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Si_2Sb_2Te_5 phase change material studied by an atomic force microscope nano-tip

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Journal of Semiconductors 2009年第6期30卷 34-37页

作者：刘彦伯张挺钮晓鸣宋志棠闵国全张静周伟民万永中张剑平李小丽封松林 Laboratory of Nano-Technology Shanghai Nanotechnology Promotion Center State Key Laboratory of Functional Materials for Informatics Laboratory of Nanotechnology Shanghai Institute of Microsystemand Information Technology Chinese Academy of Sciences

The Si2Sb2Te5 phase change material has been studied by applying a nano-tip（30 nm in diameter） on an atomic force microscopy *** switching from a high resistance state to a low resistance state has been achieved,with a resistance change of about 1000 *** a typical I-V curve,the current increases significantly after the voltage exceeds～4.3 *** phase transformation of a Si2Sb2Te5 film was studied in situ by means of in situ X-ray diffraction and temperature dependent resistance *** thermal stability of Si2Sb2Te5 and Ge2Sb2Te5 was characterized and compared as well.

关键词： phase change electrical probe storage Si2Sb2Te5

Optoelectronic and electrochemical behaviour of γ-CuI thin films prepared by solid iodination process

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Progress in Natural Science:Materials International 2019年第5期29卷 533-540页

作者： Karthik Kumar Chinnakutti Vengatesh Panneerselvam Durai Govindarajan Ajith kumar Soman Kuppusami Parasuraman Shyju Thankaraj Salammal Centre of Excellence for Energy Research Sathyabama Institute of Science and Technology Centre for Nanoscience and nanotechnology Sathyabama Institute of Science and Technology

A simple and efficient solid iodination method has been proposed for the fabrication of p-type γ-CuI thin *** structural,morphological,optical,electrical and electrochemical properties have been investigated in order to serve as an effective hole-transporting layer in solid-state solar *** fabricated films exhibited p-type conductivity with resistivity of 7.0×10;Ωcm,the hole concentration of ～1.13×10;cm;and the mobility of 18.34 cm;V;s;.The cyclic voltammetry result shows a maximum specific capacitance of 43 mF/cm;at a scan rate of 10 mV/*** cyclic stability and capacitance retention were found to be 99.7%.These findings demonstrate that γ-CuI film can be a potential candidate for multiple applications,such as a hole transporting material for solid-state solar cells and electrochemical supercapacitor.

关键词： Copper iodide Solid iodination Hole mobility Cyclic voltammetry

Confined growth of ZIF-8 in dendritic mesoporous organosilica nanoparticles as bioregulators for enhanced mRNA delivery in vivo

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National Science Review 2021年第8期8卷 198-207页

作者： Yue Wang Hao Song Chao Liu Ye Zhang Yueqi Kong Jie Tang Yannan Yang Chengzhong Yu Australian institute for Bioengineering and nanotechnology The University of Queensland School of Chemistry and Molecular Engineering East China Normal University

Zeolitic imidazolate framework-8(ZIF-8) and its composites have diverse applications. However,ZIF-8-based nanocomposites are mainly used as carriers in biomolecular delivery, with the functions of metal ions and ligands rarely used to modulate the biofunctions. In this work, dendritic mesoporous organosilica nanoparticles(DMONs) with tetrasulfide bond were used to confine ZIF-8 growth partially inside mesopores as a novel nanocomposite for m RNA delivery. Each component in the resultant DMONs-ZIF-8 contributed to m RNA delivery applications, including high loading benefitting from positively charged ZIF-8 and large mesopores of DMONs, endosomal escape promoted by the imidazole ring of ZIF-8, and long-term glutathione depletion mediated by both zinc ions and tetrasulfide *** together, DMONs-ZIF-8 demonstrated enhanced m RNA translation and better transfection efficiency than commercial products and toxic polymer-modified DMONs in vitro and in vivo.

关键词： mesoporous organosilica nanoparticles metal-organic framework mRNA transfection cellular delivery bioregulator

Microstructural evolution of Al-20Si-5Fe alloy during rapid solidification and hot consolidation

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Rare Metals 2009年第6期28卷 639-645页

作者： M.Rajabi M.Vahidi A.Simchi P.Davami Department of Materials Science and Engineering Sharif University of Technology institute for Nanoscience and nanotechnology (INST) Sharif University of Technology

