bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enrichment of Precious Metals from Wastewater with Core–Shell Nanoparticles of Iron
Authors: Ling Lan , Huang Xiao‐Yue , Zhang Wei‐Xian 
Published: March 2018

AbstractLarge‐scale deployment of zero‐valent iron nanoparticles for enrichment and recovery of gold from industrial wastewater is reported. Iron nanoparticles have a core–shell structure in which a metallic iron core is enclosed with a thin layer of iron oxides/hydroxides. The two nanocomponents offer synergistic functions for rapid separation, enrichment, and stabilization of metal ions such as Au, Ag, Ni, and Cu. Thanks to the advantages of small size, large surface area, and high reactivity, only a small amount of iron nanoparticles are needed. The recovered nanoparticles thus contain precious metals well above conventional metal ores (e.g., >100 g Au ton−1). Cost‐effective recovery of precious metals from trace‐level sources such as wastewater looks promising.
Intercalated Water and Organic Molecules for Electrode Materials of Rechargeable Batteries
Authors: Lee Hyeon Jeong , Shin Jaeho , Choi Jang Wook 
Published: March 2018

AbstractThe intrinsic limitations of lithium‐ion batteries (LIBs) with regard to safety, cost, and the availability of raw materials have promoted research on so‐called “post‐LIBs”. The recent intense research of post‐LIBs provides an invaluable lesson that existing electrode materials used in LIBs may not perform as well in post‐LIBs, calling for new material designs compliant with emerging batteries based on new chemistries. One promising approach in this direction is the development of materials with intercalated water or organic molecules, as these materials demonstrate superior electrochemical performance in emerging battery systems. The enlarged ionic channel dimensions and effective shielding of the electrostatic interaction between carrier ions and the lattice host are the origins of the observed electrochemical performance. Moreover, these intercalants serve as interlayer pillars to sustain the framework for prolonged cycles. Representative examples of such intercalated materials applied to batteries based on Li+, Na+, Mg2+, and Zn2+ ions and supercapacitors are considered, along with their impact in materials research.
Self‐Powered Wearable Electronics Based on Moisture Enabled Electricity Generation
Authors: Shen Daozhi , Xiao Ming , Zou Guisheng , Liu Lei , Duley Walter W. , Zhou Y. Norman 
Published: March 2018

AbstractMost state‐of‐the‐art electronic wearable sensors are powered by batteries that require regular charging and eventual replacement, which would cause environmental issues and complex management problems. Here, a device concept is reported that can break this paradigm in ambient moisture monitoring—a new class of simple sensors themselves can generate moisture‐dependent voltage that can be used to determine the ambient humidity level directly. It is demonstrated that a moisture‐driven electrical generator, based on the diffusive flow of water in titanium dioxide (TiO2) nanowire networks, can yield an output power density of up to 4 µW cm−2 when exposed to a highly moist environment. This performance is two orders of magnitude better than that reported for carbon‐black generators. The output voltage is strongly dependent on humidity of ambient environment. As a big breakthrough, this new type of device is successfully used as self‐powered wearable human‐breathing monitors and touch pads, which is not achievable by any existing moisture‐induced‐electricity technology. The availability of high‐output self‐powered electrical generators will facilitate the design and application of a wide range of new innovative flexible electronic devices.
Revealing the Contribution of Individual Factors to Hydrogen Evolution Reaction Catalytic Activity
Authors: Zhou Yu , Silva Jose Luis , Woods John M. , Pondick Joshua V. , Feng Qingliang , Liang Zhixiu , Liu Wen , Lin Li , Deng Bingchen , Brena Barbara , Xia Fengnian , Peng Hailin , Liu Zhongfan , Wang Hailiang , Araujo Carlos Moyses , Cha Judy J. 
Published: March 2018

