Formation and Growth of Silver Nanocubes upon Nanosecond Pulsed Laser Irradiation: Effects of Laser Intensity and Irradiation Time

Silver nanoparticles (AgNPs) were fabricated by repetitive irradiation of near ultraviolet (UV) nanosecond laser pulses (355 nm, 5 ns) in an aqueous solution of silver nitrate in the absence of stabilizing agents. A broad absorption peak was observed in the visible region showing the formation of a variety of AgNPs in the solution. Among the variety of products, it was found that silver nanocubes (AgNCs) grew in size with longer laser irradiation time. The size of AgNCs also increased with higher laser intensity. The average size of AgNCs, investigated by a scanning electron microscope (SEM) was in the range of 75 - 200 nm. The number of reduced atoms in AgNCs as a function of laser intensity showed that the AgNCs are apparently produced by a four photon process, implying that the formation of dimer silver atoms is essential for the formation.

Porous Y_2O_3 microcubes:synthesis and characterization

In this work, a facile route using a simple solvothermal reaction and sequential heat treatment process to prepare porous Y2O3 microcubes is presented. The as-synthesized products were characterized by X-ray powder diffraction （XRD）, scanning electronic microscope （SEM）, energy dispersive spectrometer （EDS）, thermogravimetric analysis （TG）, and differential thermal analysis （DTA）. The thermal decomposition process of the Y203 precursor was investigated. SEM results demonstrated that the as-prepared porous Y203 microcubes were with an average width of about 20 μm and thickness of about 8μm. It was found that the morphology of the Y2O3 precursor could be readily tuned by varying the molar ratio of S2O2- to y3＋. Y203：Eu3＋ （6.6%） microcubes were also prepared and their photoluminescence properties were investigated.

Microwave-assisted synthesis of photoluminescent glutathione-capped Au/Ag nanoclusters： A unique sensor-on-a-nanoparticle for metal ions, anions, and small molecules

Even though great advances have been achieved in the synthesis of luminescent metal nanoclusters, it is still challenging to develop metal nanoclusters with high quantum efficiency as well as multiple sensing functionalities. Here, we demonstrate the rapid preparation of glutathione-capped Au/Ag nanoclusters （GS-Au/Ag NCs） using microwave irradiation and their unique sensing capacities. Compared to bare GS-Au NCs, the doped Au/Ag NCs possess an enhanced quantum yield （7.8% compared to 2.2% for GS-Au NCs）. Several characterization techniques were used to elucidate the atomic composition, particulate character, and electronic structure of the fabricated NCs. According to the X-ray photoelectron spectroscopy （XPS） and X-ray absorption near-edge structure （XANES） spectra, a significant amount of Au exists in the oxidized state as Au（I）, and the Ag atoms are positively charged. In contrast to those nanoclusters that detect only one analyte, the GS-Au/Ag NCs can be used as a versatile sensor for metal ions, anions, and small molecules. In this manner, the NCs can be regarded as a unique sensor-on-a-nanoparticle.

Binary synergistic enhancement of dielectric and microwave absorption properties： A composite of arm symmetrical PbS dendrites and polyvinylidene fluoride

Arm symmetrical PbS dendrite （ASD-PbS） nanostructures can be prepared on a large scale by a solvothermal process. The ASD-PbSs exhibit a three-dimensional symmetrical structure, and each dendrite grows multiple branches on the main trunk. Such unique ASD-PbSs can be combined with polyvinylidene fluoride （PVDF） to prepare a composite material with enhanced dielectric and microwave-absorption properties. A detailed investigation of the dependence of the dielectric properties on the frequency and temperature shows that the ASD-PbS/PVDF composite has an ultrahigh dielectric constant and a low percolation threshold. The dielectric permittivity is as high as 1,548 when the concentration of the ASD-PbS filler reaches 13.79 vol.% at 102 Hz, which is 150 times larger than that of pure PVDF, while the composite is as flexible as pure PVDF. Furthermore, the maximum reflection loss can reach -36.69 dB at 16.16 GHz with a filler content of only 2 wt.%, which indicates excellent microwave absorption. The loss mechanism is also elucidated. The present work demonstrates that the addition of metal sulfide microcrystals to polymer matrix composites provides a useful method for improving the dielectric and microwave-absorption properties.

