CRYSTENGCOMM
·
2017
·Vol. 19
·期 26
·3600-3606
·
IF 3.474
Suli Wu,Xiaoqian Sun,Zhipeng Meng,Shufen Zhang
Doping, incorporating appropriate and functional atoms or ions into host lattices of colloid nanoparticles, is an important approach to modifying the shapes and sizes of nanoparticles and endowing them with new and useful properties. Herein, we demonstrate a “core–shell” synthetic strategy to control the shape of core–shell structured NaGdF4 upconversion nanoparticles (UCNPs) by introducing an impurity dopant in the core region. We introduced Cr3+ ions in the core region of NaGdF4 to synthesize “Jasminum sambac flower” shaped non-classic core–shell NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ UCNPs. First of all, the effect of doping concentration on the shape of NaGdF4 core was investigated. Then, the core–shell strategy was applied to obtain a shape-controlled hierarchical nanostructure, and the effects of Cr3+ concentration on the phases, shapes and sizes of the products were investigated in detail. TEM images indicate that NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ nanocrystals with Cr3+ concentration of 40–50% show highly uniform “Jasminum sambac flower” shaped structures. TEM images and XRD patterns of NaGdF4:Cr3+@NaGdF4:Yb3+,Tm3+ at different reaction times indicate that, initially, the flower shaped products are cubic phase and the size of the flowers is about 50 nm; with an increase of the reaction time, the cubic phase nanocrystals discompose to small ones and then transform to a bigger hexagonal phase “Jasminum sambac flower”. This “core/shell” doping strategy presents a general route to achieving controlled morphology in lanthanide-doped nanocrystal systems.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Micro & Nano Letters
·
2018
·Vol. 13
·期 10
·1443-1446
·
IF 0.841
Jin Li,Ben Ze Wu,Zhen Xiang Zhou
γ-Bi 2 O 3 powders were prepared from [Bi(NO 3 ) 3 ·5H 2 O] and NaOH through low-temperature liquid phase method at <90°C. This process featured low cost, simplicity and a normal pressure. Bismuth oxides were synthesised in large quantities in water systems. Morphology, structure and optical properties were characterised by X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and ultraviolet visible absorption spectrophotometry (UV–Vis). The SEM indicated that tetrahedral Bi 2 O 3 with the edge length of 1–5 μm was formed. The FTIR spectra show a chemical bond of Bi–O existed. Bi 2 O 3 presents the photo absorption properties from UV light region to visible light and the band gap of the Bi 2 O 3 is 3.0 eV.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2016
·
IF 1.207
Lei Yang,Yangyang Zhang,Hua Li,Hezhou Liu
Metallic bismuth crystal is one important and interesting semimetal that has attracted great attention owing to its unique thermal and electrical properties. Herein, we report a facile, green, cost-effective and sustainable solvothermal process using ethanol, glycol, isopropanol, phenylcarbinol as solvent and commercial Bi 2 O 3 as the starting material to produce high-purity metallic Bi with tunable morphologies on large scale. It is found that all alcohols are capable of reducing Bi 2 O 3 to Bi and the reducibility of glycol is proved to be the strongest. The highest purity of the resultant Bi is calculated to be 99.74%. What's more, the morphology of final Bi particles is controllable by adding various types and concentrations of additives. As a consequence, our work lays the root for the large scale solvothermal production of high-purity Bi particles with various regular morphologies.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2017
·Vol. 4
·期 4
·045006
·
IF 1.068
Hongtao Cui,Li Wang,Min Shi,Yanhong Li
In this work, lepidocrocite (γ-FeOOH) nanobundles were prepared by a facile NH4F assisted epoxide precipitation route. The reactions between epoxide and [Fe(H2O)6]2+ promoted the hydrolysis and condensation of [Fe(H2O)6]2+, resulting in the formation of iron oxyhydroxide. After calcination of γ-FeOOH nanobundles at 400 °C, the produced α-Fe2O3 still kept the bundle morphology. Due to the unique chemistry of epoxide, the morphology and phase of iron oxide polymorph nanoparticles (goethite, akaganeite, lepidocrocite, magnetite) were well-controlled through controlling reaction conditions such as Fe2+ concentration, NH4F additive and reaction temperature. It is particularly interesting that NH4F working as phase controlling agent is able to control the phase development of iron oxyhydroxides. This phase control effect of NH4F is attributed to the promoted reaction rate of epoxide originating from the higher electronegativity of fluoride ions than chloride ions. Based on the results in this work and our other preliminary works, it is considered that this route can be used as a general strategy for controlling the morphology and phase of transition element compounds.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 46
