Materials
·
2019
·Vol. 12
·期 12
·1883
·
IF 2.972
Zhuhua Xu,Yanfei Lv,Feng Huang,Cong Zhao,Shichao Zhao,Guodan Wei
Monolayer tungsten disulfide (2D WS2) films have attracted tremendous interest due to their unique electronic and optoelectronic properties. However, the controlled growth of monolayer WS2is still challenging. In this paper, we report a novel method to grow WS2through chemical vapor deposition (CVD) with ZnO crystalline whisker as a growth promoter, where partially evaporated WS2reacts with ZnO to form ZnWO4by-product. As a result, a depletion region of W atoms and S-rich region is formed which is favorable for subsequent monolayer growth of WS2, selectively positioned on the silicon oxide substrate after the CVD growth.Keywords:monolayer WS2;ZnO;CVD;controlled growth
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 5
·2316
·
IF 4.6
Yazhou Qin,Dewang Fang,Yulun Wu,Yuanzhao Wu,Weixuan Yao
Porous Au nanocrystals (Au NCs) have been widely used in catalysis, sensing, and biomedicine due to their excellent localized surface plasma resonance effect and a large number of active sites exposed by three-dimensional internal channels. Here, we developed a ligand-induced one-step method for the controllable preparation of mesoporous, microporous, and hierarchical porous Au NCs with internal 3D connecting channels. At 25 °C, using glutathione (GTH) as both a ligand and reducing agent combined with the Au precursor to form GTH–Au(I), and under the action of the reducing agent ascorbic acid, the Au precursor is reduced in situ to form a dandelion-like microporous structure assembled by Au rods. When cetyltrimethylammonium bromide (C16TAB) and GTH are used as ligands, mesoporous Au NCs formed. When increasing the reaction temperature to 80 °C, hierarchical porous Au NCs with both microporous and mesoporous structures will be synthesized. We systematically explored the effect of reaction parameters on porous Au NCs and proposed possible reaction mechanisms. Furthermore, we compared the SERS-enhancing effect of Au NCs with three different pore structures. With hierarchical porous Au NCs as the SERS base, the detection limit for rhodamine 6G (R6G) reached 10−10M.Keywords:porous material;gold nanocrystals;controlled growth;SERS
研究领域:
纳米材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2019
·Vol. 10
·期 1
·75
·
IF 4.034
Siyuan Wang,Guang Wang,Xi Yang,Hang Yang,Mengjian Zhu,Sen Zhang,Gang Peng,Zheng Li
Two-dimensional (2D) layered semiconductor materials, such as transition metal dichalcogenides (TMDCs), have attracted considerable interests because of their intriguing optical and electronic properties. Controlled growth of TMDC crystals with large grain size and atomically smooth surface is indeed desirable but remains challenging due to excessive nucleation. Here, we have synthesized high-quality monolayer, bilayer MoSe2triangular crystals, and continuous thin films with controlled nucleation density via reverse-flow chemical vapor deposition (CVD). High crystallinity and good saturated absorption performance of MoSe2have been systematically investigated and carefully demonstrated. Optimized nucleation and uniform morphology could be achieved via fine-tuning reverse-flow switching time, growth time and temperature, with corresponding growth kinetics proposed. Our work opens up a new approach for controllable synthesis of monolayer TMDC crystals with high yield and reliability, which promote surface/interface engineering of 2D semiconductors towards van der Waals heterostructure device applications.Keywords:transition metal dichalcogenides (TMDCs);MoSe2;controlled growth;reverse-flow chemical vapor deposition (CVD)
研究领域:
材料科学
·
半导体物理
✓ 已验证
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 35
·6262-6268
·
IF 3.756
Siyan Yao,Tianzhi Li,Chenyang Yue,Xiaojun Xu,Binbin Zhang,Chaofan Zhang
Recently, one of the uranium-based heavy fermion systems, UTe2, has attracted enormous attention because of its potential spin triplet superconductivity, whose superconducting properties are closely related to their compositions and states of crystallization. In this work, the crystal growth of UTe2 crystals was systematically studied by the CVT method. Various growth parameters, including growth temperature, the ratio of uranium to tellurium, and the type and amount of transport agents, were investigated. A lower growth temperature (710 °C) results in a smaller size of the UTe2 crystals, and too high of a growth temperature (1060 °C) makes the nucleation rate go out of control. The ingredients with higher tellurium content (U : Te = 2 : 5) lead to larger single crystals, while a shortage of tellurium (U : Te = 2 : 3) tends to form polycrystals with smaller sizes. Among the three types of transport agents we used, iodine forms larger crystal sizes than AgBr and TeBr4. When the amount of iodine is excess (2.45 mg cm−3), the crystal surface becomes rough, while not enough iodine makes the crystal thin and even bent. We have found that centimetre-sized high quality UTe2 single crystals can be grown by using an appropriate amount of iodine as the transport agent at 860 °C. The nucleation rate of UTe2 crystals is mainly determined by temperature and iodine partial pressure, while the growth rate is more sensitive to the tellurium partial pressure. The oxidation process of UTe2 crystals was observed and is also discussed in this paper.
