Journal of the American Chemical Society
·
2025
·
IF 15.6
Xu Cao,Jiongzhao Li,Xudong Qian,Chuyue Li,Xiaogang Peng
Here, we demonstrate that monocrystalline (free of stacking faults) wurtzite CdSe nanocrystals with monodisperse size, shape (dots, rods, or wires), and facet structure are synthesized in both strongly confined and weakly confined size regimes. Considering the unique c-axis of wurtzite CdSe, we introduce a new type of neutral ligand (e.g., zinc-alkanoate ones) to pair with their dominating nonpolar low-index facets. Nucleation of the stacking fault-free wurtzite seeds instead of zinc-blende tetrahedrons is identified as the key step, which is optimized by a set of conditions matching the neutral zinc-alkanoate ligands. In the following growth stage, conditions are much less stringent, although the neutral zinc-alkanoate ligands are still critical in achieving nearly atomically flat facets of those monocrystalline nanocrystals. In the strongly confined size regime, the ensemble photoluminescence (PL) full-width-at-half-maximum (FWHM) of wurtzite CdSe nanocrystals reaches a record low (59 meV). In the weakly confined size regime, dual-peak PL caused by thermal population is observed. Monodisperse and monocrystalline wurtzite CdSe nanocrystals show distinctively size-dependent optical properties, in comparison with their zinc-blende counterparts. Results here suggest that the atomically precise synthesis of colloidal semiconductor nanocrystals is feasible, implying an advanced class of nanomaterials for exploring various optical and optoelectronic applications.
研究领域:
材料科学
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纳米技术
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Yueling Xu,Qi Fu,Shuijin Lei,Lixiang Lai,Jinsong Xiong,Qinghuan Bian,Yanhe Xiao,Baochang Cheng
As the typical multifunctional materials, multinary metal chalcogenides have attracted tremendous attention due to their broad applications. In this work, quinary chalcogenide CuNi x Zn 2− x InS 4 ( x = 0–2) nanocrystals with a wurtzite structure have been successfully synthesized for the first time by a solution method. The phase structure analysis suggests that the fabricated wurtzite phase has a disordered structure in which all metal cations share the same position and have a random distribution in the unit cell. The transmission electron microscopy results reveal that the products show a morphological evolution from sphere-like nanocrystals of CuZn 2 InS 4 ( x = 0) to bullet-like nanocrystals of CuNi 2 InS 4 ( x = 2) together with a growing particle size. All the as-obtained wurtzite CuNi x Zn 2− x InS 4 nanocrystals show a strong and broad visible light absorption. More importantly, the band gap energy of these nanocrystals can be readily tuned from 2.20 eV to 1.44 eV by varying the value of x from 0 to 2, which decreases almost linearly with the composition x . This work demonstrates a new series of I–II 2 –III–VI 4 group chalcogenide semiconductors.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2022
·
IF 4.931
Yijun Fu,Yue Cheng,Chi Chen,Dawei Li,Wei Zhang
The effect of hydrothermal process on the morphology and piezoelectric performance of zinc oxide/polyvinylidene fluoride (ZnO@PVDF) composite nanofibers is rarely studied. In this work, highly aligned ZnO nanorods were epitaxially grown on the electrospun PVDF nanofibers to form ZnO@PVDF composite nanofibers with a pine-needle-like bionic structure. Nanofibers before and after hydrothermal reaction were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and piezoelectric analysis. Results demonstrated that hydrothermal reaction conditions, including mass ratio of ZnCl 2 to HMTA, ammonium hydroxide volume, hydrothermal reaction time and temperature should be carefully controlled and cooperated with each other to produce ZnO nanorods with ideal microstructure and piezoelectric performance. FTIR and XRD results confirmed the transformation of β phase in PVDF nanofibers from α phase in PVDF powder due to the elongation under strong electric field during electrospinning. Results of SEM and XRD certified the successful growth of ZnO nanorods with hexagonal wurtzite structure, which plays an important role in facilitating the percentage of β phase and the resulted piezoelectric capacity of ZnO@PVDF composite nanofibers. All of these characterizations suggest that the proposed pine-needle-like ZnO@PVDF composite nanofibers demonstrate promising potential in the wide application of electromechanical energy conversion.
