Materials
·
2024
·Vol. 17
·期 22
·5655
·
IF 3.1
Tianyu Hao,Jing Shen,Qiaochu Peng,Jie Liu,Wenbin Hu,Cheng Zhong
This study successfully synthesized high-tetragonality barium titanate (BaTiO3) particles with a small particle size by implementing ball milling in the solid-state synthesis of BaTiO3and utilizing nanoscale raw materials. This study also addressed the issues of impurities and uneven particle size distribution that could exist in the synthesized BaTiO3particles. The crystal structure, morphology, and particle size of the synthesized BaTiO3particles have been meticulously analyzed and discussed through the use of techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and the laser particle size analyzer. BaTiO3has been successfully synthesized, exhibiting a uniform particle size with an average diameter of 170 nm and a high tetragonality value of 1.01022. This new solid-state synthesis method provided insights to avoid the impact of “size effects” during the process of electronic device miniaturization.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 91
·期 1
·44-53
·
IF 1.986
Cai Huafei,Jiang Yonggang,Li Liangjun,Feng Junzong,Feng Jian
Abstract Monodispersed silica sol with a small particle size, narrow size distribution, and high conversion was prepared via a modified Stöber method, and an orthogonal test method was used to investigate the influence of TEOS concentration, R (H 2 O/TEOS), ammonia concentration, and reaction temperature on the particle size, size distribution, and conversion of silica sol. It was found that the remarkable factors affecting the particle size from a large to a small order were ammonia concentration, reaction, temperature, and R (H 2 O/TEOS) value; similarly, the remarkable factors affecting the silica sol conversion from a large to a small order were the R (H 2 O/TEOS) value and reaction temperature in decreasing order of influence. None of the factors investigated in this study exhibited a significant effect on the particle size distribution. The optimal synthesis conditions for the preparation of monodispersed silica sol with small particle size and high conversion were as follows: TEOS concentration = 0.4 mol/L; R (H 2 O/TEOS) = 60; ammonia concentration = 0.10 mol/L; reaction temperature = 75 °C. The average particle size of monodispersed silica sol under optimum conditions was 5.25 ± 0.77 nm, and the conversion was 94.05%. Besides, this study also provides a systematic experimental and theoretical basis for the preparation of different particle sizes monodispersed silica sol with high conversion.
Monodispersed silica sol with small particle size, narrow size distribution and high conversion was prepared via a modified Stöber method, and orthogonal test method was used to investigate the influence of TEOS concentration, R (H 2 O/TEOS), ammonia concentration and reaction temperature on the particle size, size distribution and conversion of silica sol. Under the optimum conditions, the monodispersed silica sol with 5.27 ± 0.82 nm average particle size and 94.05% conversion rate was obtained.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jince Zhang,Xiaochen Qi,Yukun Chen,Yixiang Hu,Di Fang,Taiyu Jin,Jun Wang,Dawei Fang
In this study, hydrodynamic cavitation (HC) is used as a novel and simple large-scale preparation technique. Water-soluble CdSeS alloy quantum dots (QDs) were successfully prepared by using Cd(NO 3 ) 2 ·4H 2 O, Na 2 S·9H 2 O and selenium powder as cadmium, sulfur and selenium sources. The effects of cycle time, reaction temperature, inlet pressure and Se/S molar ratio on the morphology, size and optical properties of CdSeS QDs were investigated. The prepared CdSeS QDs were characterized by X-ray diffractometer, X-ray photoelectron spectroscopy, transmission electron microscopy, UV–vis absorption spectra, fluorescence emission spectra and fluorescence attenuation curves. Finally, under the conditions of 12 h cycle time, 3.0 bar inlet pressure, 60 °C reaction temperature and 0.5/0.5 Se/S molar ratio, the ternary alloy CdSeS QDs with 2.62 nm average particle size and 482.62 ns fluorescence lifetime was obtained. Furthermore, a mechanism of preparing CdSeS QDs by using the HC method was proposed to explain the process of CdSeS precipitates conversion to CdSeS QDs. In addition, it is also found that Ag + has a quenching effect on the prepared CdSeS QDs, which means that CdSeS QDs can be used as a fluorescence probe to specifically detect Ag + . This work not only provides a new possibility for large-scale preparation of high-performance QDs but also helps to understand the mechanism of CdSeS QDs as a metal ion selective fluorescence probe.
研究领域:
材料科学
·
化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Jinjian Wei,Mengxin Liu,Xinan Shi,Daocheng Pan
NaYF4:Ce3+,Tb3+ down-conversion nanoparticles with a photoluminescence quantum yield (PLQY) of 54.8% are synthesized by using a ligand-assisted coprecipitation method in this study. The reaction is completed within 1 min at room temperature, and short-chain hexanoic acid and hexylamine serve as the binary ligands, which enable us to synthesize highly luminescent NaYF4:Ce3+,Tb3+ nanoparticles at room temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to characterize the as-prepared nanocrystals. The results reveal that the NaYF4:Ce3+,Tb3+ nanocrystals exhibit excellent dispersion and have a particle size of 2.7 nm. Our NaYF4:Ce3+,Tb3+ nanocrystals possess the advantages of room-temperature preparation, high PLQY, and ultrasmall particle size. These results reveal that the NaYF4:Ce3+,Tb3+ nanocrystals might have a high potential in the applications of lighting, display devices, and bioimaging.