AbstractFor the electrochemical hydrogen evolution reaction (HER), the electrical properties of catalysts can play an important role in influencing the overall catalytic activity. This is particularly important for semiconducting HER catalysts such as MoS2, which has been extensively studied over the last decade. Herein, on‐chip microreactors on two model catalysts, semiconducting MoS2 and semimetallic WTe2, are employed to extract the effects of individual factors and study their relations with the HER catalytic activity. It is shown that electron injection at the catalyst/current collector interface and intralayer and interlayer charge transport within the catalyst can be more important than thermodynamic energy considerations. For WTe2, the site‐dependent activities and the relations of the pure thermodynamics to the overall activity are measured and established, as the microreactors allow precise measurements of the type and area of the catalytic sites. The approach presents opportunities to study electrochemical reactions systematically to help establish rational design principles for future electrocatalysts.
A Universal Strategy for Intimately Coupled Carbon Nanosheets/MoM Nanocrystals (M = P, S, C, and O) Hierarchical Hollow Nanospheres for Hydrogen Evolution Catalysis and Sodium‐Ion Storage
Authors: Yang Yong , Luo Mingchuan , Xing Yi , Wang Shitong , Zhang Weiyu , Lv Fan , Li Yingjie , Zhang Yelong , Wang Wei , Guo Shaojun 
Published: March 2018

AbstractIntimately coupled carbon/transition‐metal‐based hierarchical nanostructures are one of most interesting electrode materials for boosting energy conversion and storage applications owing to the strong synergistic effect between the two components and appealing structural stability. Herein, a universal method is reported for making hierarchical hollow carbon nanospheres (HCSs) with intimately coupled ultrathin carbon nanosheets and Mo‐based nanocrystals. The in situ and confined reaction of the synthetic strategy can not only allow the aggregation of the nanocrystals to be impeded, but also endows extremely intimate coupled interaction between the conductive carbon nanosheets and the nanocrystals MoM (M = P, S, C and O). As a proof of concept, the as‐prepared MoP/C HCSs exhibit extraordinary hydrogen evolution reaction electrocatalytic activity with small overpotential and robust durability in both acidic and alkaline solutions. In addition, the unique sheet‐on‐sheet MoS2/C HCSs as an anode demonstrate high capacity, great rate capabilities, and long‐term cycles for sodium‐ion batteries (SIBs). The capacity can be maintained at 410 mA h g−1 even after 1000 cycles even at a high current density of 4 A g−1, one of the best reported values for MoS2‐based electrode materials for SIBs. The present work highlights the importance of designing and fabricating functional strongly coupled hybrid materials for enhancing energy conversion and storage applications.
A Supercompressible, Elastic, and Bendable Carbon Aerogel with Ultrasensitive Detection Limits for Compression Strain, Pressure, and Bending Angle
Authors: Zhuo Hao , Hu Yijie , Tong Xing , Chen Zehong , Zhong Linxin , Lai Haihong , Liu Linxiang , Jing Shuangshuang , Liu Qingzhong , Liu Chuanfu , Peng Xinwen , Sun Runcang 
Published: March 2018

AbstractUltralight and compressible carbon materials have promising applications in strain and pressure detection. However, it is still difficult to prepare carbon materials with supercompressibility, elasticity, stable strain–electrical signal response, and ultrasensitive detection limits, due to the challenge in structural regulation. Herein, a new strategy to prepare a reduced graphene oxide (rGO)‐based lamellar carbon aerogels with unexpected and integrated performances by designing wave‐shape rGO layers and enhancing the interaction among the rGO layers is demonstrated. Addition of cellulose nanocrystalline and low‐molecular‐weight carbon precursors enhances the interaction among rGO layers and thus produces an ultralight, flexible, and superstable structure. The as‐prepared carbon aerogel displays a supercompressibility (undergoing an extreme strain of 99%) and elasticity (100% height retention after 10 000 cycles at a strain of 30%), as well as stable strain–current response (at least 10 000 cycles). Particularly, the carbon aerogel is ultrasensitive for detecting tiny change in strain (0.012%) and pressure (0.25 Pa), which are the lowest detection limits for compressible carbon materials reported in the literature. Moreover, the carbon aerogel exhibits excellent bendable performance and can detect an ultralow bending angle of 0.052°. Additionally, the carbon aerogel also demonstrates its promising application as wearable devices.
Implantable Synthetic Immune Niche for Spatiotemporal Modulation of Tumor‐Derived Immunosuppression and Systemic Antitumor Immunity: Postoperative Immunotherapy
Authors: Phuengkham Hathaichanok , Song Chanyoung , Um Soong Ho , Lim Yong Taik 
Published: March 2018