Understanding the stability and reactivity of ultrathin tellurium nanowires in solution： An emerging platform for chemical transformation and material design

nanomaterials 的稳定性和反应具有为他们的申请的关键重要性，但是稳定性的长期的效果和在实际条件下面的 nanomaterials 的反应仍然不是理解的井。在这研究，我们首先建立了全面策略通过一个加速的氧化过程在水的答案作为模型材料与 ultrathin 碲 nanowires TeNWs 从反应动力学的观点调查高度反应的 nanomaterial 的稳定性。这允许我们用在不同条件下面在动态氧化过程期间捕获的中间的 nanostructures 由一个化学转变过程为另外的唯一的一个维的 nanostructures 的设计和合成建议一条新途径。实质上， ultrathin TeNWs 的氧化是包含液体，气体和稳固的阶段的煤气固体的反应。在水的答案的 ultrathin TeNWs 的氧化进程能被划分成三个阶段，这被表明了，也就是，限制的氧， ultrathin TeNWs 限制和质量转移限制阶段的抵抗。为 ultrathin TeNWs 的明显的氧化动力学是近似与第一顺序反应动力学一致当模特儿并且有象 13.53 kJ 一样低的一个明显的激活精力 ? 敤 ? 楤? 敗捩?楥慬? 瑳敨楳? 畡 ? 瑥慷 ?┰瘠牥 k 吗？？

A Robust Wood-inspired Catalytic System for Highly Efficient Reduction of 4-Nitrophenol

Porous solid scaffolds play key roles in preventing nanocatalysts from agglomeration,greatly maintaining the catalytic efficiency and stability of nanocatalysts.However,facile preparation of robust scaffolds with high mass transfer efficiency for loading nanocatalysts remains a major challenge.Here,we fabricate a wood-inspired shape-memory chitosan scaffold for loading Au nanoparticles to reduce 4-nitrophenol via a simple“freeze-casting and dip-adsorption”approach.The obtained catalytic scaffold highly resembles the unidirectional microchannel structure of natural wood,resulting in robust mechanical properties and outstanding water absorption capacity.Additionally,Au nanoparticles can be firmly and uniformly anchored on the inner surface of these microchannels via electrostatic interaction,forming numerous microreactors.This catalytic system exhibits a high 4-nitrophenol conversion rate of 99%in 5 s and impressive catalytic stability even after continuously treating with more than 3 L of highly concentrated 4-nitrophenol solution(1 mmol/L).Therefore,the wood-like catalytic system presented here demonstrates the potential to be applied in the field of water treatment and environmental protection.

Dyeing bacterial cellulose pellicles for energetic heteroatom doped carbon nanofiber aerogels

精力危机和环境污染是那个人文学科将面对为的严肃的挑战长期。尽管有巨大的努力，环境地友好的方法的发展仍然正在质问制作新精力材料。第一次，这里，我们报导新策略制作各种各样的做的碳 nanofiber (CNF ) 由细菌的纤维素(BC ) 的热分解的 aerogels 与不同有毒的器官的染料吸附了或被染的薄皮。建议策略使把有毒的染料从废水移开然后综合可能把染的 BC 薄皮用作先锋的做的 CNF aerogels。与为准备的另外的报导过程相比， heteroatom 做了碳(HDC ) nanomaterials，现在的合成方法有一些重要优点例如是绿的，一般、便宜、容易可伸缩。而且，象为氧减小反应(ORR ) 的 electrocatalysts 并且作为为 supercapacitors 的电极材料潜在的同样准备的做的 CNF aerogels 展览伟人。

One-dimensional (1D) europium coordination polymer wires:Synthesis,characterization and photoluminescence properties

1D europium coordination polymer wires were successfully prepared by reacting europium chloride with tributyl phosphate(TBP) at 160 oC for 12 h. The products were characterized by XRD,IR,TG,DTA,SEM,and EDS. SEM results showed that the wires were with diameters ranging from several hundreds of nanometers to ～5 μm and lengths going up to several hundreds of micrometers. Influencing factors such as the dosage of reactants and reaction time on the preparation were systematically investigated. Strong emission centering at 590 nm was realized in the coordination polymer wires on excitation at 395 nm.