·8944-8952
·
IF 3.849
Jun Yang,Jingjing Cao,Dingyi Shen,Jie Xiong,Jianfeng Tang,Shanshan Hu
Well-crystallized and uniform ScPO4·2H2O and ScPO4·2H2O:Ln3+ (Ln = Ce, Eu, Tb, Lu) nano/micro-crystals with multiform morphologies, such as sphere, hexagonal plate, diamond, four-angle star, butterfly-shaped and cuboid, have been successfully synthesized by a facile hydrothermal route without any surfactant molecules. XRD, FE-SEM, TEM, PL and kinetic decay were used to characterize the as-prepared products. The size and morphology of ScPO4·2H2O can be determined by the pH value, reaction time, reaction temperature, additive and doping of lanthanide ions. In particular, Ln3+ doping not only has a crucial role in the morphology of ScPO4·2H2O, but also affects its luminescence properties. The ScPO4·2H2O:Tb3+ and ScPO4·2H2O:Ce3+ samples display intense green and blue emissions, respectively. More importantly, the luminescence properties are closely related to morphologies and crystallinity. It can be found that the ScPO4·2H2O:Tb3+ sample with a hexagonal plate-like morphology possesses much higher emission intensity than those with other morphologies because of its larger anisotropic geometry. ScPO4:Ln3+ crystals will become promising candidates for a variety of applications in down/up-conversion luminescence, magnets, lasers, and bio-labeling.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 15
·8843-8858
·
IF 4.21
Jiang Mengting,Zhang Yakang,Chen Jingwen,Liang Qian,Xu Song,Yao Chao,Zhou Man,Li Zhongyu
A series of morphology-controlled BiOBr nano/macrostructures was successfully synthesized via a novel biomass-route derived from bacterial cellulose (BC). In the BiOBr/BC system compared with pure BiOBr, the three-dimensional BC scaffolds not only effectively prevented the aggregation of BiOBr units by pore confinement, but also strengthened the controllability of BiOBr size with the help of abundant anchoring sites provided by cross-linked BC fibers. By associating the results of characterizations and the photodegradation of RhB dye, the relationship between morphology and photocatalytic activity of BiOBr/BC was investigated. In addition, a possible mechanism for the enhanced photocatalytic activity of the optimized BiOBr/BC has been discussed. This biomass-derived route provides a platform for further design of bismuth-based composite photocatalysts with potential advantages of being anti-aggregation, highly-dispersed, easily recovered and having enhanced catalytic performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Yaning Gao,Yin Wang,Hui Sun
The control of the morphology and nanostructure of soft nanomaterials self-assembled from amphiphilic polymers has attracted significant attention. In this study, various nanostructures including bowl-shaped nanoparticles with controlled openings, round Yuanbao-shaped assemblies, nanowires and butterfly shaped twin nanosheets are formed by manipulating the self-assembly pathway of an amphiphilic homopolymer. The amphiphilic (poly( N -(2,2′-bipyridyl-4-acrylamide), PBPyAA) with bipyridine pendants is designed and synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization, which can self-assemble into bowl-shaped nanoparticles with controlled openings by solvent switch method at different initial concentrations. In addition, core–shell nanostructures are obtained taking advantage of the coordination between bipyridine and Fe 2+ . Upon annealing in ethanol, butterfly shaped twin nanosheets with thickness of about 10 nm are formed by controlling the cooling rate, while round Yuanbao-shaped assemblies are formed by naturally cooling. Revealing into the formation mechanism of the butterfly shaped twin nanosheets, a fusion induced assembly process of nanowires is observed. Overall, various nanostructures are obtained by manipulating the self-assembly pathways of a bipyridine containing amphiphilic homopolymer.