研究领域:
材料科学
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纳米技术
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物理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 12
·7913-7923
·
IF 12.732
Xiaosheng Guo,Chuchu Cheng,Fangshu Xing,Caijin Huang
Rational structure design of semiconductor photocatalysts is meaningful to enhance their sunlight-driven hydrogen-evolution performance. Herein, we present a facile approach to prepare Cd1−xZnxS nanopopcorns with zinc blende/wurtzite phase junctions by using excess thioacetamide (TAA). The as-obtained Cd1−xZnxS samples were used for visible-light photocatalytic H2 evolution without a co-catalyst. The H2-evolution activity reaches 282.14 μmol h−1 mg−1, which is ca. 12 fold higher than that of Cd0.5Zn0.5S prepared with an equivalent dose of TAA. Meanwhile, an apparent quantum yield of 64.4% at 420 nm was achieved. Results demonstrated that the Cd1−xZnxS samples synthesized by using excess TAA improve light absorption and hydrophilicity, which is helpful for the photocatalytic reaction. Moreover, the existence of type-II ZB/WZ phase junctions promotes the separation and migration of photoinduced electron–hole pairs. This work provides a novel idea for the rational design of efficient Cd1−xZnxS-based photocatalysts.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Weiquan Yuan,Jingzhong Kuang,Dan Ding,Zheyu Huang
Herein, organic/inorganic multiple adsorption sites were constructed on halloysite to intensify the selective adsorption performance of the adsorbent for Al(III) in rare earth solutions. The adsorption heat behavior and thermodynamics of the composite for different ion systems were investigated using microcalorimetry. The results showed that chitosan formed a mesoporous membrane on the acid-treated calcined halloysite (Hal H) substrate through a strong electron interaction between the nitrogen atom of the amino group and the oxygen atom of Si O structure on Hal H. Wurtzite was loaded onto the chitosan mesoporous membrane as nanoparticles and partially oxidized to the ZnO phase of wurtzite. [email protected] demonstrated excellent adsorption capacity ( q max (Al 3+ ) was 102.04 mg/g), selectivity performance (Ks was 1583.06), adaptation to varying ion concentrations and structural stability in the mixed solution. Solution pH, ion concentration and temperature significantly affected the adsorption heat behavior and thermodynamics of the composite in different ion systems. The efficient selective adsorption of Al(III) by [email protected] was achieved through chelation with the amide and amino groups of chitosan and chemical interaction with sulfur groups of wurtzite. This work exemplifies a promising strategy for designing novel mineral materials with strong selective adsorption properties for the separation of Al(III) and rare earth ions.
研究领域:
材料科学
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环境化学
·
吸附科学
·
热力学
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矿物加工
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS & DESIGN
·
2018
·
IF 4.525
Liwang Liu,Hong Li,Zirui Liu,Ya-Hong Xie
By hot-injection method with altering the dose of oleylamine (OAm) in a reaction system, CuInS 2 (CIS) nanocrystal with tunable structure and band gap is synthesized. Through various measurements, including X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), it is demonstrated experimentally that when the dose of OAm is relatively high (2.0 and 2.5 ml in this work), the combination phase of pseudo-chalcopyrite/wurtzite are obtained with a surprising existence of nanotwins. Besides, the molar fraction of wurtzite is larger in the sample using 2.5 ml OAm in the reaction system. However, when the dose of OAm becomes low, (0, 1.0 and 1.5 ml), pure zinc-blende CIS pyramidal quantum dots (QDs) can be prepared. This indicates that oleylamine promotes the formation of wurtzite structure. In addition, the band gap is larger with increasing of OAm, following the quantum refinement effects. This work serves as a facile method of synthesizing CIS nanocrystal with tunable structure and band gap, which will be possibly applied in the fabrication of their optoelectronic devices.