Al-20Si-5Fe melt was rapidly solidified into particles and ribbons and then consolidated to near full density by hot pressing at 400℃/250 MPa/1 h. According to the eutectic-growth and dendritic-growth velocity models, the solidification front velocity and the amount of undercooling were estimated for the particles with different sizes. Values of 0.43-1.2 cm/s and 15-28 K were obtained. The secondary dendrite arm spacing revealed a cooling rate of 6 × 10^5 K/s for the particles with an average size of 20 μm. Solidification models for the ribbons yielded a cooling rate of 5 × 10^7 K/s. As a result of the higher cooling rate, the melt-spun ribbons exhibited considerable microstructural refinement and modification. The size of the primary silicon decreased from approximately 1μm to 30 nm while the formation of iron-containing intermetallic compounds was suppressed. Supersaturation of the aluminum matrix in an amount of-7 at.% Si was noticed from the XRD patterns During the hot consolidation process, coarsening of the primary silicon particles and precipitation of β-Al5FeSi phase were observed. Evaluation of the compressive strength and hardness of the alloy indicated an improvement in mechanical properties due to the microstructural modification.

关键词： Al-Si-Fe alloy rapid solidification cooling rate microstructure mechanical properties

Fermi-level-tuned MOF-derived N-ZnO@NC for photocatalysis:A key role of pyridine-N-Zn bond

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Journal of Materials Science & Technology 2022年第17期112卷 68-76页

作者： Zheao Huang Qiancheng Zhou Jieming Wang Ying Yu institute of Nanoscience and nanotechnology College of Physical Science and TechnologyCentral China Normal UniversityWuhan 430079China

For photocatalytic materials,the composites formed by metal oxides and heteroatom-doped carbon have outstanding *** them,metal-organic framework(MOF)derived composites,usually composed of metal oxide and nitrogen-doped carbon,is not only simple to prepare,but also have far-exceeding catalytic performance than homogenous ***,the relationship between the structure and performance in the photocatalytic system is still not ***,we explored the tunable nitrogen configurations in sample N-ZnO@NC by controlling the thermal conversion of ***,through exsitu and in-situ XPS characterization,it is found that the ZnO and nitrogen-doped carbon in N-ZnO@NC are connected by C-N-Zn bond,which enhances charge separation efficiency and becomes the origin of superior photocatalytic *** calculations further reveal the influence of different Zn-bonding nitrogen configurations on the adjusting of Fermi level and electron *** study exhibits that the pyridine-N configuration in MOF-derived material is the main contributor for the improved performance and tunes Fermi level more appropriately than the pyrrolic-N,which can hold the key for future design of next-generation photocatalysts.

关键词： MOF-derived material Fermi level Pyridine-N-Zn DFT calculations Photocatalysis

Performance improvement of hybrid polymer membranes for wastewater treatment by introduction of micro reaction locations

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Progress in Natural Science:Materials International 2018年第2期28卷 148-159页

作者： Ying Wang Ming Yong Song Wei Yuqing Zhang Wei Liu Zhiping Xu School of Chemical Engineering and Technology Tianjin University Australian institute for Bioengineering and nanotechnology University of Queensland

This article reviews the progresses on polymer membranes embedded with novel inorganic nanomaterials to provide micro reaction locations(MRLs) in the polymer matrices for wastewater treatment. Ultrafiltration(UF)membranes, especially polyvinylidene fluoride(PVDF) and polysulfone(PSF) membranes, are broadly applied in wastewater treatment. The strategy of embedding functional nanomaterials into the polymer matrices has been extensively investigated to enhance the integrated properties of polymer membrane. Nevertheless, the performance enhancement just comes from physical interactions between nanomaterials and wastes, while the chemical interactions are not involved, thus limiting further improvements. In order to further enhance the integrated properties of polymer membranes, functional inorganic nanomaterials that can chemically react with the wastes are proposed and embedded into the polymer membranes to form many MRLs. In this paper, the strategies for embedding functional nanomaterials such as sulfated TiO2deposited SiO2nanotubes, solid superacid porous ZrO2shell/void/TiO2core particles and porous YxFeyZr1-x-yO2coated TiO2solid superacid nanoparticles in polymer membranes were presented and the enhancement effect of MRLs on their integrated properties for wastewater treatments was discussed. Therefore, polymer membranes embedded with functional inorganic nanomaterials with MRLs are potentially applied in various wastewater treatments.

