CRYSTENGCOMM
·
2020
·Vol. 22
·期 28
·4790-4796
·
IF 3.117
Kaixuan Zhao,Zhijie Yang,Huiying Wei,Jinxin Guo,Yanzhao Yang,Jingjing Wei
The prevalent synthesis of colloidal metal oxide nanocrystals relies on the synthesis of various precursors, such as organometallic compounds, which are usually sensitive to moisture or oxygen and generally expensive. Based on the economic efficiency, the costs of the starting materials and synthetic process should be addressed. Herein, a general simple synthetic procedure from inexpensive and nontoxic precursors is developed. Under optimized reaction conditions, MnO nanocrystals are synthesized with commercially purchased bulk manganese oxides as starting materials, such as MnO, MnO2, and Mn3O4. The size and morphologies of nanoparticles are modulated by tuning the types and dosage of coating agents. Moreover, this synthetic strategy is further extended to other nanoparticles including Fe3O4 nanocrystals and FeMnOx nanocrystals. Furthermore, Re doped MnO nanocrystals exhibiting fluorescence properties have been synthesized with this method, which endows the fluorescence properties to these oxide nanocrystals.
研究领域:
材料科学
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纳米技术
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 20
·5506-5513
·
IF 5.976
Meng Li,Xiao Zhang,Katarzyna Matras-Postolek,Hsueh-Shih Chen,Ping Yang
Fast and efficient ion-exchange reactions endow CsPbX3 nanocrystals (NCs) with superior photoluminescence (PL) properties. In this study, SnX2 (X = I, Cl) was used as a Sn precursor to conduct the cation exchange reaction, which was promoted by anion exchange between the parent CsPbBr3 NCs and the guest X in SnX2. The anion-driven cation exchange reaction occurred efficiently (10 min). CsSnI3 NCs were created by ion-exchange reactions between CsPbBr3 NCs and the SnI2 precursor. The CsSnI3 NCs retained the initial morphology of CsPbBr3 NCs and revealed a high PL efficiency (59%) and prolonged PL lifetime. In contrast, the exchange reaction of Sn2+ ions in CsPbBr3 NCs did not occur in a short time using SnBr2 as a precursor. After the cation exchange reaction, the 4f peaks of Pb ions in X-ray photoelectron spectroscopy spectra shifted to low binding energies as compared to those of the parent CsPbX3 NCs. This is ascribed to the increase in the number of Pb–oleate (Pb–OA) species. Contrary to the hot-injection method used to synthesize CsSnI3 NCs, the kinetically controlled ion exchange reactions lead to the synthesis of CsSnI3 NCs with a high structural stability. Thus, an anion-exchange-promoted cation exchange reaction is a particularly efficient versatile tool to dope Sn2+ into CsPbX3 NCs.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Huan Tian,Yi Liu,Feng-Lei Jiang
Perovskite nanocrystals attract growing interest owing to their unique optoelectronic properties. However, their chemical stability is relatively poor due to their ionic nature. In this work, we found that inorganic cations (e.g., Cs+) and ligands (e.g., didodecyldimethylammonium bromide, DDAB), used in the synthesis of CsPbBr3 nanocrystals (NCs) at ambient temperature, quickly converted CsPbBr3 NCs to Cs4PbBr6 NCs during the synthesis or postsynthetic treatment. These cations (Cs+, DDA+) were involved in both the chemical composition and dissociation of CsPbBr3 NCs. Nevertheless, DDA+ induced the generation of an impurity in addition to Cs4PbBr6 NCs due to its different nature from that of Cs+. The transformation process was observed by optical spectroscopy and transmission electron microscopy. The reverse transformation of Cs4PbBr6 NCs to CsPbBr3 NCs can be carried out completely by adding sufficient PbBr2 into Cs4PbBr6 NCs. Therefore, the forward and backward reactions were driven by Cs+ and Pb2+. With additional DDAB for passivation during the reverse transformation, the resulting product possessed a better photoluminescence quantum yield (PLQY, ∼90%) compared with that without the involvement of DDAB (∼69%). By considering the Cs4PbBr6 NCs as the Cs source, the reverse transformation can be analogized to the synthesis of CsPbBr3 NCs, providing a possible strategy for synthesizing luminescent perovskite NCs at room temperature with theoretical stoichiometry.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2013
·Vol. 24
·期 35
·355602
·
IF 3.842
Aiwei Tang,Yu Wang,Haihang Ye,Chao Zhou,Chunhe Yang,Xu Li,Hongshang Peng,Fujun Zhang,Yanbing Hou,Feng Teng