In situ assembly of magnetic nanocrystals/graphene oxide nanosheets on tumor cells enables efficient cancer therapy

Owing to the stimulus-responsive and dynamic properties,magnetism-driven assembly of building blocks to form ordered structures is always a marvelous topic.While abundant magnetic assemblies have been developed in ideal physical and chemical conditions,it remains a challenge to realize magnetic assembly in complicated biological systems.Herein,we report a kind of biomacromolecule-modified magnetic nanosheets,which are mainly composed of superparamagnetic graphene oxide(Y-Fe2O3@GO),the tumor-targeting protein transferrin(TF),and the mitochondrion-targeting peptide(MitP).Such large-size nanosheets(0.5-1μm),noted as L-Fe2O3@GO-MitP-TF,can successfully in s itu assemble on the surface of tumor cells in a size-dependent and tumor cell-specific way,leading to severe inhibition of nutrient uptake for the tumor cells.More significantly,the nanostructures could efficiently confine the tumor cells,preventing both invasion and metastasis of tumor cells both in vitro and in vivo.Moreover,the 2D assemblies could remarkably disrupt the mitochondria and induce apoptosis,remarkably eradicating tumors under near-infrared(NIR)irradiation.This study sheds light on the development of new nano-systems for efficient cancer therapy and other biomedical applications.

Anisotropic nanowire growth via a self-confined amorphous template process： A reconsideration on the role of amorphous calcium carbonate

Calcium carbonate crystals with various morphologies have been found in a variety of biospecimens and artificially synthesized structures. Usually, the diversity in morphology can be attributed to different types of interactions between the specific crystal faces and the environment or the templates used for the growth of CaCO3 crystals. On the other hand, isotropic amorphous calcium carbonate （ACC） has been recognized as the precursor of other crystalline calcium carbonate forms for both in vivo and in vitro systems. However, here we propose a self-confined amorphous template process leading to the anisotropic growth of single-crystalline calcite nanowires. Initiated by the assembly of precipitated nanoparticles, the calcite nanowires grew via the continuous precipitation of partly crystallized ACC nanodroplets onto their tips. Then, the crystalline domains in the tip, which were generated from the partly crystallized nanodroplets, coalesced in the interior of the nanowire to form a single-crystalline core. The ACC domains were left outside and spontaneously formed a protective shell to retard the precipitation of CaCO3 onto the side surface of the nanowire and thus guided the highly anisotropic growth of nanowires as a template.

Hydrazine-Cadmium Tellurite Hybrid Microcrystals: An Efficient Precursor to Porous Cadmium Telluride and Tellurium Architectures Through Its Thermal Decomposition

Well-defined platelet-like hydrazine-cadmium tellurite hybrid microcrystals have been synthesized by a solvothermal reaction of cadmium chloride,sodium tellurite,and hydrazine hydrate in a mixed solvent containing n-propylamine and deionized water.The formula of the hybrid platelet-like microcrystals has been proposed based on a combination of powder X-ray diffraction pattern(PXRD),elemental analysis,thermogravimetic analysis(TGA),and X-ray photoelectron spectroscopy(XPS).Controlled thermal decomposition of this hybrid precursor can lead to the formation of porous platelet-like microarchitectures.Pure porous cadmium telluride architectures were obtained by using hydrochloric acid to dissolve CdTeO3 remaining in the sample after thermal decomposition at 450°C.In addition,unique nanoporous tellurium architectures were obtained by using hydrochloric acid to dissolve the amorphous Cd(N2H4)TeO3 formed after thermal decomposition at 300°C,followed by an in situ topotactic reaction between the residual three-dimensional(3-D)skeleton of cadmium telluride nanocrystallites and−23TeO.Brunauer-Emmett-Teller(BET)analysis and a study of the optical properties of these porous cadmium telluride and tellurium materials have also been carried out.