研究领域:
材料科学
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纳米技术
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光电子学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Linxi Wang,Xudong Qian,Yang Ren,Hairui Lei,Xiaofei Hu,Dongdong Chen,Jiongzhao Li,Xiaogang Peng
The CdS shells are epitaxially grown onto monodisperse zinc-blende CdSe core nanocrystals in octadecene mixed with fatty amines, with the volume fraction of fatty amines in the epitaxy solution (VNH2) varying between 0 and 100%. The shape─except the nanoplatelets from the reactions with medium VNH2 (especially 20% VNH2)─and surface ligands of the resulting CdSe/CdS core/shell nanocrystals from all reactions can be unified through a two-step surface treatment. The internal lattice defects originated from zinc-blende/wurtzite stacking fault(s), i.e., wurtzite lattice domain(s) in the CdS shells and twin fault(s) in the zinc-blende region, can be systematically controlled by varying the VNH2 and remain unaltered during the surface treatments. Both twin faults and wurtzite CdS lattice domains neither affect the electronic structure of the core/shell nanocrystals nor create internal electronic defects for the nanocrystals. Photoluminescence decay dynamics of the dot-shaped core/shell nanocrystals with solely twin faults can be mono-exponential and near-unity radiative decay, but photoluminescence of those with wurtzite CdS domains would always decay with double-exponential even if the photoluminescence quantum yield is unity. The results here imply that the most common lattice defects related to the stacking faults for II–VI and III–V semiconductor nanocrystals can be managed for achieving high-quality optical properties.
研究领域:
材料科学
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纳米技术
·
半导体物理
·
光学性质
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 8
·10734-10749
·
IF 2.478
Kabir Fazal,Murtaza Adil,Saeed Azhar,Ghani Awais,Ali Anwar,Khan Saleh,Kaili Li,Qizhong Zhao,Kang Yao Kang,Yang Sen
Room temperature ferromagnetism with the doping of magnetic ions in the semiconducting host is the fundamental criterion for the potential use of spintronics material. In the present study, pure and (Fe, Tb) co-doped ZnO nanoparticles were well-prepared via the co-precipitation method, and corresponding microstructural, magnetic, and optical properties were investigated. The formation of Wurtzite hexagonal crystal structure of pure and doped ZnO was confirmed by X-ray diffraction (XRD) studies. No secondary phase was detected in all samples. Microstructural analysis reveals the spherical morphology of synthesized particles with the average size in the nanometer range. Fourier transforms infrared spectra show Tb–Zn–O stretching at 550 cm −1 . Optical absorption spectra show that the bandgap decreases and the absorption band slightly shift toward the visible region with increasing Tb doping, which may be due to the transfer of charge between the Tb ion 4f level and ZnO valance band. The photoluminescence (PL) spectrum exhibits a strong emission in the visible range, and PL emission intensity decreases with increasing Tb concentration and is anticipated to be due to the low recombination rate of electron–hole pairs. Most importantly, the room temperature ferromagnetism (RTFM) was observed in the doped ZnO nanoparticles, ascribed to the bound magnetic polaron (BMP) mechanism. The optical and magnetic outcome demonstrates that prepared (Fe, Tb) co-doped ZnO based dilute magnetic semiconducting (DMS) material are potential candidates for spintronics applications.