AbstractThe development of biomaterial‐based immune niches that can modulate immunosuppressive factors in tumor microenvironment (TME) will be a key technology for improving current cancer immunotherapy. Here, implantable, engineered 3D porous scaffolds are designed to generate synergistic action between myeloid‐derived suppressor cell (MDSC)‐depleting agents, which can accommodate the establishment of a permissive immunogenic microenvironment to counteract tumor‐induced immunosuppression, and cancer vaccines consisting of whole tumor lysates and nanogel‐based adjuvants, which can generate tumor antigen‐specific T cell responses. The local peritumoral implantation of the synthetic immune niche (termed immuneCare‐DISC, iCD) as a postsurgical treatment in an advanced‐stage primary 4T1 breast tumor model generates systemic antitumor immunity and prevents tumor recurrence at the surgical site as well as the migration of residual tumor cells into the lungs, resulting in 100% survival. These therapeutic outcomes are achieved through the inhibition of immunosuppressive MDSCs in tumors and spleens by releasing gemcitabine and recruitment/activation of dendritic cells, enhanced population of CD4+ and CD8+ T cells, and increased IFN‐γ production by cancer vaccines from the iCD. This combined spatiotemporal modulation of tumor‐derived immunosuppression and vaccine‐induced immune stimulation through the iCD is expected to provide an immune niche for prevention of postoperative tumor recurrence and metastasis.
Unique Bond Breaking in Crystalline Phase Change Materials and the Quest for Metavalent Bonding
Authors: Zhu Min , Cojocaru‐Mirédin Oana , Mio Antonio M. , Keutgen Jens , Küpers Michael , Yu Yuan , Cho Ju‐Young , Dronskowski Richard , Wuttig Matthias 
Published: March 2018

AbstractLaser‐assisted field evaporation is studied in a large number of compounds, including amorphous and crystalline phase change materials employing atom probe tomography. This study reveals significant differences in field evaporation between amorphous and crystalline phase change materials. High probabilities for multiple events with more than a single ion detected per laser pulse are only found for crystalline phase change materials. The specifics of this unusual field evaporation are unlike any other mechanism shown previously to lead to high probabilities of multiple events. On the contrary, amorphous phase change materials as well as other covalently bonded compounds and metals possess much lower probabilities for multiple events. Hence, laser‐assisted field evaporation in amorphous and crystalline phase change materials reveals striking differences in bond rupture. This is indicative for pronounced differences in bonding. These findings imply that the bonding mechanism in crystalline phase change materials differs substantially from conventional bonding mechanisms such as metallic, ionic, and covalent bonding. Instead, the data reported here confirm a recently developed conjecture, namely that metavalent bonding is a novel bonding mechanism besides those mentioned previously.
Highly Elastic and Ultratough Hybrid Ionic–Covalent Hydrogels with Tunable Structures and Mechanics
Authors: Yang Yanyu , Wang Xing , Yang Fei , Wang Luning , Wu Decheng 
Published: March 2018

AbstractHybrid ionically–covalently crosslinked double‐network (DN) hydrogels are attracting increasing attention on account of their self‐recovery ability and fatigue resistance, but their relative low mechanical strength and tedious performance adjustment severely limit their applications. Herein, a new strategy to concurrently fabricate hybrid ionic–covalent DN hydrogels and modulate their structures and mechanics is reported, in which an in situ formed chitosan ionic network is incorporated by post‐crosslinking the chitosan‐based composite hydrogel using multivalent anions solutions. The obtained hybrid DN hydrogels exhibit predominant mechanical properties including superior elastic modulus, high tensile strength, and ultrahigh fracture energy because of the more efficient energy dissipation of rigid short‐chain chitosan network. Notably, the swollen hydrogels still remain mechanically strong and tough even after immersion in water for 24 h. More significantly, simply changing the post‐crosslinking time can vary the compactness and rigidity of the chitosan network in situ, achieving flexible and efficient modulation of the structures and mechanics of the hybrid DN hydrogels. This study opens up a new horizon in the preparation and regulation of DN hydrogels for promising applications in tissue scaffolds, actuators, and wearable devices.
Highly Luminescent Lead Halide Perovskite Quantum Dots in Hierarchical CaF2 Matrices with Enhanced Stability as Phosphors for White Light‐Emitting Diodes
Authors: Wei Yi , Xiao Hui , Xie Zhongxi , Liang Shuang , Liang Sisi , Cai Xuechao , Huang Shanshan , Al Kheraif Abdulaziz A. , Jang Ho Seong , Cheng Ziyong , Lin Jun 
Published: March 2018

