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Rational design and controllable synthesis of nanostructured materials with unique microstructure and excellent electrochemical performance for energy storage are crucially desired. In this paper, a facile method is reported for general synthesis of hierarchically core–shell structured Ni3S2@NiMoO4 nanowires (NWs) as a binder‐free electrode for asymmetric supercapacitors. Due to the intimate contact between Ni3S2 and NiMoO4, the hierarchical structured electrodes provide a promising unique structure for asymmetric supercapacitors. The as‐prepared binder‐free Ni3S2@NiMoO4 electrode can significantly improve the electrical conductivity between Ni3S2 and NiMoO4, and effectively avoid the aggregation of NiMoO4 nanosheets, which provide more active space for storing charge. The Ni3S2@NiMoO4 electrode presents a high areal capacity of 1327.3 µAh cm−2 and 67.8% retention of its initial capacity when current density increases from 2 to 40 mA cm−2. In a two‐electrode Ni3S2@NiMoO4 // active carbon cell, the active materials deliver a high energy density of 121.5 Wh kg−1 at a power density of 2.285 kW kg−1 with excellent cycling stability. 相似文献
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Hak‐Lae Lee Haoran Wei Kiyoon Kim Hyun‐Seok Choe Hyun Park Taekyung Yu Changha Lee Jae‐Hong Kim Jae‐Hyuk Kim 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(35)
Here, a novel, versatile synthetic strategy to fabricate a yolk–shell structured material that can encapsulate virtually any functional noble metal or metal oxide nanocatalysts of any morphology in a free suspension fashion is reported. This strategy also enables encapsulation of more than one type of nanoparticle inside a single shell, including paramagnetic iron oxide used for magnetic separation. The mesoporous organosilica shell provides efficient mass transfer of small target molecules, while serving as a size exclusion barrier for larger interfering molecules. Major structural and functional advantages of this material design are demonstrated by performing three proof‐of‐concept applications. First, effective encapsulation of plasmonic gold nanospheres for localized photothermal heating and heat‐driven reaction inside the shell is shown. Second, hydrogenation catalysis is demonstrated under spatial confinement driven by palladium nanocubes. Finally, the surface‐enhanced Raman spectroscopic detection of model pollutant by gold nanorods is presented for highly sensitive environmental sensing with size exclusion. 相似文献
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Synthesis of Highly Active Sub‐Nanometer Pt@Rh Core–Shell Nanocatalyst via a Photochemical Route: Porous Titania Nanoplates as a Superior Photoactive Support 下载免费PDF全文
Wen‐Wen Zhan Qi‐Long Zhu Song Dang Zheng Liu Mitsunori Kitta Kazutomo Suenaga Lan‐Sun Zheng Qiang Xu 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(16)
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Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core–Shell Materials 下载免费PDF全文
Nima Masoumifard Rémy Guillet‐Nicolas Freddy Kleitz 《Advanced materials (Deerfield Beach, Fla.)》2018,30(16)
The term “engineered zeolitic materials” refers to a class of materials with a rationally designed pore system and active‐sites distribution. They are primarily made of crystalline microporous zeolites as the main building blocks, which can be accompanied by other secondary components to form composite materials. These materials are of potential importance in many industrial fields like catalysis or selective adsorption. Herein, critical aspects related to the synthesis and modification of such materials are discussed. The first section provides a short introduction on classical zeolite structures and properties, and their conventional synthesis methods. Then, the motivating rationale behind the growing demand for structural alteration of these zeolitic materials is discussed, with an emphasis on the ongoing struggles regarding mass‐transfer issues. The state‐of‐the‐art techniques that are currently available for overcoming these hurdles are reviewed. Following this, the focus is set on core–shell composites as one of the promising pathways toward the creation of a new generation of highly versatile and efficient engineered zeolitic substances. The synthesis approaches developed thus far to make zeolitic core–shell materials and their analogues, yolk–shell, and hollow materials, are also examined and summarized. Finally, the last section concisely reviews the performance of novel core–shell, yolk–shell, and hollow zeolitic materials for some important industrial applications. 相似文献