Joule-heated carbonized melamine sponge for high-speed absorption of viscous oil spills

Introducing heating function to oil sorbents opens up a new pathway to the fast cleanup of viscous crude oil spills in situ.The oil sorption speed increases with the rise of the temperature,thus oil sorbents with high heating temperature are desirable.Besides,the oil sorbents also need to be produced environment-friendly.Here we present carbonized melamine-formaldehyde sponges(CMSs)that exhibited superior heating performance and the CMSs could be massively fabricated through a non-polluting pyrolysis process.The conductive CMSs could be heated over 300℃with a low applied voltage of 6.9 V and keep above 250℃for 30 min in the air without obvious damage.Such high heating performance enabled heating up the oil spills with a high rate of 2.65℃·s^(-1) and 14%improvement of oil sorption coefficient compared with the state-of-the-art value.We demonstrated that one joule-heated CMS could continuously and selectively collect viscous oil spills(9,010 mPa·s)690 times its own weight in one hour.The CMSs will be a highly competitive sorbent material for the fast remediation of future crude oil spills.

Hierarchical Silver Indium Tungsten Oxide Mesocrystals with Morphology-, Pressure-, and Temperature-Dependent Luminescence Properties

Highly hierarchical structures of silver indium tungsten oxide(AgIn(WO_(4))_(2))mesocrystals can be rationally fabricated via the microwave-assisted synthesis method by tuning the initial concentrations of the precursors.Photoluminescence spectra of hierarchical AgIn(WO_(4))_(2) mesocrystals were measured to investigate the correlation between the morphology,pressure,and temperature and their luminescence properties.The materials showed interesting white emission when excited by visible light of wavelength 460 nm.AgIn(WO_(4))_(2) materials having different morphologies displayed notable differences in photogenerated emission performance.The emission was strongly correlated with the surface nanostructures of outgrowths,with larger amounts of outgrowths leading to stronger emission intensities.The pressure-and temperature-dependent photoluminescence properties of these materials have also been investigated under hydrostatic pressures up to 16 GPa at room temperature and in the temperature range from 10 to 300 K.

Biomass-based biomimetic-oriented Janus nanoarchitecture for efficient heavy-metal enrichment and interfacial solar water sanitation

Interfacial solar steam generation(ISSG),involving the use of solar energy to evaporate water at the water-to-vapor interface,has presented prospects for the desalination and purification of water due to high energy conversion efficiency and low-cost freshwater generation.Herein,inspired by the aligned nanostructure of plants for efficiently transporting nutrient ions,we optimally design and construct a biomass-based Janus architecture evaporator with an oriented nanostructure for ISSG,using the ice template method,followed by biomimetic mineralization with the resource-abundant and low-cost biomass of the carboxymethyl cellulose and sodium alginate as the raw materials.Taking advantage of the oriented nanostructure allowing efficient transportation of water and coordination capacity of sodium alginate for effective enrichment of heavy-metal ions,the biomass-based Janus architecture shows much lower thermal conductivity and an ultrahigh steam regeneration rate of 2.3 kg m−2 h−1,considerably surpassing those of previously reported oriented biomass-based evaporators.Moreover,the biomass precursor materials are used for this Janus evaporator,guaranteeing minimum impact on the water ecology and environment during the regeneration process of clean drinking water.This study presents an efficient,green,and sustainable pathway for ISSG to effectively achieve heavy-metal-free drinking water.

仅有乙二胺插层的铁硒基超导体(C_2H_8N_2)_xFeSe(英文)

本文采用水热法成功合成了一种新型铁硒基超导体(C_2H_8N_2)_xFeSe,FeSe层间只有乙二胺分子而不包含其他任何金属.碳氢氮元素分析和热重-红外-质谱联合分析的数据都表明层间的乙二胺分子是完整而且独立的.X射线衍射图指出插层化合物是一个正交格子,而以往铁硒基超导体在常温下几乎都是四方格子.磁性测量的数据显示产物在10 K左右有一个大的超导转变,可归结于插层产物(C_2H_8N_2)_xFeSe.此外,在30 K处也观察到一个很小的超导转变,这可能是杂质引起的.