研究领域:
材料科学
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纳米技术
·
自旋电子学
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固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 16
·11595-11606
·
IF 2.993
Wu Keliang,Dong Xuejun,Zhu Junfang,Wu Pengcheng,Liu Chang,Wang Yixi,Wu Jianning,Hou Juan,Liu Zhiyong,Guo Xuhong
The nanostructured heterojunction photocatalysts are considered promising in photocatalytic reduction in the carbon dioxide. Herein, we demonstrate a simple sol–gel and hydrolysis process to design nanostructured TiO 2 /ZnO heterojunction, by using the biological template celery stalk. The nanostructured photocatalyst consists of anatase TiO 2 and wurtzite ZnO nanoparticles. A well-connected heterojunction, with uniformly distributed nanoparticles, on the pores and folds of celery stems, is obtained. The enhanced specific surface area of 55.5 m 2 /g is achieved. The crystal structure, morphology and surface composition are investigated by electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Furthermore, we demonstrate the photocatalytic performance of as-synthesized nanostructure TiO 2 /ZnO heterojunction. The photocatalytic yield, of CO 2 reduction into CH 4 , exhibits a five times increase, from 0.55 to 2.56 µmol h −1 g −1 , for the nanocomposite as compared to the pure TiO 2 . This enhanced performance corresponds to the efficient charge transfer and hindrance in the recombination of electron–hole pairs due to the optimum band positions of ZnO and TiO 2 . This study demonstrates the potential of using biotemplates to design efficient photocatalysts to convert CO 2 into useful solar fuels.
研究领域:
材料科学
·
环境科学
·
纳米技术
·
光催化
·
可持续能源
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Linfeng Wang,Jinke Bai,Tingting Zhang,Xiaoyue Huang,Tianyi Hou,Bing Xu,Dongyu Li,Qinghua Li,Xiao Jin,Yuxiao Wang,Xueru Zhang,Yinglin Song
The emission linewidth of quantum dots (QDs) is one of the important optical properties, which is essential for the applications of QD lasers, high-quality displays, and biological imaging. However, we know less about controlling emission linewidth and its underlying mechanisms. Here we introduce a wurtzite ZnSe shell onto a wurtzite CdSe core to produce asymmetric strain due to their large, anisotropic lattice mismatch. Such asymmetric pressure induces significant splitting (Δ AB ) between heavy-hole (hh) and light-hole (lh) in valence band (VB). We show that the emission intensity from the lh state (E lh ) is significantly suppressed with the increasing Δ AB caused by the strong asymmetric strain. We demonstrate that the exciton-phonon coupling (EPC) is greatly inhibited under the anisotropic lattice strain. The alloying process between the core and shell occurs under the strong lattice strain and raises the longitudinal-optical (LO) phonon energy (E LO ). Higher LO phonon energy declines LO phonon occupation numbers (N LO ) and synergistically reduces the EPC. The asymmetrically strained alloy QDs ensemble exhibits highly bright emission with ultra-narrow linewidths of 13.8 nm (∼520 nm) and 15.8 nm (∼620 nm). This concept of band structure regulation via asymmetric strain can provide a new platform for high-quality QDs beyond the currently achieved.
研究领域:
材料科学
·
光电子学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2019
·
IF 1.573
Junli Wang,Yajie Qiao,Tingting Wang,Kangmin Chen
In this work, we combine the catalytic growth and ligand control mechanisms to synthesize ultrathin/ultralong ZnSe nanowires (NWs). Ag 2 Se catalyst seeds initiate the NW growth and significantly cause the increase of the NW lengths up to several micrometers. The long-chain amine mixture of oleylamine and 1-dodecylamine acts as reaction medium and ligands (or surfactants) to control the sizes of Ag 2 Se seeds and ZnSe NWs within several nanometers (the mean diameter of NWs: ∼5.5 nm). The microstructure studies by HRTEM reveal the presence of zinc blende (ZB)/wurtzite (W) alternations and a number of stacking faults and twins within individual ZnSe ultrathin NWs. These NWs exhibit optical quantum confinement effect due to the diameters smaller than the theoretical exciton Bohr diameter of bulk ZnSe. Raman spectrum and photoelectronic performance under white light illumination are also presented.
研究领域:
材料科学
·
纳米技术
·
光学
·
固体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）