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
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
·
生物化学
✓ 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
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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
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
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Tingting Chen,Jinqiong Xu,Pingping Yang,Qinglin Sheng,Jianbin Zheng,Wei Cao,Tianli Yue,Ming Zhou,Chengyue Wang
The paper reported the controlled synthesis of dumbbell-style AuPd and dendrite-like AuPt by a simple seed-mediated growth method, respectively. The composition and performances of the resulting nanomaterials were measured using transmission electron microscopy (TEM), high-resolution TEM (HRTEM), UV–vis absorption spectroscopy (UV–vis), X-ray photoelectron spectroscopy (XPS) and electrochemical methods. Moreover, the dumbbell-style AuPd modified glassy carbon electrode (GCE) showed excellent electrocatalytic ability towards nitrite with a fairly wide concentration range from 2 μM to 4200 μM and a 0.67 μM detection limit. The dendrite-like AuPt modified GCE showed excellent electrocatalytic ability towards tert-butyl hydroquinone (TBHQ) with a linear range from 0.35 μM to 625 μM and a relatively low detection limit of 0.075 μM. The electrochemical testing results exhibited the two kinds of sensors, Au 3 Pd 4 /GCE and Au 3 Pt 3 /GCE, possessed accepted selectivity, long-term stability and good reproducibility. Thus, the proposed two sensors could be applied in the determination of food samples. It is expected that the unique AuPd and AuPt are promising materials, which have great potential application in many fields of clinical diagnosis, new energy technologies, catalysis and sensors.
研究领域:
材料科学
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电化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Bijun Geng,Xiaobing Zeng,Qianwei Liang,Yuyu Chen,Li Tan,Rongkai Ye,Jianqiang Hu
Although the growth mechanisms (e.g., seed-induced growth and capping agent orientation) of bimetal nanocrystals (e.g., core–shell, alloy, segmented, and branched) from artificial experimental speculation and theoretical calculation have been widely accepted, precisely revealing their growth mechanisms is still tremendously challenging. In this work, we utilized redox reaction kinetics for the first time to successfully reveal the aqueous sequential growth mechanism between Au and Ag nanocrystals of segmented Ag-Au-Ag heterojunction nanorods (HJNRs) in a one-step and high-temperature aqueous system. Herein, electrode potentials of different electrical pairs (e.g., Ag+/Ag and AuCl4–/Au) at 200 °C could be calculated through using the Helgeson–Kirkham–Flowers state and other equations, from which whether Au and Ag nanocrystals grew successively and formed segmented Ag-Au-Ag HJNRs could be correctly assessed. The redox reaction kinetics mechanism can also explain well the aqueous-phase growth mechanisms of other bimetal nanocrystals and paves a promising avenue for the design and synthesis of other one-dimensional segmented metal nanostructures.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Wen-Xuan Hu,Jia-Yang Fu,Liang-Sen Liao,Ping Wang,Kexin Wang,Chang-Sen Jin,Xiuzhu Yu,Shuang-kui Du
Layer-by-layer assembly systems for functional proteins and polypeptides are gaining interest in food nutrition due to their health benefits. However, understanding the interactions between core-template materials and proteins remains challenging. This study investigated the complexation between oxidized and carboxymethylated starch nanocrystals (OSNC and CSNC) and lysozyme (LYS). Optimal complexation was achieved at pH 6 without ionic strength, and with a higher degree of modification. At LYS concentrations of 0.5 mg/mg and 0.25 mg/mg, OSNC and CSNC achieved maximum binding capacities of 0.417 mg/mg and 0.178 mg/mg, respectively. Micromorphologies showed LYS was primarily bound to the nano-lamellar surface of OSNC and CSNC. Although electrostatic interactions were predominant, hydrophobic interactions also contributed to CSNC-LYS complexation. LYS was nearly fully released (0.419 mg/mg for OSNC-LYS and 0.178 mg/mg for CSNC-LYS) with minimal impact on its structure and bioactivity. These findings provide a foundation for stabilizing proteins and polypeptides in functional foods.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yuehong Yin,Yukun Liu,Guohua Cao,Zhaoyue Lv,Haitao Zong,Yujie Cheng,Qifan Dong,Chen Liu,Ming Li,Baoqing Zhang
The Cs-Pb-Br system possesses excellent optical properties and unique phase transition characteristics due to soft lattice structures. Herein, a simple and green synthetic method based on self-assembly in Dimethyl formamide (DMF) is proposed to prepare CsPb 2 Br 5 nanocrystals (NCs) with typical tetragonal structure, which exhibit orange emission and small size around 3.87 nm. Interestingly, the phase transition from CsPb 2 Br 5 to CsPbBr 3 occurs easily in DMF through mechanical induction, while the metastable mixed-phase structural CsPbBr 3 NCs with an average size of about 5 nm appear and show bright yellow emission. Afterwards, in combination with the supersaturation crystallization method, stable cubic CsPbBr 3 NCs with 13 nm size are obtained and display the effective green emission. The synthesized CsPb 2 Br 5 and steady-state CsPbBr 3 NCs exhibit good optical stability in solution, while the metastable CsPbBr 3 NCs undergo a change in emission from yellow to green with increasing time.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 3
·2037-2048
·
IF 2.993
Wang Kelai,Liang Zheng,Li Jingling,Xu Xueqing,Cheng Xiaoling,Jin Hu,Xu Dehua,Xu Gang
Photoluminescent CuIn(Se x S 1 − x ) 2 (CISeS) nanocrystals (NCs) have been synthesized utilizing copper iodide (CuI) and indium acetate (In(Ac) 3 ) as metal cation precursors, Se powder and n -dodecanethiol (DDT) as selenide and sulfur source, combined with oleylamine and n -dodecanethiol as coordinate ligands at a moderate reaction temperature of 200 °C. The obtained CISeS NCs consisted of a gradient composition that the content of selenide increased from the nuclei to the surface. With the growth of NCs, they exhibited a tunable photoluminescent emission ranging from 722 to 830 nm which was size- and composition-dependent. The photoluminescent quantum yield of the NCs could be further enhanced from 1.2 to 40.7% after ZnS coating due to the formation of ZnCuIn(Se x S 1 − x ) 2 /ZnS (ZnCISeS/ZnS) core–shell structures with the alloyed core. The photoluminescence emission mechanisms of CISeS NCs indicated that the gradient composition structure of CISeS led to a gradient energy level of its conduction band (CB)/valence band (VB), resulting in the charge transfer from the nuclei to the surface through the quantized CB/VB. This transfer process has quenched fluorescence emission arising from the quantized CB/VB and defect states located in the nuclei, such as irradiation relaxation between quantized CB and \( V_{\text{Cu}}^{ \prime } \) . This mechanism could illuminate why the indium-rich CISeS NCs did not exhibit better photoluminescence properties.
研究领域:
材料化学
·
纳米科学
·
半导体光学
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光电子学
·
胶体化学
·
能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）