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991.
Teng Zhai Shuo Sun Xiaojing Liu Chaolun Liang Gongming Wang Hui Xia 《Advanced materials (Deerfield Beach, Fla.)》2018,30(12)
The insertion/deinsertion mechanism enables plenty of charge‐storage sites in the bulk phase to be accessible to intercalated ions, giving rise to at least one more order of magnitude higher energy density than the adsorption/desorption mechanism. However, the sluggish ion diffusion in the bulk phase leads to several orders of magnitude slower charge‐transport kinetics. An ideal energy‐storage device should possess high power density and large energy density simultaneously. Herein, surface‐modified Fe2O3 quantum dots anchored on graphene nanosheets are developed and exhibit greatly enhanced pseudocapacitance via fast dual‐ion‐involved redox reactions with both large specific capacity and fast charge/discharge capability. By using an aqueous Na2SO3 electrolyte, the oxygen‐vacancy‐tuned Fe2O3 surface greatly enhances the absorption of SO32? anions that majorly increase the surface pseudocapacitance. Significantly, the Fe2O3‐based electrode delivers a high specific capacity of 749 C g?1 at 5 mV s?1 and retains 290 C g?1 at an ultrahigh scan rate of 3.2 V s?1. With a novel dual‐electrolyte design, a 2 V Fe2O3/Na2SO3//MnO2/Na2SO4 asymmetric supercapacitor is constructed, delivering a high energy density of 75 W h kg?1 at a power density of 3125 W kg?1. 相似文献
992.
Wei Zhao Yongmei Zhao Qingfu Wang Tianqing Liu Jingjiang Sun Run Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(45)
Engineering of smart photoactivated nanomaterials for targeted drug delivery systems (DDS) has recently attracted considerable research interest as light enables precise and accurate controlled release of drug molecules in specific diseased cells and/or tissues in a highly spatial and temporal manner. In general, the development of appropriate light‐triggered DDS relies on processes of photolysis, photoisomerization, photo‐cross‐linking/un‐cross‐linking, and photoreduction, which are normally sensitive to ultraviolet (UV) or visible (Vis) light irradiation. Considering the issues of poor tissue penetration and high phototoxicity of these high‐energy photons of UV/Vis light, recently nanocarriers have been developed based on light‐response to low‐energy photon irradiation, in particular for the light wavelengths located in the near infrared (NIR) range. NIR light‐triggered drug release systems are normally achieved by using two‐photon absorption and photon upconversion processes. Herein, recent advances of light‐responsive nanoplatforms for controlled drug release are reviewed, covering the mechanism of light responsive small molecules and polymers, UV and Vis light responsive nanocarriers, and NIR light responsive nanocarriers. NIR‐light triggered drug delivery by two‐photon excitation and upconversion luminescence strategies is also included. In addition, the challenges and future perspectives for the development of light triggered DDS are highlighted. 相似文献
993.
994.
Chemical Patterning of High‐Mobility Semiconducting 2D Bi2O2Se Crystals for Integrated Optoelectronic Devices 下载免费PDF全文
Jinxiong Wu Yujing Liu Zhenjun Tan Congwei Tan Jianbo Yin Tianran Li Teng Tu Hailin Peng 《Advanced materials (Deerfield Beach, Fla.)》2017,29(44)
Patterning of high‐mobility 2D semiconducting materials with unique layered structures and superb electronic properties offers great potential for batch fabrication and integration of next‐generation electronic and optoelectronic devices. Here, a facile approach is used to achieve accurate patterning of 2D high‐mobility semiconducting Bi2O2Se crystals using dilute H2O2 and protonic mixture acid as efficient etchants. The 2D Bi2O2Se crystal after chemical etching maintains a high Hall mobility of over 200 cm2 V?1 s?1 at room temperature. Centimeter‐scale well‐ordered arrays of 2D Bi2O2Se with tailorable configurations are readily obtained. Furthermore, integrated photodetectors based on 2D Bi2O2Se arrays are fabricated, exhibiting excellent air stability and high photoresponsivity of ≈2000 A W?1 at 532 nm. These results are one step towards the practical application of ultrathin 2D integrated digital and optoelectronic circuits. 相似文献
995.