研究领域:
凝聚态物理
·
材料科学
·
超导体研究
·
晶体生长技术
·
强关联电子系统
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2013
·Vol. 15
·期 26
·5275-5282
·
IF 3.879
Shaodong Sun,Yuexia Sun,Xiaozhe Zhang,Hongjia Zhang,Xiaoping Song,Zhimao Yang
A surfactant-free strategy for controllable growth of various hierarchical CuO nanostructures was successfully achieved through a facile, one-pot solution-phase transformation of CuxMy(OH)z (M = SO42−, Cl−, NO3− and CH3COO−) precursors method without extra heat treatment in air. The formation of CuO nanostructures here is essentially determined by the species of CuxMy(OH)z precursors. The nanoparticle aggregation with controllable shapes can be formed under different concentrations of reactants. Hierarchical CuO nanoflowers with different branched building blocks were prepared by the transformation of Cu4(SO4)(OH)6 precursors. Hierarchical CuO nanospindles and nanoplates were fabricated by the transformation of Cu2(OH)3NO3 precursors. Hierarchical CuO nanoplate assemblies and nanoplates were synthesized by the transformation of Cu7Cl4(OH)10H2O and C8H6Cu3O104H2O precursors, respectively. Structural and morphological evolutions were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and field-emission scanning electron microscopy (FESEM). This study is of great importance in controllable synthesis of surfactant-free CuO nanostructures, because it not only enriches the family of CuO architectures but also offers a good chance to understand the nature of the solution-phase precursor transformation method for synthesizing CuO nanostructures. Significantly, it is believed that this surfactant-free solution-phase precursor-driven synthesis of nanostructures presented here might provide a green approach to design and growth other well-defined metal oxide nanostructures.
研究领域:
材料科学
·
纳米技术
·
无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Zhongbao Ma,Long-Fei Ren,Diwen Ying,Jinping Jia,Jiahui Shao
High-performance thin film composite polyamide (TFC-PA) membranes with controllable structure and transport properties are of great significance. However, TFC-PA membranes prepared by interfacial polymerization are far from ideal due to their quick and uncontrollable reaction process. In this study, we reported a novel strategy to fabricate TFC-PA membranes via an electrospray interface-less polymerization (EILP) technique with a miscible solvent system. The miscible solvent system facilitated both the stable and fine spraying of monomer solutions and the efficient polymerization of monomers, and thus resulting in the formation of a smooth and defect-free PA skin layer. Moreover, the crosslinking degree and thickness of the EILP membrane skin layer could be controlled easily by regulating the concentration and dose of sprayed monomers. Attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential and mean effective pore size were employed to characterize the EILP membrane and clarify the separation mechanism. The optimum EILP membrane showed excellent filtration performance with a high water flux of up to 17.7 L m −2 h −1 bar −1 , high salt rejection (98.2% of Na 2 SO 4 ) and complete dye rejection for Congo red. This study provides new insights into the understanding of electrospray procedures and enlightens the design and manufacture of advanced membrane materials through electrospray.
研究领域:
材料科学
·
膜技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Lianfu Zhao,Shanliang Chen,Lin Wang,Fengmei Gao,Xiaohong Yao,Weiyou Yang
Fabrication of SiC nanoarrays is highly recommended owing to the fact that it is the key to push forward them being applied in optoelectronic devices. Nevertheless, majority of the reported works involving the growth of SiC low-dimensional nanostructures were often carried out under the harsh conditions ( e.g., high temperatures and/or high pressures), which were teemed as the key obstacle for the accomplishment of their controllable and repeatable growth. In the current work, we reported the controllable and repeatable large-scale fabrication (up to centimeter×centimeter of width × length in area) of well-aligned, free-standing and transparent 4 H -SiC nanohole arrays via anodic oxidation of SiC wafers at room temperature and atmospheric pressure conditions. It was discovered that the cycle period of the pulsed voltage played a crucial role in the formation of highly uniform nanohole arrays. In the meantime, the diameters, wall thickness and depth of the nanoholes could be modulated through the customization of the cycle times. Additionally, a possible mechanism was proposed for the formation of nanohole arrays.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2015
·
IF 12.881
Xiaolu Zhuo,Xingzhong Zhu,Qian Li,Zhi Yang,Jianfang Wang
We report on a method for the preparation of uniform and length-variable Ag nanorods through anisotropic Ag overgrowth on high-purity Au nanobipyramids. The rod diameters can be roughly tailored from ∼20 nm to ∼50 nm by judicious selection of differently sized Au nanobipyramids. The rod lengths can be tuned from ∼150 nm to ∼550 nm by varying the Ag precursor amount during the overgrowth process and/or by anisotropic shortening through mild oxidation. The controllable aspect ratios, high purity, and high dimensional uniformity of these Ag nanorods enable the observation of Fabry–Pérot-like multipolar plasmon resonance modes in the colloidal suspensions at the ensemble level, which has so far been demonstrated only on Au nanorods prepared electrochemically with anodic aluminum oxide templates. Depending on the mode order and geometry of the Ag nanorods, the multipolar plasmon wavelengths can be readily tailored over a wide spectral range from the visible to near-infrared region. We have further elucidated the relationships between the multipolar plasmon wavelengths and the geometric dimensions of the Ag nanorods at both the ensemble and single-particle levels. Our results indicate that the Au nanobipyramid-directed, dimensionally controllable Ag nanorods will be an attractive and promising candidate for developing multipolar plasmon-based devices and applications.