AbstractLead halide perovskite quantum dots (PQDs) have been widely recognized as highly luminescent materials for efficient optoelectronic applications owing to their fascinating electronic and optical properties. In spite of the excellent performances for the fabrication of lighting devices, the poor chemical instability greatly hampers their practical applications. The inevitable ion exchange and degradation driven from light, moisture, heat, and others limits their applications such as solid‐state light‐emitting diodes (LEDs). In this paper, the stability of PQDs is improved by integrating them in CaF2 hierarchical nanospheres (HNSs). In comparison with the pristine perovskite materials, the outstanding optical performances are well preserved. The perovskite displays a unique quantum confinement effect in the HNSs. Additionally, embedding the quantum dots in robust CaF2 matrices protects them from being damaged by moisture or light irradiation as well as anion exchange. Furthermore, white LED devices are obtained by mixing green CaF2‐CsPbBr3 composites and commercial red phosphors on a blue chip. The optimized devices show a high luminous efficacy of 62.7 lm W–1 under 20 mA current and preserve the value of 56.3 lm W–1 after working for 8 h.
Microstructures Fabricated by Two‐Photon Polymerization and Their Remote Manipulation Techniques: Toward 3D Printing of Micromachines
Authors: Lin Yang , Xu Jie 
Published: March 2018

AbstractAs a promising microfabrication method, two‐photon polymerization (TPP) underwent a rapid development for various applications in chemistry, biology, pharmaceuticals, microfluidics, and so forth. In recent years, the method has received particular attention because of its application for micromachines, including those requiring remote manipulation. Different manipulating techniques such as magnetic, optic, and acoustic manipulation are realized on TPP‐fabricated microstructures, demonstrating the great potential for further development of micromachines. Nonetheless, most of the work is still at early stages, only proofing conceptual ideas. For instance, magnetically driven microswimmers are only investigated in artificial experimental environments, and it is still challenging to tackle complex in vivo conditions. Although a long journey is still ahead for using these micromachines in daily life, it is predictable that the combination of two‐photon polymerization associated with remotely driven techniques will benefit various fields.
Photorefractive Effect in Organic–Inorganic Hybrid Perovskites and Its Application to Optical Phase Shifter
Authors: Tahara Hirokazu , Aharen Tomoko , Wakamiya Atsushi , Kanemitsu Yoshihiko 
Published: March 2018

AbstractSingle crystals of methylammonium lead trihalide perovskites with high optical transparency and well‐defined facets are grown via solution process. Using these high‐quality crystals, the photocarrier‐induced refractive‐index change is observed for the first time in organic–inorganic hybrid perovskites. The photorefractive properties are measured using a laser interferometric technique that enables to monitor the time‐resolved refractive phase shifts. It is found that these phase shifts are determined by the initial density of photogenerated carriers and they are surprisingly retained even after carrier recombination. Utilizing the extremely long‐lived phase shift, it is demonstrated that the perovskite single crystal works as a phase shifter of laser light to generate any desired polarization. Furthermore, a periodic polarization‐modulation technique is established using the time‐dependent refractive phase shift. This refractive property can be used for advanced optical applications of organic–inorganic hybrid perovskites.
Transition‐Metal‐Free Synthesis of Acridones via Base‐Mediated Intramolecular Oxidative C−H Amination
Authors: Wei Wen‐Tao , Sheng Jian‐Fei , Miao Hui , Luo Xiang , Song Xian‐Heng , Yan Ming , Zou Yong 
Published: March 2018

AbstractIntramolecular oxidative C−H amination of 2‐aminobenzophenones was achieved in the presence of potassium tert‐butoxide and dimethyl sulfoxide. A series of functionalized acridones were prepared in moderate to excellent yields in a mild, efficient, and transition‐metal‐free manner.magnified image
Direct Allylation of Active Methylene Compounds with Allylic Alcohols by Use of Palladium/Phosphine‐Borane Catalyst System
Authors: Shimizu Aika , Hirata Goki , Onodera Gen , Kimura Masanari 
Published: March 2018

