICs) are fabricated using solution‐processable organic semiconductors. Scanning Kelvin probe microscopy analysis reveals that the rectifying function is achieved via the “charge pump” mechanism. Electrical characterizations show that the device can readily operate under industrial standard radio frequency and its high‐frequency performance may be enhanced through further material/device engineering. The built‐in asymmetric feature exempts the devices from the complicated material design, device processing, and performance decay associated with the use of ion/semiconductor blends in ionic‐organic ratchets. Thus, the AIC ratchets can deliver a persisting ratchet effect and have excellent material compatibility toward organic semiconductors.
Heterostructures Based on 2D Materials: A Versatile Platform for Efficient Catalysis
Authors: Shifa Tofik Ahmed , Wang Fengmei , Liu Yang , He Jun 
Published: October 2018

AbstractThe unique structural and electronic properties of 2D materials, including the metal and metal‐free ones, have prompted intense exploration in the search for new catalysts. The construction of different heterostructures based on 2D materials offers great opportunities for boosting the catalytic activity in electo(photo)chemical reactions. Particularly, the merits resulting from the synergism of the constituent components and the fascinating properties at the interface are tremendously interesting. This scenario has now become the state‐of‐the‐art point in the development of active catalysts for assisting energy conversion reactions including water splitting and CO2 reduction. Here, starting from the theoretical background of the fundamental concepts, the progressive developments in the design and applications of heterostructures based on 2D materials are traced. Furthermore, a personal perspective on the exploration of 2D heterostructures for further potential application in catalysis is offered.
Antibacterial Carbon‐Based Nanomaterials
Authors: Xin Qi , Shah Hameed , Nawaz Asmat , Xie Wenjing , Akram Muhammad Zain , Batool Aisha , Tian Liangqiu , Jan Saad Ullah , Boddula Rajender , Guo Beidou , Liu Qian , Gong Jian Ru 
Published: October 2018

AbstractThe emergence and global spread of bacterial resistance to currently available antibiotics underscore the urgent need for new alternative antibacterial agents. Recent studies on the application of nanomaterials as antibacterial agents have demonstrated their great potential for management of infectious diseases. Among these antibacterial nanomaterials, carbon‐based nanomaterials (CNMs) have attracted much attention due to their unique physicochemical properties and relatively higher biosafety. Here, a comprehensive review of the recent research progress on antibacterial CNMs is provided, starting with a brief description of the different kinds of CNMs with respect to their physicochemical characteristics. Then, a detailed introduction to the various mechanisms underlying antibacterial activity in these materials is given, including physical/mechanical damage, oxidative stress, photothermal/photocatalytic effect, lipid extraction, inhibition of bacterial metabolism, isolation by wrapping, and the synergistic effect when CNMs are used in combination with other antibacterial materials, followed by a summary of the influence of the physicochemical properties of CNMs on their antibacterial activity. Finally, the current challenges and an outlook for the development of more effective and safer antibacterial CNMs are discussed.
Achieving Balanced Crystallinity of Donor and Acceptor by Combining Blade‐Coating and Ternary Strategies in Organic Solar Cells
Authors: Zhang Lin , Xu Xianbin , Lin Baojun , Zhao Heng , Li Tengfei , Xin Jingming , Bi Zhaozhao , Qiu Guanxian , Guo Shengwei , Zhou Ke , Zhan Xiaowei , Ma Wei 
Published: October 2018

AbstractAs a prototype tool for slot‐die coating, blade‐coating exhibits excellent compatibility with large‐area roll‐to‐roll coating. A ternary organic solar cell based on PBDB‐T:PTB7‐Th:FOIC blends is fabricated by blade‐coating and exhibits a power conversion efficiency of 12.02%, which is one of the highest values for the printed organic solar cells in ambient environment. It is demonstrated that blade‐coating can enhance crystallization of these three materials, but the degree of induction is different (FOIC > PBDB‐T > PTB7‐Th). Thus, the blade‐coated PBDB‐T:FOIC device presents much higher electron mobility than hole mobility due to the very high crystallinity of FOIC. Upon the addition of PTB7‐Th into the blade‐coated PBDB‐T:FOIC blends, the crystallinity of FOIC decreases together with the corresponding electron mobility, due to the better miscibility between PTB7‐Th and FOIC. The ternary strategy not only maintains the well‐matched crystallinity and mobilities, but also increases the photocurrent with complementary light absorption as well as the Förster resonant energy transfer. Furthermore, small domains with homogeneously distributed nanofibers are observed in favor of the exciton dissociation and charge transport. This combination of blade‐coating and ternary strategies exhibits excellent synergistic effect in optimizing morphology, showing great potential in the large‐area fabrication of highly efficient organic solar cells.
Tailor‐Made Microporous Metal–Organic Frameworks for the Full Separation of Propane from Propylene Through Selective Size Exclusion
Authors: Wang Hao , Dong Xinglong , Colombo Valentina , Wang Qining , Liu Yanyao , Liu Wei , Wang Xin‐Long , Huang Xiao‐Ying , Proserpio Davide M. , Sironi Angelo , Han Yu , Li Jing 
Published: October 2018

