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161.
Van der Waals Heterostructures Comprised of Ultrathin Polymer Nanosheets for Efficient Z‐Scheme Overall Water Splitting 下载免费PDF全文
Lei Wang Dr. Xusheng Zheng Liang Chen Prof. Yujie Xiong Prof. Hangxun Xu 《Angewandte Chemie (International ed. in English)》2018,57(13):3454-3458
Inspired by natural photosynthesis, Z‐scheme photocatalytic systems are very appealing for achieving efficient overall water splitting. Developing metal‐free Z‐scheme photocatalysts for overall water splitting, however, still remains challenging. The construction of polymer‐based van der Waals heterostructures as metal‐free Z‐scheme photocatalytic systems for overall water splitting is described using aza‐fused microporous polymers (CMP) and C2N ultrathin nanosheets as O2‐ and H2‐evolving catalysts, respectively. Although neither polymer is able to split pure water using visible light, a 2:1 stoichiometric ratio of H2 and O2 was observed when aza‐CMP/C2N heterostructures were used. A solar‐to‐hydrogen conversion efficiency of 0.23 % was determined, which could be further enhanced to 0.40 % by using graphene as the solid electron mediator to promote the interfacial charge‐transfer process. This study highlights the potential of polymer photocatalysts for overall water splitting. 相似文献
162.
MoS2‐on‐MXene Heterostructures as Highly Reversible Anode Materials for Lithium‐Ion Batteries 下载免费PDF全文
Chi Chen Dr. Xiuqiang Xie Prof. Babak Anasori Asya Sarycheva Dr. Taron Makaryan Dr. Mengqiang Zhao Patrick Urbankowski Prof. Ling Miao Prof. Jianjun Jiang Prof. Yury Gogotsi 《Angewandte Chemie (International ed. in English)》2018,57(7):1846-1850
Two‐dimensional (2D) heterostructured materials, combining the collective advantages of individual building blocks and synergistic properties, have spurred great interest as a new paradigm in materials science. The family of 2D transition‐metal carbides and nitrides, MXenes, has emerged as an attractive platform to construct functional materials with enhanced performance for diverse applications. Here, we synthesized 2D MoS2‐on‐MXene heterostructures through in situ sulfidation of Mo2TiC2Tx MXene. The computational results show that MoS2‐on‐MXene heterostructures have metallic properties. Moreover, the presence of MXene leads to enhanced Li and Li2S adsorption during the intercalation and conversion reactions. These characteristics render the as‐prepared MoS2‐on‐MXene heterostructures stable Li‐ion storage performance. This work paves the way to use MXene to construct 2D heterostructures for energy storage applications. 相似文献
163.
Yu-lin Chen Ming-ling Li Yi-ming Wu Si-jia Li Yue Lin Dong-xue Du Huai-yi Ding Nan Pan Xiao-ping Wang 《化学物理学报(中文版)》2017,30(3):325-332
Two-dimensional transition metal dichalcogenides heterostructures have stimulated wide interest not only for the fundamental research,but also for the application of next generation electronic and optoelectronic devices.Herein,we report a successful two-step chemical vapor deposition strategy to construct vertically stacked van der Waals epitaxial In2Se3/MoSe2 heterostructures.Transmission electron microscopy characterization reveals clearly that the In2Se3 has well-aligned lattice orientation with the substrate of monolayer MoSe2.Due to the interaction between the In2Se3 and MoSe2 layers,the heterostructure shows the quenching and red-shift of photoluminescence.Moreover,the current rectification behavior and photovoltaic effect can be observed from the heterostructure,which is attributed to the unique band structure alignment of the heterostructure,and is further confirmed by Kevin probe force microscopy measurement.The synthesis approach via van der Waals epitaxy in this work can expand the way to fabricate a variety of two-dimensional heterostructures for potential applications in electronic and optoelectronic devices. 相似文献
164.