A one-step colloidal process has been adopted to prepare silver (Ag) and silver sulfide (Ag2S) nanocrystals, thus avoiding presynthesis of an organometallic precursor and the injection of a toxic phosphine agent. During the reaction, a layered intermediate compound is first formed, which then acts as a precursor, decomposing into the nanocrystals. The composition of the as-obtained products can be controlled by selective cleavage of S–C bonds or Ag–S bonds. Pure Ag2S nanocrystals can be obtained by directly heating silver acetate (Ag(OAc)) and n-dodecanethiol (DDT) at 200 ° C without any surfactant, and pure Ag nanocrystals can be synthesized successfully if the reaction temperature is reduced to 190 ° C and the amount of DDT is decreased to 1 ml in the presence of a non-coordinating organic solvent (1-octadecene, ODE). Otherwise, the mixture of Ag and Ag2S is obtained by directly heating Ag(OAc) in DDT by increasing the reaction temperature or in a mixture of DDT and ODE at 200 ° C. The formation mechanism has been discussed in detail in terms of selective S–C and Ag–S bond dissociation due to the nucleophilic attack of DDT and the lower bonding energy of Ag–S. Interestingly, some products can easily self-assemble into two- or three-dimensional (2D or 3D) highly ordered superlattice structures on a copper grid without any additional steps. The excess DDT plays a key role in the superlattice structure due to the bundling and interdigitation of the thiolate molecules adsorbed on the as-obtained nanocrystals.
研究领域:
材料科学
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纳米技术
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化学合成
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Hajo Yagoub,Liping Zhu,Mahmoud H.M.A. Shibraen,Ali A. Altam,Dafaalla M.D. Babiker,Kiran Rehan,Vincent Mukwaya,Jian Xu,Shuguang Yang
The treatment of oily wastewater is a global challenge owing to its diverse repercussions on environment and human life. The nanoporous complex membrane consisted of cellulose nanocrystals (CNC), chitin nanocrystals (ChiNC) and chitosan (CH) is fabricated on top of the poly (ethylene terephthalate) (PET) nonwoven fabric via a vacuum-assisted filtration method. The interactions among CNC, ChiNC and CH cause the formation of the membrane which shows underoil superhydrophobic property. The CH is demonstrated to play a key role in contributing to the hydrophobicity of membrane. Without any further treatment, the CNC/ChiNC/CH membrane is capable to separate water from water-in-oil emulsion with a high rejection. The separation performance is affected by the thickness of the prepared membrane which directly relates to the concentrations of the complex solutions. Such polysaccharide-based complex membranes with facile fabrication and low cost are promising for use in the field of oil/water separation.
研究领域:
材料科学
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环境科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science China-Materials
·
2015
·Vol. 58
·期 9
·693-703
·
IF 0
Liu Jian,Zhao Yuheng,Liu Jialong,Wang Shouguo,Cheng Yan,Ji Muwei,Zhou Yuanmin,Xu Meng,Hao Weichang,Zhang Jiatao
Heterovalent doping represents an effective method to control the optical and electronic properties of semiconductor nanocrystals (NCs), such as the luminescence and electronic impurities (p-, n-type doping). Considering the phase structure diversity, coordination varieties of Cu atoms in Cu 2 S NCs, and complexity of Cu doping in II-VI NCs, monodisperse Cu 2 S NCs with pure hexagonal phase were synthesized firstly. Then through cation exchange reaction between Cd ions and well-defined Cu 2 S NCs, dominant Cu(I) doped CdS NCs were produced successfully. The substitutional Cu(I) dopants with controllable concentrations were confirmed by local atom-specific fine structure from X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) spectroscopy, elemental analysis characterizations from X-ray photoelectron spectroscopy (XPS) and the electron spin resonance (ESR) measurement. The dominant and strong Cu(I) dopant fluorescence was verified by their absorption and photoluminescence (PL) spectra, and PL lifetime. Finally, the band positions and the p-type conductivities of the as-prepared Cu 2 S and Cu(I) doped CdS NCs were identified by ultraviolet photoelectron spectroscopy (UPS) measurements. The high monodispersity of NCs enables their strong film-scale self-assembly and will hasten their subsequent applications in devices.