研究领域:
材料科学
·
高分子化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2025
·Vol. 15
·期 5
·451
·
IF 2.4
Chunli Cai,Qian Wang,Changsheng Yin,Xuhuan Li,Rong Yang,Xiaodong Shen,Wenbo Xin
AgCl microcrystals are used in visible light photocatalysis. However, their properties depend strongly on the morphology of the crystals and the degree of exposure of the crystal planes. Despite extensive research conducted on the synthesis of AgCl microcrystals, the majority of existing studies have focused on the stable growth of crystals. The role of Cl−ions concentration as a key factor controlling the microcrystals morphology has not been fully explored, which limits the precise tuning of the morphology of AgCl microcrystals. In this study, AgCl microcrystals with controllable morphology are successfully synthesized by a facile solvothermal method. During the preparation process, ethylene glycol (EG) is utilized as a solvent, while polyvinylpyrrolidone (PVP) is employed as a surfactant. We systematically investigate the etching mechanism of AgCl microcrystals by analyzing the effect of sodium chloride (NaCl) concentration on their morphology. This investigation involves the integration of diverse characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and geometrical struc-ture analysis. The results demonstrate that Cl−functions as both a surfactant, thereby promoting the nucleation of cubic microcrystals, and as an etchant, selectively etching the crystal surface. The order of selective etching on the crystal surface follows (100) planes > (110) planes > (111) planes. Based on this new mechanism, AgCl microcrystals with various morphologies, such as cube, octopod and dendrite, are successfully prepared, which provides a new idea for the precise design of noble metal halide microcrystals.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
e-Journal of Surface Science and Nanotechnology
·
2012
·
IF 0
L. Z. Pei,Y. Q. Pei,Y. K. Xie,Z. Y. Cai
Calcium sulfate and calcium vanadate nanostructures have been synthesized by a hydrothermal route using calcium sulfate and sodium vanadate as the raw materials. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectrum. XRD and SEM observation show that the products are composed of calcium sulfate nanosheets with orhorhombic CaSO4 phase and calcium vanadate nanorods with tetragonal CaV4O9 phase. The size and morphology of the products can be adjusted by controlling the hydrothermal conditions and raw materials. The size of calcium sulfate nanosheets and calcium vanadate nanorods increases obviously with increasing the hydrothermal temperature and reaction time. The formation process of the calcium sulfate and calcium vanadate nanostructures is also discussed. [DOI: 10.1380/ejssnt.2012.585]
研究领域:
无机化学
·
材料科学
·
纳米技术
·
固体化学
·
功能材料
✓ 已验证
DOI
CHEMICAL PHYSICS LETTERS
·
2016
·
IF 1.86
Jiangyun Dai,Guoying Feng,Jiajia Yin,Chao Yang,Xianheng Yang,Hua Zhang,Hong Zhang,Shouhuan Zhou
NaGdF 4 nanocrystals with controlled shapes were synthesized in an ethylene glycol/deionized water hydrothermal reaction system. Through adjusting the solvent composition, the nanocrystals with nanosphere-, nanotube-, and nanorod-like morphology have been selectively synthesized. The change in the nucleation speed, the growth rates in different crystallographic direction and the aggregation driving forces induced different morphologies of the resulting nanocrystals. A possible mechanism of shape evolution depending on solvent composition was proposed. Photoluminescence spectra of NaGdF 4 :Nd 3+ nanocrystals exhibited characteristic emission of Nd 3+ using an excitation wavelength of 794 nm. Moreover, the nanotube-like nanocrystals exhibited the strongest fluorescence intensity and longest fluorescence decay time.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FLUORINE CHEMISTRY
·
2015
·
IF 1.948
Songxia Yu,Ruijun Cao,Jun Li,Lingjie Meng
NdF 3 nanoflakes and hexagonal NaNdF 4 nanorods were successfully prepared in a facile manner by the one-pot microwave-assisted hydrothermal reaction of Nd(NO 3 ) 3 ·6H 2 O and NaF within 3 h at pH = 1 and pH = 3–10, respectively. Ethylenediaminetetraacetic acid disodium salt (C 10 H 14 N 2 O 8 Na 2 ·2H 2 O, EDTA–2Na) was used as the morphology-controlling agent. The size, morphology, and crystallinity of the resulting nanocrystals can be easily tuned by adjusting the reaction temperature and time. The as-prepared NdF 3 nanoflakes and NaNdF 4 hexagonal prisms were characterized by X-ray diffraction and scanning electron microscope. All nanocrystals exhibited a typical hexagonal phase, and their crystallization improved with increasing reaction temperature and reaction time. A strong emission spectrum was observed at approximately 850–900, 1060, and 1330 nm for both NdF 3 nanoflakes and NaNdF 4 nanorods under a laser excitation of 354 nm, indicating that Nd 3+ exhibits high luminescence in these two nanocrystals.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
·
2019
·Vol. 42
·期 1
·1-5
·
IF 1.264
Zhou Wei,Xie Qian,Li Junjie,Zhengwei Cao,Peng Feng
A simple and economic \(\hbox {CO}_{{2}}\) bubbling crystallization reactor for preparation of strontium carbonate \((\hbox {SrCO}_{3})\) was designed. Through monitoring pH and conductivity, hollow \(\hbox {SrCO}_{{3}}\) fibres without any morphology control agents were successfully obtained. The effects of temperature and \(\hbox {CO}_{{2}}\) flow rate on the morphology of \(\hbox {SrCO}_{{3}}\) were analysed. This study presents a new method for carbonate crystal control and growth.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）