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Feng Wang Yongqian Gao Xuedan Ma Jennifer A. Hollingsworth Han Htoon 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(14):2892-2901
Performing time‐tagged, time‐correlated, single‐photon‐counting studies on individual colloidal nanocrystal quantum dots (NQDs), the evolution of photoluminescence (PL) intensity‐fluctuation behaviors in near‐infrared (NIR) emitting type II, InP/CdS core‐shell NQDs is investigated as a function of shell thickness. It is observed that Auger recombination and hot‐carrier trapping compete in defining the PL intensity‐fluctuation behavior for NQDs with thin shells, whereas the role of hot‐carrier trapping dominates for NQDs with thick shells. These studies further reveal the distinct ramifications of altering either the excitation fluence or repetition rate. Specifically, an increase in laser pump fluence results in the creation of additional hot‐carrier traps. Alternately, higher repetition rates cause a saturation in hot‐carrier traps, thus activating Auger‐related PL fluctuations. Furthermore, it is shown that Auger recombination of negatively charged excitons is suppressed more strongly than that of positively charged excitons because of the asymmetry in the electron‐hole confinement in type II NQDs. Thus, this study provides new understanding of how both NQD structure (shell thickness and carrier‐separation characteristics) and excitation conditions can be used to tune the PL stability, with important implications for room‐temperature single‐photon generation. Specifically, the first non‐blinking NQD capable of single‐photon emission in the near‐infrared spectral regime is described. 相似文献
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A Chemical Precipitation Method Preparing Hollow–Core–Shell Heterostructures Based on the Prussian Blue Analogs as Cathode for Sodium‐Ion Batteries 下载免费PDF全文
Yongxin Huang Man Xie Ziheng Wang Ying Jiang Ying Yao Shuaijie Li Zehua Li Li Li Feng Wu Renjie Chen 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(28)
Prussian blue and its analogs are regarded as the promising cathodes for sodium‐ion batteries (SIBs). Recently, various special structures are constructed to improve the electrochemical properties of these materials. In this study, a novel architecture of Prussian blue analogs with large cavity and multilayer shells is investigated as cathode material for SIBs. Because the hollow structure can relieve volume expansion and core–shell heterostructure can optimize interfacial properties, the complex structure materials exhibited a highly initial capacity of 123 mA h g?1 and a long cycle life. After 600 cycles, the reversible capacity of the electrode still maintains at 102 mA h g?1 without significant voltage decay, indicating a superior structure stability and sodium storage kinetics. Even at high current density of 3200 mA g?1, the electrode still delivers a considerable capacity above 52 mA h g?1. According to the electrochemical analysis and ex‐situ measurements, it can be inferred that the enhanced apparent diffusion coefficient and improved insertion/extraction performance of electrode have been obtained by building this new morphology. 相似文献
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Aiyun Meng Liuyang Zhang Bei Cheng Jiaguo Yu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(30)
Semiconductor photocatalysis is recognized as a promising strategy to simultaneously address energy needs and environmental pollution. Titanium dioxide (TiO2) has been investigated for such applications due to its low cost, nontoxicity, and high chemical stability. However, pristine TiO2 still suffers from low utilization of visible light and high photogenerated‐charge‐carrier recombination rate. Recently, TiO2 photocatalysts modified by dual cocatalysts with different functions have attracted much attention due to the extended light absorption, enhanced reactant adsorption, and promoted charge‐carrier‐separation efficiency granted by various cocatalysts. Recent progress on the component and structural design of dual cocatalysts in TiO2 photocatalysts is summarized. Depending on their components, dual cocatalysts decorated on TiO2 photocatalysts can be divided into the following categories: bimetallic cocatalysts, metal–metal oxide/sulfide cocatalysts, metal–graphene cocatalysts, and metal oxide/sulfide–graphene cocatalysts. Depending on their architecture, they can be categorized into randomly deposited binary cocatalysts, facet‐dependent selective‐deposition binary cocatalysts, and core–shell structural binary cocatalysts. Concluding perspectives on the challenges and opportunities for the further exploration of dual cocatalyst–modified TiO2 photocatalysts are presented. 相似文献