研究领域:
材料科学
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半导体物理
✓ 已验证
产品关联
DOI
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-12
·
IF 6.232
Li Zhe,Chen Xiaolan,Yu Lei,Li Huijuan,Chen Lu,Kang Qi,Shen Dazhong
A smartphone-based ratiometric fluorescence device was designed to monitor the reaction kinetic process under vigorous mixing conditions, demonstrated by the hydrolysis of Cs 4 PbBr 6 nanocrystals (NCs). In the presence of trace water, part of Cs 4 PbBr 6 NCs (non-fluorescent) was converted to CsPbBr 3 NCs (strong fluorescent). Using anthracene as the reference fluorophore, the brightness ratio of the green (from CsPbBr 3 NCs) to blue (from anthracene) components in the fluorescence image which was recorded in situ by the smartphone camera was measured as the signal for kinetic analysis. It was shown that the water-triggered conversion reaction from Cs 4 PbBr 6 NCs to CsPbBr 3 NCs follows the pseudo-second-order kinetic model in the early rapid hydrolysis stage (up to 4 min). With increasing water content, the hydrolysis of Cs 4 PbBr 6 NCs is promoted to yield more CsPbBr 3 NCs, which was used to determine trace water in n -hexane, dichloromethane, and toluene with detection limits of 0.031, 0.043, and 0.057 μL mL −1 , respectively. The device offers the advantages of portability and low cost for rapid field determination of trace water in hydrophobic organic solvents.
Graphical abstract
研究领域:
分析化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
·
2022
·
IF 11.504
Guangni Peng,Defeng Wu
Rod-like polysaccharide particles such as chitin nanocrystals (ChNCs) and cellulose nanocrystals (CNCs) have been widely used for the preparation of Pickering emulsion . Both are believed playing good role of particle emulsifiers. However, these two kinds of nanocrystals have completely different surface properties: electronegative CNC is more hydrophilic and has higher surface charge level as compared to electropositive ChNC. To reveal their difference as emulsifiers in Pickering emulsions is therefore of interest. In this work, ChNCs and CNCs with the same structural parameters (aspect ratio = 28) were used to prepare olive oil- in -water emulsions for a comparative study. The two kinds of nanocrystals show the same mechanical state in emulsions, behaving like rigid rods, instead flexible fibers because they have 10 4 level of effective stiffness. Therefore, their roles of emulsifying oil/water system are dominated by their surface properties: ChNCs reveal higher emulsifying capacity relative to CNCs due to better ChNC-oil affinity, and can even emulsify the oil/water (7/3 w/w) system with high oil fractions. However, ChNC-stabilized emulsions are not that stable to centrifugation as compared to CNC-stabilized emulsions at low oil fractions due to the formation of the cluster structure resulted from less coating of droplets. Thus, the former reveals higher strain sensitivity and stronger thixotropy than the latter in shear flow. The correlation between viscoelasticity and morphology/phase behavior of the two kinds of Pickering systems was assessed, then. This work provides valuable information on formulating preparation of Pickering emulsions by using different types of rod-like polysaccharide nanocrystals.