Daisuke Iida Yasunari Kondo Mihoko Sowa Toru Sugiyama Motoaki Iwaya Tetsuya Takeuchi Satoshi Kamiyama Isamu Akasaki 《固体物理学:研究快报》2013,7(3):211-214
Strain relaxation in a GaInN/GaN heterostructure is analyzed by combining in situ X‐ray diffraction (XRD) monitoring and ex situ observations. Two different characteristic thicknesses of GaInN films are defined by the evolution of in situ XRD from the full width at half‐maximum of symmetric (0002) diffraction as a function of GaInN thickness. This in situ XRD measurement enables to clearly observe the critical thicknesses corresponding to strain relaxation in the GaInN/GaN heterostructure caused by the formation of surface pits with bent threading dislocations and the generation of misfit dislocations on GaInN during growth. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
165.
Morphologies à la carte: A kinetic control strategy has been utilized to fabricate bimetallic nanoparticles. Using cubic Pd nanocrystals as seeds and a syringe pump that enables precise control over precursor injection rate, it is possible to synthesize Pd-Ag bimetallic nanoparticles with tailored shapes (see picture: dimers, eccentric hybrid bars, and core-shell structures) and tunable localized surface plasmon resonances. 相似文献
166.
Komban R Klare JP Voss B Nordmann J Steinhoff HJ Haase M 《Angewandte Chemie (International ed. in English)》2012,51(26):6506-6510
Doped nanocrystals of NaYF(4) and NaGdF(4) are currently studied as upconversion luminescence markers and magnetic resonance imaging contrast agents. An EPR investigation on the growth mechanism of NaYF(4):Gd and NaGdF(4) nanocrystals showed that these nanomaterials grow in the standard oleic acid-based reaction medium by a dissolution/recrystallization mechanism and not by the aggregation or oriented attachment of smaller particles. 相似文献
167.
Atomically Precise Transformations and Millimeter‐Scale Patterning of Nanoscale Assemblies by Ambient Electrospray Deposition 下载免费PDF全文
Anirban Som Depanjan Sarkar Sisira Kanhirathingal Thalappil Pradeep 《Particle & Particle Systems Characterization》2017,34(7)
The performance of semiconductor devices can be fine‐tuned through chemical transformation of their nanostructured components. Such transformations are often carried out in controlled conditions. Herein, the use of electrospray deposition of metal ions from solutions in air is reported, to bring about chemical transformations across mm2‐sized areas of nanostructures. This is illustrated with monolayer assemblies of ultrathin tellurium nanowires (NWs). The process does not require any reducing agent and can transform the NWs chemically, in the solid state itself, under ambient conditions. By using suitable masks, the beam of ions can be patterned to localize such transformations with nanometer precision to obtain aligned multiphasic NWs, containing atomically precise phase boundaries. By controlling the time of exposure of the spray, the scope of the process is further expanded to produce tellurium‐metal telluride core–shell NWs. The method described here represents a crucial step for ambient processing of nanostructured components, useful for applications such as semiconductor device fabrication. 相似文献
168.
Fabrication and optical properties of type‐II InP/InAs nanowire/quantum‐dot heterostructures 下载免费PDF全文
The growth and optical properties of InAs quantum dots on a pure zinc blende InP nanowire are investigated. The quantum dots are formed in Stranski–Krastanov mode and exhibit pure zinc blende crystal structure. A substantial blueshift of the dots peak with a cube‐root dependence on the excitation power is observed, suggesting a type‐II band alignment. The peak position of dots initially red‐shifts and then blue‐shifts with increasing temperature, which is attributed to the carrier redistribution among the quantum dots. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
169.
170.
Epitaxial La1−x
Pb
x
MnO3 (LPMO) thin films, grown on (100) SrTiO3 substrates by laser ablation technique at different temperatures between 600 and 850°C, have been characterized for electrical
and magnetic properties. The temperature dependence of resistivity showed that the metal-insulator transition temperature
(T
MI) decreases with increasing substrate temperature, which has been attributed to decrease in Pb content in the filsm. The YBa2Cu3O
x
/La1−x
MnO3 heterostructures, exhibiting both superconductivity and ferromagnetism, have been fabricated. 相似文献