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Jinyou Xu Katya Rechav Ronit Popovitz‐Biro Iftach Nevo Yishay Feldman Ernesto Joselevich 《Advanced materials (Deerfield Beach, Fla.)》2018,30(20)
1D core–shell heterojunction nanostructures have great potential for high‐performance, compact optoelectronic devices owing to their high interface area to volume ratio, yet their bottom‐up assembly toward scalable fabrication remains a challenge. Here the site‐controlled growth of aligned CdS–CdSe core–shell nanowalls is reported by a combination of surface‐guided vapor–liquid–solid horizontal growth and selective‐area vapor–solid epitaxial growth, and their integration into photodetectors at wafer‐scale without postgrowth transfer, alignment, or selective shell‐etching steps. The photocurrent response of these nanowalls is reduced to 200 ns with a gain of up to 3.8 × 103 and a photoresponsivity of 1.2 × 103 A W?1, the fastest response at such a high gain ever reported for photodetectors based on compound semiconductor nanostructures. The simultaneous achievement of sub‐microsecond response and high‐gain photocurrent is attributed to the virtues of both the epitaxial CdS–CdSe heterojunction and the enhanced charge‐separation efficiency of the core–shell nanowall geometry. Surface‐guided nanostructures are promising templates for wafer‐scale fabrication of self‐aligned core–shell nanostructures toward scalable fabrication of high‐performance compact photodetectors from the bottom‐up. 相似文献
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Epitaxial Growth of Lattice‐Mismatched Core–Shell TiO2@MoS2 for Enhanced Lithium‐Ion Storage 下载免费PDF全文
Rui Dai Anqi Zhang Zhichang Pan Abdullah M. Al‐Enizi Ahmed A. Elzatahry Linfeng Hu Gengfeng Zheng 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(20):2792-2799
Core–shell structured nanohybrids are currently of significant interest due to their synergetic properties and enhanced performances. However, the restriction of lattice mismatch remains a severe obstacle for heterogrowth of various core–shells with two distinct crystal structures. Herein, a controlled synthesis of lattice‐mismatched core–shell TiO2@MoS2 nano‐onion heterostructures is successfully developed, using unilamellar Ti0.87O2 nanosheets as the starting material and the subsequent epitaxial growth of MoS2 on TiO2. The formation of these core–shell nano‐onions is attributed to an amorphous layer‐induced heterogrowth mechanism. The number of MoS2 layers can be well tuned from few to over ten layers, enabling layer‐dependent synergistic effects. The core–shell TiO2@MoS2 nano‐onion heterostructures exhibit significantly enhanced energy storage performance as lithium‐ion battery anodes. The approach has also been extended to other lattice‐mismatched systems such as TiO2@MoSe2, thus suggesting a new strategy for the growth of well‐designed lattice‐mismatched core–shell structures. 相似文献
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Bipolar Carrier Transfer Channels in Epitaxial Graphene/SiC Core–Shell Heterojunction for Efficient Photocatalytic Hydrogen Evolution 下载免费PDF全文
Wei Lu Da Wang Liwei Guo Yuping Jia Manping Ye Jiao Huang Zhilin Li Yuan Peng Wenxia Yuan Xiaolong Chen 《Advanced materials (Deerfield Beach, Fla.)》2015,27(48):7986-7991
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A Monodispersed Spherical Zr‐Based Metal–Organic Framework Catalyst,Pt/Au@Pd@UIO‐66, Comprising an Au@Pd Core–Shell Encapsulated in a UIO‐66 Center and Its Highly Selective CO2 Hydrogenation to Produce CO 下载免费PDF全文
Zhizhong Zheng Haitao Xu Zhenliang Xu Jianping Ge 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(5)