Liang Cheng Xianwen Wang Fei Gong Teng Liu Zhuang Liu 《Advanced materials (Deerfield Beach, Fla.)》2020,32(13):1902333
2D nanomaterials with unique nanosheet structures, large surface areas, and extraordinary physicochemical properties have attracted tremendous interest. In the area of nanomedicine, research on graphene and its derivatives for diverse biomedical applications began as early as 2008. Since then, many other types of 2D nanomaterials, including transition metal dichalcogenides, transition metal carbides, nitrides and carbonitrides, black phosphorus nanosheets, layered double hydroxides, and metal–organic framework nanosheets, have been explored in the area of nanomedicine over the past decade. In particular, a large surface area makes 2D nanomaterials highly efficient drug delivery nanoplatforms. The unique optical and/or X-ray attenuation properties of 2D nanomaterials can be harnessed for phototherapy or radiotherapy of cancer. Furthermore, by integrating 2D nanomaterials with other functional nanoparticles or utilizing their inherent physical properties, 2D nanomaterials may also be engineered as nanoprobes for multimodal imaging of tumors. 2D nanomaterials have shown substantial potential for cancer theranostics. Herein, the latest progress in the development of 2D nanomaterials for cancer theranostic applications is summarized. Current challenges and future perspectives of 2D nanomaterials applied in nanomedicine are also discussed. 相似文献
996.
SrTiO3作为钛矿型金属氧化物半导体,具有环境友好、原料来源丰富等优点。本研究发现了一种制备高新热电性能SrTiO3材料的新工艺,对比固相反应法直接烧制的SrTiO3陶瓷,采用本工艺的PAS+埋烧热处理方法可以降低制备反应温度,并且所得材料的功率因子得到显著提高。该项发现主要研究了在此工艺下制备的不同La、Nb掺杂比(5%-15%)的样品性能变化情况。结果表明,该工艺下制备的SrTiO3样品中La15Nb15样品在873K时的最大功率因子可达1.279mW·m-1·K-1。但是部分样品热导率也会出现一定程度的增加。综合效果是材料热电优值ZT得以提升,在873K时La10Nb5样品的ZT值达到了0.28。 相似文献
998.
Run Hu Shiyao Huang Meng Wang Xiaobing Luo Junichiro Shiomi Cheng‐Wei Qiu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(25)
Artificially structured thermal metamaterials provide an unprecedented possibility of molding heat flow that is drastically distinct from the conventional heat diffusion in naturally conductive materials. The Laplacian nature of heat conduction makes the transformation thermotics, as a design principle for thermal metadevices, compatible with transformation optics. Various functional thermal devices, such as thermal cloaks, concentrators, and rotators, have been successfully demonstrated. How far can it possible go beyond just realizing a heat‐distribution function in a thermal metadevice? Herein, the concept of encrypted thermal printing is proposed and experimentally validated, which could conceal encrypted information under natural light and present static or dynamic messages in an infrared image. Regionalization transformation is developed for structuring thermal metamaterial‐strokes as infrared signatures, enabling letters of the alphabet to be written, paintings to be drawn, movies to be made, and information to be displayed. This strategy successfully demonstrates an extreme level of manipulation of heat flow for encryption, illusions, and messaging. 相似文献
999.
Functional materials are the key enabling factor in the development of clean energy technologies. Materials of particular interest, which are reviewed herein, are a class of hydrogenous compound having the general formula of M(XHn)m, where M is usually a metal cation and X can be Al, B, C, N, O, transition metal (TM), or a mixture of them, which sets up an iono‐covalent or covalent bonding with H. M(XHn)m is generally termed as a complex hydride by the hydrogen storage community. The rich chemistry between H and B/C/N/O/Al/TM allows complex hydrides of diverse composition and electronic configuration, and thus tunable physical and chemical properties, for applications in hydrogen storage, thermal energy storage, ion conduction in electrochemical devices, and catalysis in fuel processing. The recent progress is reviewed here and strategic approaches for the design and optimization of complex hydrides for the abovementioned applications are highlighted. 相似文献
1000.
随着可再生能源及能源转换技术的快速发展, 热电材料在发电及制冷领域的应用前景受到越来越广泛的关注。发展具有高热电优值材料的重要性日益突出, 如何获得低晶格热导率是热电材料的研究重点之一。本文阐述了热容、声速及弛豫时间对晶格热导率的影响, 介绍了本征低热导率热电材料所具有的典型特征, 如强非谐性、弱化学键、本征共振散射及复杂晶胞结构等, 并分析了通过多尺度声子散射降低已有热电材料晶格热导率的方法, 其中包括点缺陷散射、位错散射、晶界散射、共振散射、电声散射等多种散射机制。此外, 总结了几种预测材料最小晶格热导率的理论模型, 对快速筛选具有低晶格热导率的热电材料具有一定的理论指导意义。最后, 展望了如何获得低热导率热电材料的有效途径。 相似文献