研究领域:
纳米材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 16
·6473-6480
·
IF 8.067
Junhan Guo,Yang Tang,Longtao Li,Pengcheng Jia,Bo Song,Xin Liu,Xiaomeng Li,Zhenbo Deng,Zhidong Lou,Yufeng Hu,Feng Teng,Liang Qin,Yanbing Hou
Micro–nano cesium lead halide perovskites have become one of the most potential materials for optoelectronic applications due to their excellent photoelectric properties such as tunable band gap, high absorption efficiency, long carrier diffusion length, and high stability. Although significant efforts have been made to grow CsPbBr3 single crystal perovskites via solution processing, it is difficult to prepare discrete high-quality factors and small volumes of Fabry–Pérot (F–P) mode and whispering-gallery-mode (WGM) optical resonators on the substrate due to random nucleation and excessive nucleation points, which lead to the accretion of a large number of crystallites. In this work, CsPbBr3 crystallites with different aspect ratios have been prepared on poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA) modified glass substrates by combining the control of evaporation rate of anti-solvents with the coffee ring effect and Marangoni effect. Due to the hydrophobic properties of PTAA, the nucleation points are significantly reduced, resulting in the growth of high-quality and robust single crystals separated from each other. These crystallites exhibit a high-quality factor (Q = 1200–1600) with a threshold of 10–20 μJ cm−2. The results indicate that the prepared CsPbBr3 crystallites can be used as promising micro–nano F–P and WGM lasers.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·Vol. 35
·期 33
·2419319
·
IF 19
Shunhang Yang,Mengyu Liu,Shengnan Yue,Panpan Liu,Huiting Lin,Tongtong Gao,Xing Huang
2D layered Sb 2 Te 3 has emerged as a promising material for thermoelectric and optoelectronic applications. However, fabricating single-crystalline Sb 2 Te 3 flakes with the desired size, shape, and orientation remains challenging due to limited understanding of their growth mechanisms. In this study, how the substrate, growth time, carrying gas, and its flow rate influence the growth behavior of Sb 2 Te 3 flakes through a chemical vapor deposition (CVD) approach combined with van der Waals epitaxy (vdWE) is elucidated. By fine-tuning these growth parameters, Sb 2 Te 3 flakes with controlled size, morphology, and crystal orientation on mica substrates are successfully achieved. Notably, a record-high anisotropy ratio in Sb 2 Te 3 flakes exceeding 10,000 is obtained. Photodetectors fabricated from these flakes demonstrate excellent optoelectronic performance, achieving a responsivity of 1.34 A W −1 , a large external quantum efficiency (EQE) of 332%, and a high external specific detectivity (D * ) of 1.38 × 10¹⁰ Jones under a light power density of 10 mW cm − 2 . Moreover, the device exhibits modulated photocurrent under pulsed light, suggesting potential applications in optoelectronic synapses. This work provides detailed insights into the controlled growth of single-crystalline Sb 2 Te 3 flakes, offering unprecedented opportunities for exploring their fundamental properties in the development of next-generation thermoelectric and optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
半导体器件
·
二维材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 10
·期 7
·2681-2689
·
IF 7.393
Qing Zhang,Xin Ye,Yue Zheng,Yongshuai Wang,Lin Li,Zhansheng Gao,Jinxiong Wu,Huanli Dong,Dechao Geng,Wenping Hu
Two-dimensional (2D) crystals of conjugated polymers (2DCCPs) have attracted significant attention in the past few decades due to their superior and intriguing optoelectronic properties. With the increase in brain-inspired neuromorphic computing, 2DCCPs have also been employed in the construction of synaptic devices because they offer clear advantages of easy integration, high stability, long–range order and no biological rejection. However, pursuing controllable strategies to obtain high-quality and large-scale 2DCCPs remains a challenge on account of their intrinsic complex structures. Herein, we present a universal methodology to grow centimeter-scale 2DCCPs in a controlled manner within minutes by selecting an appropriate growth-assisting solvent and surfactant. The thickness of the as-produced 2DCCPs was down to two molecular layers. The photonic synaptic transistors based on the as-grown 2DCCPs could perform typical synaptic functions, including short-term plasticity, paired-pulse facilitation, long-term plasticity and spike intensity-dependent plasticity. The transistor was also proven to have potential application as a high-pass filter. This methodology shows great potential to be expanded to many other polymer systems and opens new pathways for large-area integrated wireless communication systems and artificial visual systems.
研究领域:
材料科学
·
神经科学
·
电气工程
·
光子学
·
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）