AbstractAdsorptive separation of olefin/paraffin mixtures by porous solids can greatly reduce the energy consumption associated with the currently employed cryogenic distillation technique. Here, the complete separation of propane and propylene by a designer microporous metal–organic framework material is reported. The compound, Y6(OH)8(abtc)3(H2O)6(DMA)2 (Y‐abtc, abtc = 3,3′,5,5′‐azobenzene‐tetracarboxylates; DMA = dimethylammonium), is rationally designed through topology‐guided replacement of inorganic building units. Y‐abtc is both thermally and hydrothermally robust, and possesses optimal pore window size for propane/propylene separation. It adsorbs propylene with fast kinetics under ambient temperature and pressure, but fully excludes propane, as a result of selective size exclusion. Multicomponent column breakthrough experiments confirm that polymer‐grade propylene (99.5%) can be obtained by this process, demonstrating its true potential as an alternative sorbent for efficient separation of propane/propylene mixtures.
Revealing the Interplay of Structural Phase Transitions and Ferroelectric Switching in Mixed Phase BiFeO3
Authors: Naden Aaron B. , Edwards David , Neumayer Sabine M. , Guy Joseph G. M. , Rodriguez Brian J. , Bassiri‐Gharb Nazanin , Kumar Amit 
Published: October 2018

AbstractEpitaxially strained BiFeO3 thin films with coexisting tetragonal‐ and rhombohedral‐like phases exhibit a range of intriguing functional properties, often strongly related to the unique microstructure of the film. Here enhancements in electromechanical response are reported during simultaneous nanoscale application of electric field and localized stress. These enhancements manifest in the form of peaks, or humps, in the piezoresponse hysteresis loops obtained under a select polarity of applied electric field, corresponding nominally to a downward polarization. Using a variation of band excitation piezoresponse force spectroscopy to collect electromechanical hysteresis loops and to simultaneously monitor the elastic behavior during switching, a comprehensive picture of the complex interplay of ferroelastic structural transitions and ferroelectric switching and its impact on the overall functional response are developed. Such an understanding is a crucial step toward realizing practical electronic devices, such as pressure sensors, incorporating this promising material.
Clustering and Self‐Recovery of Slanted Hydrogel Micropillars
Authors: Lee Hyemin , Kim Jun‐Hyun , Wu Gaoxiang , Lee Hae‐Min , Kim Jaekyoung , Kwon Dokyeong , Yang Shu , Kim Chang‐Koo , Yoon Hyunsik 
Published: October 2018

AbstractSlanted high‐aspect‐ratio polymer pillars are studied for their unique properties such as unidirectional spreading of liquid, directional adhesions, or alignment of cells, where the pillars are in constant contact with water or in a humid environment. These pillars, however, tend to cluster upon water evaporation due to the capillary force and lowered modulus of the pillars. Here, spontaneous recovery of clustered slanted hydrogel pillars to their original shape is presented by exploiting the modulus change of hydrogel materials during water evaporation. The clustering and recovery of the slanted hydrogel micropillars are monitored in situ by optical microscopy and environmental scanning electron microscopy. To elucidate sequential clustering and recovery mechanism, the adhesion force between the pillars and the restoring force is compared. Finally, the dynamic change of optical transparency is exploited as the result of switching between clustering and recovery of the slanted micropillars for display. The study of the deformation and recovery of slanted hydrogel pillars will offer insights into geometrical and material designs in water‐based applications.
High Selectivity Gas Separation by Interfacial Diffusion Membranes
Authors: Wang David K. , Bauer Ralph A. , Yan Kelan , Mergos Ioannis A. , Yang Zi , Zhou Yi , Verweij Hendrik 
Published: October 2018