Polymer-mediated mesoscale mineralization

Polymer-controlled mineralization in aqueous solution or in a mixed solvent media, as well as its com-bination with the interface of air-water can lead to the formation of minerals with unique structures and morphologies, which sheds light on the possibility to mimic the detailed structures of the natural min-erals.

荧光碳量子点与贵金属纳米颗粒复合体系构建氰根离子选择性传感器（英文）

以商业蜂花粉为碳源,通过一步水热法制备出氮掺杂的荧光碳量子点作为荧光试剂,并选取金和银纳米颗粒作为光吸收剂,发展了一种基于纳米颗粒内过滤效应以检测氰根离子的荧光方法.金和银纳米颗粒的吸收光谱与碳量子点的激发和发射光谱重叠,满足内过滤效应条件.由于内过滤效应,纳米颗粒可显著猝灭碳量子点的荧光;而当引入氰根离子后,纳米颗粒在氰根离子作用下消蚀变小,对光的吸收变弱,使得碳量子点的荧光逐渐变强,从而实现对氰根离子的选择性检测.

Mo-doped Na3V2（PO4）3@C composites for high stable sodium ion battery cathode

NASlCON-type Na3V2（PO4）3 （NVP） with superior electrochemical perfor- mance has attracted enormous attention with the development of sodium ion batteries. The structural aggregation as well as poor conductivity of NVP hinder its application in high rate perforamance cathode with long stablity. In this paper, Na3V2-xMox（PO4）3@C was successfully prepared through two steps method, including sol-gel and solid state thermal reduction. The optimal doping amount of Mo was defined by experiment. When x was 0.15, the Na3V1.85Mo0.15（PO4）3@C sample has the best cycle performance and rate performance. The discharge capacity of Na3V1.85Mo0.15（PO4）3@C could reach 117.26 mA.h.g-1 at 0.1 C. The discharge capacity retention was found to be 94.5% after 600 cycles at 5 C.

以海绵为载体负载金/二氧化铈纳米线三维材料的制备及其在连续流动系统中原位还原对硝基苯酚(英文)

报道了一种以海绵为模板制备金/二氧化铈纳米线三维材料的普适方法,实现了在连续流动体系中对对硝基苯酚的原位连续还原.该催化系统展现了高的反应活性和稳定性.具有高比表面积的二氧化铈纳米线网络不仅能够使金纳米颗粒稳定分散而防止团聚,而且能够增强二氧化铈纳米线网络与金纳米颗粒之间的协同效应,从而带来高的反应活性和稳定性.低成本原材料和高活性及稳定性的催化剂使得三维海绵-金/二氧化铈纳米线网络结构具有应用于工业生产和其他领域中实现连续催化反应的潜力.

基于π-π/H-键协同作用制备含芘小分子增强高韧性石墨烯纸

轻质高强且具备高韧性的石墨烯组装材料在抗冲击防护领域有着潜在的应用价值.在这项工作中,我们通过在还原氧化石墨烯层间界面交联1-氨基芘AP和1-芘丁酸PB共轭小分子,可以获得具有高导电、高韧性的超强复合石墨烯纸(AP/PB-GPs).结果表明,超过10μm厚度的复合石墨烯纸具有超高的平均韧性(~69.67±15.3 MJ m^(-3)),同时抗拉伸强度接近1 GPa;尤其在抗冲击性能方面,在高速弹道冲击速度下,仍然可以获得优异的比穿透能量吸收值(~0.17 MJ kg^(-1)).详细的界面和结构分析表明,界面增强是由相邻石墨烯层间与共轭分子之间的π-π相互作用和氢键连接共同决定的.尤其是石墨烯纳米片内的孔洞及边缘缺陷更有利于共轭小分子充分的吸附,这必然会使界面结合最大化,在连续高的加载应力下能够有效促进裂纹的偏转和塑性变形.密度泛函理论(DFT)模拟表明,石墨烯纳米片边缘的–COOH极性官能团与AP/PB分子表面的–NH_(2)、–COOH之间的耦合对氢键网络的形成起着关键作用.