研究领域:
食品科学
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材料科学
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Menglu Li,Tian Tian,Yujing Zeng,Sha Zhu,Chao Li,Yongmei Yin,Genxi Li
As one of the emerging inorganic materials, perovskite nanocrystals (NCs) have inspired the development of various optoelectronic applications in recent years; however the effective utilization in biomedical fields is still limited. Herein, we report a quantitative measurement of broad-spectrum pore-forming toxins in complex media based on biomimetic CsPbBr 3 NCs. Specifically, by coating CsPbBr 3 NCs with phospholipid (CsPbBr 3 NCs@PL), the outer micelle membrane can not only serve as a shell to protect the stability of CsPbBr 3 NCs, but also interact with broad-spectrum biotoxins. Meanwhile, toxin-triggered transmembrane pore formation can cause water permeation, which breaks down the structure of CsPbBr 3 NCs@PL, generating striking fluorescent and electrochemical dual responses. Therefore, direct quantitative measurements of biotoxins are realized via dual-readout signals with inverse change trend, resulting in a detection limit of 50 nM. Our report represents the first example of CsPbBr 3 NCs for the develpment of biosensors. Meanwhile, such a label-free, cost-effective and widely applicable biomimetic CsPbBr 3 NCs@PL may present a valuable tool for the detection of biotoxin infections, and overcomes the limitations of perovskite materials in biosensing.
研究领域:
生物医学工程
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材料科学
·
毒理学
✓ 已验证
DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2012
·
IF 1.726
Shenjie Li,Daocheng Pan
Cu 2 SnSe 3 nanocrystals with a metastable zincblende and wurtzite structure have been successfully synthesized. The crystal structures were confirmed by means of X-ray diffraction and selected area electron diffraction . The lattice mismatch between Cu 2 SnSe 3 and ZnSe is only 0.26%, thus homogeneously alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals could be synthesized. The band gaps of nanocrystals can be tuned in a wide range of 2.75 to 0.92 eV; however the bowing parameter as high as 19.1 eV for alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals was observed. These low cost and dispersible alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals with a targeted band gap have a high potential in thin film solar cells.
研究领域:
材料科学
·
太阳能电池研究
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Yawei Yang,Wenxiu Que,Xinyu Zhang,Xingtian Yin,Yonglei Xing,Meidan Que,Hongyang Zhao,Yaping Du
A chloroform-assistant Se dissolution in oleylamine without trioctylphosphine and alkylthiol as the green precursor was used for facile and robust synthesis of quaternary selenide nanocrystals. The S 2− modified hydrophilic Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 nanocrystals were first prepared by a one-pot thermal decomposition route, followed by a bi-phase hydrophilic treatment process. As a proof of concept, the as-obtained hydrophilic nanocrystals were hybridized with ZnO microspheres as photosensitizers to achieve visible light-driven photocatalytic application; on the other hand, hybridized with NaYF 4 : Yb, Tm microplates to achieve near-infrared light-driven photocatalytic application. These photosensitized hybrids as photocatalysts expanded the light absorption from ultraviolet to visible even near-infrared region, which showed excellent photocatalytic Rhodamine B degradation under visible and near-infrared irradiation compared to pure ZnO and NaYF 4 : Yb, Tm, respectively. Therefore, these hydrophilic Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 nanocrystals are proved as efficient photocatalytic sensitizers due to the efficient utilization of the visible light and emissions upconverted from near-infrared light.
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
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Yinsheng Xu,Xiaoxi Li,Mengling Xia,Xianghua Zhang
Metal halide perovskite nanocrystals (PNCs) have demonstrated intense luminescence and short emission lifetime, which perfectly match the requirements of X-ray fast scintillators . However, the poor stability of PNCs restricts their applications. Herein, CsPbBr 3 NCs in a wide band-gap Cs 4 PbBr 6 perovskite single crystal (PSC) matrix for efficient light extraction is reported. Benefitting from the protection of the PSC matrix and the perfect lattice matching, the PNCs embedded PSC show highly minimized nonradiative recombination and greatly improved stability. Moreover, by controlling the chemical equilibrium, the self-absorption of PNCs is reduced and the quantum yield increased to 78.5%. Furthermore, the PNCs embedded PSC demonstrates an appreciable light yield of 15,290 photons MeV −1 , much higher than the commercial scintillator BGO (8200 photons MeV −1 ), and a decay time of 12.8 ns, significantly shorter than almost all the representative scintillators. This work demonstrates unambiguously the potential of PNCs embedded PSC for next-generation fast scintillators.
研究领域:
材料科学
·
光学工程
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
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