AbstractA new generation of inorganic/organic polymeric interfacial diffusion membranes is presented that have unprecedented combinations of high selectivity and flux. The membranes consist of an inorganic scaffold, with pores that are filled with a thermoplastic polymer that crystallizes in the pore space while a nm thin interfacial area remains amorphous. The polyetherimide, present on top of the α‐Al2O3 scaffold as a 3.9 µm amorphous layer, and inside the near‐surface area of the scaffold over ≈130 nm, is partly crystallized. Combinations of extremely high gas selectivities are found of >2200 for CO2/N2 and >4000 for H2/N2, combined with CO2 and H2 permeances of 2.2 × 10−10 and 4.0 × 10−10 [mol (m2 Pa s)−1], respectively. For CO2 (5–50%) and N2 dry and water‐saturated gas mixtures, only CO2 permeance is detected. The presence of water appears to affect CO2 permeances very little at both 22 and 57 °C. Selective molecular transport is blocked in the crystalline areas and takes place exclusively in the amorphous interfacial area. It is governed by a combination of affinity, mobility, and size‐exclusion. Conservative estimates of the membrane permeability indicate that their properties by far exceed the Robeson boundary.
Curvature Elasticity‐Driven Leaflet Asymmetry and Interleaflet Raft Coupling in Supported Membranes
Authors: Ryu Yong‐Sang , Jordan Luke R. , Wittenberg Nathan J. , Kim Sang Moon , Yoo Daehan , Jeong Cherlhyun , Warrington Arthur E. , Rodriguez Moses , Oh Sang‐Hyun , Lee Sin‐Doo 
Published: October 2018

AbstractMembrane curvature is closely associated with spatial distribution of lipids and curvature can influence the formation of lipid rafts in biological membranes. However, it is still unclear how the curvature elasticity plays a role on the asymmetric distribution of lipids across the membrane leaflets, especially, during the process of the raft domain growth. Using supported lipid membranes on wedge‐shaped substrates with alternating positive and negative curvatures, curvature‐mediated asymmetry of lipid raft domains is observed across the membrane leaflets accompanied by glycolipid receptor (GM1 and GT1b) localization. The raft domains initially appear only in a membrane leaflet possessing negative curvatures. In the presence of the interleaflet coupling, they evolve to generate the transverse registry across the membrane bilayer. It is shown that a human recombinant antibody rHIgM12 is co‐localized with the rafts formed at the peaks and valleys of the wedge substrate, indicating that the spatial distribution of its receptor (GT1b) is indeed manifested by the site‐specific formation of asymmetric raft domains through the curvature elasticity. The platform can be used to explore the mechanism for the leaflet asymmetry and lipid sorting in terms of the membrane curvature, the composition, and the receptor presentation.
High Energy Density CNT/NaI Composite Cathodes for Sodium‐Ion Batteries
Authors: Kim Sanghyeon , Li Xiangming , Sang Lingzi , Yun Young Soo , Nuzzo Ralph G. , Gewirth Andrew A. , Braun Paul V. 
Published: October 2018

AbstractThe Na‐iodine system has potential as a positive electrode in sodium‐ion batteries due to its fast reaction kinetics and high energy density. Here, the fabrication of a NaI‐loaded carbon nanotube (CNT) mat cathode is presented and the use of NaI as a Na‐ion battery cathode is reported for the first time. Freestanding electrodes show a capacity retention of 92% after 100 cycles at 100 mA h g−1 and a high specific energy density (≈473 W h kg−1, second discharge basis vs Na metal) and small hysteresis (0.03 V). Adding a CNT mat interlayer between the NaI composite cathode and the separator, and fluoroethylene carbonate to the electrolyte significantly suppresses shuttling of active materials during cycling. Using ex situ X‐ray photoelectron spectroscopy and Raman data, an understanding of the relevant processes occurring during cycling of the CNT/NaI cathode is developed.
Toward Fully Manufacturable, Fiber Assembly–Based Concurrent Multimodal and Multifunctional Sensors for e‐Textiles
Authors: Kapoor Ashish , McKnight Michael , Chatterjee Kony , Agcayazi Talha , Kausche Hannah , Bozkurt Alper , Ghosh Tushar K. 
Published: October 2018

AbstractSoft polymer‐based sensors as an integral part of textile structures have attracted considerable scientific and commercial interest recently because of their potential use in healthcare, security systems, and other areas. While electronic sensing functionalities can be incorporated into textiles at one or more of the hierarchical levels of molecules, fibers, yarns, or fabrics, arguably a more practical and inconspicuous means to introduce the desired electrical characteristics is at the fiber level, using processes that are compatible to textiles. Here, a prototype multimodal and multifunctional sensor array formed within a woven fabric structure using bicomponent fibers with ordered insulating and conducting segments is reported. The multifunctional characteristics of the sensors are successfully demonstrated by measuring tactile, tensile, and shear deformations, as well as wetness and biopotential. While the unobtrusive integration of sensing capabilities offers possibilities to preserve all desirable textile qualities, this scaled‐up fiber‐based approach demonstrates the potential for scalable and facile manufacturability of practical e‐textile products using low‐cost roll‐to‐roll processing of large‐area flexible sensor systems and can be remarkably effective in advancing the field of e‐textiles.
Functional Liquid Metal Nanoparticles Produced by Liquid‐Based Nebulization
Authors: Tang Shi‐Yang , Qiao Ruirui , Lin Yiliang , Li Yuhuan , Zhao Qianbin , Yuan Dan , Yun Guolin , Guo Jinhong , Dickey Michael D. , Huang Tony Jun , Davis Thomas P. , Kalantar‐Zadeh Kourosh , Li Weihua 
Published: October 2018