A Zr‐based metal–organic framework (MOF) catalyst, Pt/Au@Pd@UIO‐66, is assembled, where UIO‐66 is Zr6O4(OH)4(BDC)6 (BDC = 1,4‐benzenedicarboxylate). The gold nanoparticles (NPs) act as the core for the epitaxial growth of Pd shells, and the core–shell monodispersed nanosphere Au@Pd is encapsulated into UIO‐66 to control its morphology and impart nanoparticle functionality. The microporous nature of UIO‐66 assists the adsorption of Pt NPs, which in turn enhances the interaction between NPs and UIO‐66, favoring the formation of isolated and well‐dispersed Pt NP active sites. This MOF exhibits high catalytic activity and CO product selectivity for the reverse‐water–gas‐shift reaction in a fixed‐bed flow reactor. 相似文献
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CdS@SiO2 Core–Shell Electroluminescent Nanorod Arrays Based on a Metal–Insulator–Semiconductor Structure 下载免费PDF全文
Chunfeng Wang Dengfeng Peng Jing Zhao Rongrong Bao Tianfeng Li Li Tian Lin Dong Changyu Shen Caofeng Pan 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(41):5734-5740
Enormous advancement has been achieved in the field of one‐dimensional (1D) semiconductor light‐emitting devices (LEDs), however, LEDs based on 1D CdS nanostructures have been rarely reported. The fabrication of CdS@SiO2 core–shell nanorod array LEDs based on a Au–SiO2–CdS metal–insulator–semiconductor (MIS) structure is presented. The MIS LEDs exhibit strong yellow emission with a low threshold voltage of 2.7 V. Electroluminescence with a broad emission ranging from 450 nm to 800 nm and a shoulder peak at 700 nm is observed, which is related to the defects and surface states of the CdS nanorods. The influence of the SiO2 shell thickness on the electroluminescence intensity is systematically investigated. The devices have a high light‐emitting spatial resolution of 1.5 μm and maintain an excellent emission property even after shelving at room temperature for at least three months. Moreover, the fabrication process is simple and cost effective and the MIS device could be fabricated on a flexible substrate, which holds great potential for application as a flexible light source. This prototype is expected to open up a new route towards the development of large‐scale light‐emitting devices with excellent attributes, such as high resolution, low cost, and good stability. 相似文献
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Hexagonal@Cubic CdS Core@Shell Nanorod Photocatalyst for Highly Active Production of H2 with Unprecedented Stability 下载免费PDF全文
Kui Li Min Han Rong Chen Shun‐Li Li Shuai‐Lei Xie Chengyu Mao Xianhui Bu Xue‐Li Cao Long‐Zhang Dong Pingyun Feng Ya‐Qian Lan 《Advanced materials (Deerfield Beach, Fla.)》2016,28(40):8906-8911
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Metal Hydride Nanoparticles with Ultrahigh Structural Stability and Hydrogen Storage Activity Derived from Microencapsulated Nanoconfinement 下载免费PDF全文
Jiguang Zhang Yunfeng Zhu Huaijun Lin Yana Liu Yao Zhang Shenyang Li Zhongliang Ma Liquan Li 《Advanced materials (Deerfield Beach, Fla.)》2017,29(24)
Metal hydrides (MHs) have recently been designed for hydrogen sensors, switchable mirrors, rechargeable batteries, and other energy‐storage and conversion‐related applications. The demands of MHs, particular fast hydrogen absorption/desorption kinetics, have brought their sizes to nanoscale. However, the nanostructured MHs generally suffer from surface passivation and low aggregation‐resisting structural stability upon absorption/desorption. This study reports a novel strategy named microencapsulated nanoconfinement to realize local synthesis of nano‐MHs, which possess ultrahigh structural stability and superior desorption kinetics. Monodispersed Mg2NiH4 single crystal nanoparticles (NPs) are in situ encapsulated on the surface of graphene sheets (GS) through facile gas–solid reactions. This well‐defined MgO coating layer with a thickness of ≈3 nm efficiently separates the NPs from each other to prevent aggregation during hydrogen absorption/desorption cycles, leading to excellent thermal and mechanical stability. More interestingly, the MgO layer shows superior gas‐selective permeability to prevent further oxidation of Mg2NiH4 meanwhile accessible for hydrogen absorption/desorption. As a result, an extremely low activation energy (31.2 kJ mol–1) for the dehydrogenation reaction is achieved. This study provides alternative insights into designing nanosized MHs with both excellent hydrogen storage activity and thermal/mechanical stability exempting surface modification by agents. 相似文献