关键词： Nanomaterials Micro reaction locations Polymer membrane Ultrafiltration Wastewater treatment

Highly efficient nitrogen fixation over S-scheme heterojunction photocatalysts with enhanced active hydrogen supply

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National Science Review 2024年第5期11卷 315-325页

作者： Tong Bao Yamin Xi Chaoqi Zhang Peiyang Du Yitong Xiang Jiaxin Li Ling Yuan Chengzhong Yu Chao Liu School of Chemistry and Molecular Engineering East China Normal University Australian institute for Bioengineering and nanotechnology The University of Queensland

Photocatalytic N2fixation is a promising strategy for ammonia（NH3） synthesis;however,it suffers from relatively low ammonia yield due to the difficulty in the design of photocatalysts with both high charge transfer efficiency and desirable N2adsorption/activation ***,an S-scheme CoSx/ZnS heterojunction with dual active sites is designed as an efficient N2fixation *** CoSx/ZnS heterojunction exhibits a unique pocket-like nanostructure with small ZnS nanocrystals adhered on a single-hole CoSxhollow *** the heterojunction,the ele ctronic interaction between ZnS and CoSxcreates electron-deficient Zn sites with enhanced N2chemisorption and electron-sufficient Co sites with active hydrogen supply for N2hydrogenation,cooperatively reducing the energy barrier for *** combination with the promoted photogenerated electron-hole separation of the S-scheme heterojunction and facilitated mass transfer by the pocket-like nanostructure,an excellent N2fixation performance with a high NH3yield of 1175.37 μmol g-1h-1is *** study provides new insights into the design of hetero junction photocatalysts for N2fixation.

关键词： photocatalysis nitrogen fixation S-scheme heterojunction active hydrogen ammonia

Fouling of WO3 nanoparticle-incorporated PSf membranes in ultrafiltration of landfill leachate and dairy a combined wastewaters： An investigation using model

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Chinese Journal of Chemical Engineering 2017年第6期25卷 741-751页

作者： Majid Peyravi Mohsen Jahanshahi Soodabeh Khalili Nanoenvironment Research Group Nanotechnology Institute Faculty of Chemical Engineering Babol Noshirvani University of Technolog~ Babol lran

As fouling has always been a major drawback of membrane technology, qualitative and quantitative understanding of membrane fouling mechanisms therefore becomes vital in order to help push membrane separation technologies forward. In this study, firstly, self-cleaning Polysulfone(PSf) membranes were synthesized by incorporation of WO_3nanoparticles(0–2 wt%) and subsequent UV irradiation for efficient ultrafiltration(UF)of landfill leachate and dairy wastewater. The membrane surface properties were characterized by scanning electron microscopy(SEM) and contact angle analysis. It was found that UV-irradiated membranes exhibited higher percent COD removals due to the hydrophilicity and photocatalytic properties of nano-WO_3. Subsequently, in order to analyze the fouling behavior of the membranes, a set of experimental data from cross-flow ultrafiltration of municipal landfill leachate and industrial dairy wastewater at 25 °C was obtained. A new model of membrane fouling was proposed based on a resistance in series concept and was fitted well with all experimental data *** all relative errors of prediction provided by the proposed model were less than 2.5%. In addition, it was revealed that this newly-developed model exhibited smooth transition between the common successive twostep pore blockage-cake filtration phenomena and thus eliminates the need to use separate equations for different mechanisms.

关键词： Fouling model Leachate wastewater Ultrafiltration Whey wastewater Chemical oxygen demand

Surface modification by ligand growth strategy for dense copper bismuth film as photocathode to enhance hydrogen production activity

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Frontiers in Energy 2024年第1期18卷 89-100页

作者： Zhouzhou WANG Qingwei WU Jieming WANG Ying YU institute of Nanoscience and nanotechnology College of Physical Science and TechnologyCentral China Normal UniversityWuhan 430079China

Hydrogen production from photoelectrochemical(PEC)water splitting has been regarded as a promising way to utilize renewable and endless solar ***,semiconductor film grown on photoelectrode suffers from numerous challenges,leading to the poor PEC ***,a straightforward sol-gel method with the ligand-induced growth strategy was employed to obtain dense and homogeneous copper bismuthate photocathodes for PEC hydrogen evolution *** various characterizations,it was found that the nucleation and surface growth of CuBi_(2)O_(4)layer induced by 2-methoxyethanol ligand(2-CuBi_(2)O_(4))demonstrated a decent crystallinity and coverage,as well as a large grain size and a low oxygen vacancy concentration,leading to the good ability of light absorption and carrier ***,under simulated sunlight irradiation(AM1.5G,100 mW/cm^(2)),the 2-CuBi_(2)O_(4)photocathode achieved an enhanced photocurrent density of−1.34 mA·cm^(−2)at 0.4 V versus the reversible hydrogen electrode and a promising applied bias photon-to-current efficiency of 0.586%.This surface modification by ligand growth strategy will shed light on the future design of advanced photoelectrodes for PEC water splitting.

关键词： copper bismuthate photocathode ligand growth strategy dense film PEC