AbstractFunctional liquid metal nanoparticles (NPs), produced from eutectic alloys of gallium, promise new horizons in the fields of sensors, microfluidics, flexible electronics, catalysis, and biomedicine. Here, the development of a vapor cavity generating ultrasonic platform for nebulizing liquid metal within aqueous media for the one‐step production of stable and functional liquid metal NPs is shown. The size distribution of the NPs is fully characterized and it is demonstrated that various macro and small molecules can also be grafted onto these liquid metal NPs during the liquid‐based nebulization process. The cytotoxicity of the NPs grafted with different molecules is further explored. Moreover, it is shown that it is possible to control the thickness of the oxide layer on the produced NPs using electrochemistry that can be embedded within the platform. It is envisaged that this platform can be adapted as a cost‐effective and versatile device for the rapid production of functional liquid metal NPs for future liquid metal‐based optical, electronic, catalytic, and biomedical applications.
1D/2D TiO2/MoS2 Hybrid Nanostructures for Enhanced Photocatalytic CO2 Reduction
Authors: Xu Feiyan , Zhu Bicheng , Cheng Bei , Yu Jiaguo , Xu Jingsan 
Published: October 2018

AbstractPhotocatalytic reduction of CO2 into solar fuels is recognized an attractive approach to solve the environmental and energy crisis. MoS2, a type of 2D transition metal dichalcogenides, has attracted significant attention in photoelectronics, sensors and photo/electrocatalytic water splitting owing to its remarkable properties. Nevertheless, to date, MoS2 is barely used as (co)catalyst for CO2 photoreduction. Herein, novel 1D/2D TiO2/MoS2 nanostructured hybrid with TiO2 fibers covered by MoS2 nanosheets by hydrothermal transformation method is fabricated. The MoS2 sheet arrays show a lateral size of ≈80 nm and a thickness of down to 2 nm, vertically and uniformly standing upon the TiO2 fibers. X‐ray photoelectron spectroscopy (XPS) results and density functional theory (DFT) calculation imply the intimate chemical interaction between MoS2 and TiO2 upon hybridization, which can facilitate electron–hole separation upon photoexcitation. In addition, the hierarchical TiO2/MoS2 nanostructure shows enhanced optical absorption and CO2 adsorption, therefore, a superior photocatalytic activity for reducing CO2 into methane and methanol is achieved over the hybrid as compared to pristine TiO2. Isotope (13C) tracer test confirms that the products are produced from the photocatalytic reduction of the CO2 source instead of any organic contaminants. This work offers an alternative approach to rationally design and synthesize TiO2‐based photocatalysts toward high‐efficiency photoreduction of CO2.
Broadband Metamaterial Absorbers
Authors: Yu Peng , Besteiro Lucas V. , Huang Yongjun , Wu Jiang , Fu Lan , Tan Hark H. , Jagadish Chennupati , Wiederrecht Gary P. , Govorov Alexander O. , Wang Zhiming 
Published: October 2018

AbstractThe recent rise of metamaterials opens new opportunities for absorbers due to their designed electrodynamic properties and effects, allowing the creation of materials with effective values of permittivity and permeability that are not available in naturally occurring materials. Since their first experimental demonstration in 2008, recent literature has offered great advances in metamaterial perfect absorbers (MMPAs) operating at frequencies from radio to optical. Broadband absorbers are indispensable in thermophotovoltaics, photodetection, bolometry, and manipulation of mechanical resonances. Although it is easy to obtain MMPAs with single band or multiband, achieving broadband MMPA (BMMPA) remains a challenge due to the intrinsically narrow bandwidth of surface plasmon polaritons, localized surface plasmon resonances generated on metallic surfaces at nanoscale or high Q‐factor in GHz region. To guide future development of BMMPA, recent progress is reviewed here: the methods to create broadband absorption and their potential applications. The four mainstream methods to achieve BMMPAs are introduced, including planar and vertical element arrangements, their welding with lumped elements and the use of plasmonic nanocomposites, accompanied by the description of other, less common approaches. Following this, applications of BMMPA in solar photovoltaics, photodetection, bolometry, and manipulation of mechanical resonances are reviewed. Finally, challenges and prospects are discussed.