AbstractThe C−C bond formation between active methylene compounds and allylic alcohols has been newly developed by using a palladium complex as a catalyst together with a phosphine‐borane ligand. The best phosphine‐borane ligand for this direct allylation has been revealed to be Ph2P(CH2)4(9‐BBN) to produce a variety of desirable allylated products in high yields.magnified image
Recent Advances in the Construction of C–N Bonds Through Coupling Reactions between Carbon Radicals and Nitrogen Radicals
Authors: Luo Junfei , Wei Wen‐Ting 
Published: March 2018

AbstractC−N bonds are widely found in natural products, medicinal molecules and multifunctional materials. In recent years, the construction of C−N bonds through a radical coupling reaction between carbon‐centered radicals with nitrogen‐centered radicals has emerged as a frontier area in organic chemistry. This review summarizes the recent advances (especially those after 2012) in radical coupling reactions that facilitate the formation of C−N bonds. The main achievements on this area are presented according to the pattern of the nitrogen‐centered radicals generated. Selected examples of substrates are listed and special attention is paid to the reaction mechanisms. Moreover, a personal outlook is described at the end.magnified image
Molybdenum‐Catalyzed Sustainable Friedländer Synthesis of Quinolines
Authors: Rubio‐Presa Rubén , Suárez‐Pantiga Samuel , Pedrosa María R. , Sanz Roberto 
Published: March 2018

AbstractPolysubstituted quinolines have been efficiently synthesized from nitroarenes and glycols, as reducing agents, under dioxomolybdenum(VI)‐catalysis. Interestingly, the waste reduction byproduct is incorporated into the final heterocycle. This method represents an efficient and sustainable variant of the Friedländer synthesis of quinolines.magnified image
Multicolor T‐Ray Imaging Using Multispectral Metamaterials
Authors: Zhou Zhitao , Zhou Tao , Zhang Shaoqing , Shi Zhifeng , Chen Ying , Wan Wenjian , Li Xinxin , Chen Xinzhong , Gilbert Corder Stephanie N. , Fu Zhanglong , Chen Liang , Mao Ying , Cao Juncheng , Omenetto Fiorenzo G. , Liu Mengkun , Li Hua , Tao Tiger H. 
Published: March 2018

AbstractRecent progress in ultrafast spectroscopy and semiconductor technology is enabling unique applications in screening, detection, and diagnostics in the Terahertz (T‐ray) regime. The promise of efficaciously operation in this spectral region is tempered by the lack of devices that can spectrally analyze samples at sufficient temporal and spatial resolution. Real‐time, multispectral T‐ray (Mul‐T) imaging is reported by designing and demonstrating hyperspectral metamaterial focal plane array (MM‐FPA) interfaces allowing multiband (and individually tunable) responses without compromising on the pixel size. These MM‐FPAs are fully compatible with existing microfabrication technologies and have low noise when operating in the ambient environment. When tested with a set of frequency switchable quantum cascade lasers (QCLs) for multicolor illumination, both MM‐FPAs and QCLs can be tuned to operate at multiple discrete THz frequencies to match analyte “fingerprints.” Versatile imaging capabilities are presented, including unambiguous identification of concealed substances with intrinsic and/or human‐engineered THz characteristics as well as effective diagnosis of cancerous tissues without notable spectral signatures in the THz range, underscoring the utility of applying multispectral approaches in this compelling wavelength range for sensing/identification and medical imaging.
A Monolithically Processed Rectifying Pixel for High‐Resolution Organic Imagers
Authors: Zalar Peter , Matsuhisa Naoji , Suzuki Toshiki , Enomoto Shintaro , Koizumi Mari , Yokota Tomoyuki , Sekino Masaki , Someya Takao 
Published: March 2018

AbstractIntegration of switching elements with sensing elements in a sensor array is a crucial platform for “sensing surfaces”. Of particular interest are imaging surfaces, especially for applications such as X‐ray imaging or fingerprint sensors. Since a photodiode loses its rectifying properties upon illumination, it requires a switching element so that meaningful data can be obtained from each individual pixel. To solve this problem, we have developed a monolithically processed rectifying pixel which enables high resolution organic imaging devices. Our organic imager has pixel pitches as small as 50 µm, with resolutions of up to 262 ppi. The pixel's individual light intensity dependent and spectral response characteristics were characterized as a function of voltage. As a total imaging system, the imageable resolution was also determined. The applicability of the imager was validated by steady state images, but also by real‐time video acquisition and by spatial photoplethysmography (PPG) measurements on the ball of a human foot.