研究领域:
材料科学
·
光学
·
生物成像
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2015
·
IF 3.966
Xiaolong Li,Yin Xiao,Shirong Wang,Xianggao Li
A microemulsion phase transfer method was developed to prepare Y-type titanylphthalocyanine nanocrystals (Y-TiOPc NCs) with an average diameter of 2.3 ± 0.8 nm. The purification and crystal transformation of TiOPc could be achieved in the one-step process by establishing a stable H 2 O/ o -dichlorbenzene microemulsion at high shear rate . The photoelectric characteristics of the ultrasmall Y-TiOPc NCs were evaluated by acting as the photoactive materials in organic photoreceptors , which afforded an impressive photosensitivity of E 1/2 = 0.064 μJ/cm 2 . The dispersion of the Y-TiOPc NCs in a solution of polyvinyl butyral , methylethylketone and cyclohexanone (PVB/MEK/CYC) showed excellent dispersibility (zeta potential: –50.0 mV) at least 60 days and suffered no photoelectric penalty. The excellent solvent-stabilized dispersibility mainly relied on electrostatic repulsion force resulting from the high charge-mass ratio due to ultrasmall particle size.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Xiaoyang Wang,Ziqi Fu,Ziyi Luo,Weidi Liu,Jia Ding,Jianrong Zeng,Yanan Chen,Wenbin Hu
High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer, which enhance mass transport and maintain the balance of water and heat. Unfortunately, as the loading increases, the agglomeration and growth of Pt nanoparticles (NPs) occur, causing unsatisfactory performance. Here, we present an efficient method for preparing of highly dispersed and small-sized Pt/C catalysts with Pt loadings varying from 39.01 wt% to 66.48 wt% through the high-temperature shock technique. The high density and ultrafine (~2.5 nm) Pt NPs are successfully anchored onto Vulcan XC-72R carbon black without the use of additional capping agents or surfactants. The modified carbon supports enhance the affinity for Pt precursors, contributing to loading efficiencies of 95% or more, while also providing abundant sites for the nucleation and fixation of Pt NPs, thus preventing agglomeration. In the context of the hydrogen evolution reaction in acidic media, the as-synthesized high-loading Pt/C catalysts show remarkable activity and stability, outperforming the state-of-the-art commercial Pt/C. This is mainly because the combined effects of ultrasmall and uniform Pt NPs, optimized electronic structure of Pt site, superhydrophilicity and effective anchoring of Pt NPs. The polymer electrolyte membrane electrolyzer integrated with Pt60/OX72R and commercial IrO 2 reaches 1 A cm –2 at 1.77 V and operates stably for 120 hours with a negligible voltage decay. This new strategy is fast, scalable and cost-effective for large-scale production of metal-supported catalysts, especially for the high-loading ones.
研究领域:
催化化学
·
纳米技术
·
材料科学
·
电化学
·
能量转换
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Yanfu Ma,Guangyue Xu,Hao Wang,Yingxiong Wang,Ying Zhang,Yao Fu
In this study, rare earth (RE) metal doped ZrO2 was prepared by a surfactant-assisted coprecipitation/hydrothermal crystallization method and used to load Co as catalyst for the hydrogenation of aromatic carbonyl compounds in water. Furfural was hydrogenated to furfural alcohol in water with up to 95 mol % yield over Co/ZrLa0.2Ox at 40 °C, 2 MPa H2 in 10 h. The doping of rare earth metal oxide has three advantages: (I) it promotes the ZrO2 to reach a small-sized, stable, and high-activity tetragonal phase zirconia and thus lead to a high specific surface area for metal loading; (II) it interacts with Co to reach an ultrasmall average particle size of 1.1 nm; and (III) it modifies the ZrO2 surface to increase the amount of acidic sites for the adsorption of carbonyl feedstock. The adsorption experiment indicated a tight interaction between not only the carrier and C═O bond but also the Co clusters and C═O bond, which were of benefit for the hydrogenation of carbonyl groups. The surfactant addition during the carrier preparation improves the strong metal–support interactions (SMSI) to promote Co dispersion and stability. Various rare earth metals including La, Pr, Nd, and Ce could modify ZrO2 with a similar mechanism. The as-prepared Co catalyst could also catalyze the selective hydrogenation of various aromatic aldehydes and ketones (such as 5-hydroxymethyl furfural, benzaldehyde, and acetophenone) in water, and 100% yield to corresponding alcohols was achieved. The catalyst remained stable and showed little deactivation during the recycling tests. This study not only presented a high-efficient, low-cost, and stable catalyst for the selective hydrogenation of various aromatic aldehydes and ketones but also give rise to an understanding of rare earth metal oxide doped ZrO2 supported nano Co ternary catalysts.
研究领域:
催化
·
材料科学
·
化学工程
·
绿色化学
·
纳米技术
✓ 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）