CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 36
·期 6
·1102-1107
·
IF 1.063
Hu Keyan,Xu Zian,Liu Yiting,Huang Fuqiang
Due to the quite sluggish charge-carrier separation in semiconductor photocatalysts, the photocatalytic activity of these materials is still far inferior than anticipated. Herein, a novel approach to reducing the packing factor(PF) of ZnIn 2 S 4 semiconductors to improve the charge-carrier separation is offered. The well-crystallized Zn 1 - x In 2 S 4- x ( x =0, 0.05, 0.1) powders were productively prepared through solid-state reactions. Their structures were verified by the high-resolution transmission electron microscopy, powder X-ray diffraction, and X-ray photoelectron spectroscopy. The PF values of Zn 1 - x In 2 S 4- x ( x =0, 0.05, 0.1) samples were calculated to be 0.683, 0.651, and 0.618, respectively. The reduction of the PF for Zn 1 - x ImS 4- x with increasing x can promote the separation of photoexcited carriers, and this process was endorsed by their photoelectric response and photoluminescence emission spectra. The Zn 0.9 In 2 S 3.9 sample with a lower PF value presents roughly 21 times higher photocurrent density and four times higher photodegrading rate of methyl orange than those of pristine ZnIn 2 S 4 .
研究领域:
材料科学
·
光催化
·
半导体物理
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2020
·Vol. 63
·期 12
·2539-2550
·
IF 6.098
Wang Chenyi,Tao Zhengwang,Zhou Yuanpeng,Zhao Xiaoyan,Li Jian,Ren Qiang,Guiver Michael D.
Increasing the local charge density of flexible side-chain cations in the hydrophilic segments of anion exchange membranes (AEMs) is helpful for improving their properties. However, due to limitations of structural design strategies and available synthetic methods, very few AEMs with more than four flexible side-chain cationic groups in hydrophilic segments have been reported. In order to further improve the hydroxide conductivity, alkaline stability and dimensional stability, herein we report a series of AEMs containing eight flexible side-chain cations in hydrophilic segments, based on poly(aryl ether sulfone)s (PAES). The synthesis, ion exchange capacity (IEC), water absorption, dimensional swelling, alkaline stability and hydroxide conductivity of the obtained membranes (PAES-8TMA-x) were examined and the relationships between structures and properties of different types of AEMs were also systematically compared. The resulting AEMs with IEC values of 1.76–2.76 mmol g −1 displayed comprehensively desirable properties, with hydroxide conductivities of 62.7–92.8 mS cm −1 and dimensional swelling in the range of 8.3% to 15.8% at 60°C. The IEC and hydroxide conductivity for a representative sample, PAES-8TMA-0.35, maintained 82.2% and 79.6% of the initial values after being immersed in 2 mol L −1 NaOH at 90°C for 480 h, respectively. This study expands the design and preparation of AEMs containing high local densities of flexible side chain cations, and provides a new strategy for new AEM materials.
研究领域:
材料科学
·
高分子化学
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能源材料
·
电化学
·
膜技术
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2021
·Vol. 64
·期 11
·2667-2674
·
IF 8.273
Yin Hang,Kong Qingkun,Zhang Ruiling,Zheng Daoyuan,Yang Bin,Han Keli
Lead-free double perovskite nanocrystals (NCs), such as Cs 2 AgInCl 6 , have attracted considerable attention as stable and non-toxic alternatives to lead-based perovskites. However, the low photoluminescence (PL) intensity of pristine Cs 2 AgInCl 6 limits its practical applications. In this study, a series of Cs 2 AgIn 1− γ − x Bi x La γ Cl 6 NCs were synthesized to break the parity-forbidden transition and modify the associated optical functionalities. A broadband bright warm-white emission in the visible region was achieved, with an excellent PL quantum yield of 60%. The dynamic mechanism, involving ultrafast transient absorption, suggests that high-efficiency PL is induced by triplet self-trapping exciton emission. The incorporation of La 3+ -Bi 3+ facilitated the singlet-triplet transition by increasing the lifetime and quickening the intersystem crossing process. This finding provides a reliable method for optimizing the optical properties of emerging lead-free halide perovskite NCs.
研究领域:
材料科学
·
光子学
·
纳米技术
·
光电子学
·
半导体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2014
·Vol. 16
·期 2
·1-11
·
IF 2.278
Zhang Qiang,Yang Ping,Chen Hsueh Shin,Huang Baibiao,Shen Jianxing
Phosphonic and carboxylic acids were used as capping agents to fabricate CdSe nanocrystals (NCs) through organic synthesis, leading to a controlled growth of the NCs with adjustable morphologies from dots to rods. The binding energies and steric hindrance of ligands dramatically affected the growth kinetics of CdSe NCs, and therefore the resulting geometry of NCs. The detailed investigations of ligand effect on the growth of NCs and an efficient control over the NCs morphology were presented. CdSe nanorods (NRs) with various aspect ratios were created for studying relation between the diameter of NRs and photoluminescence (PL). Consequently, a synergic use of PL spectra and transmission electron microscopy images allowed us to systematically investigate the relationship between morphology and PL properties of as-prepared CdSe rods. The PL properties of CdSe NRs were finally found to be strongly diameter dependent and weakly related to their lengths.
研究领域:
纳米材料
·
半导体纳米晶体
·
光电子学
·
胶体化学
·
光物理
✓ 已验证
DOI
高影响因子
IONICS
·
2016
·Vol. 22
·期 11
·2087-2093
·
IF 2.119
Yang F.,Yu Z.,Meng B.,Zhu Y. J.,Yang Q. Q.,Lin Z. L.,Zhou H. M.,Liang X. L.
The Sr 1 − x
Na
x
SiO 3 − x /2 samples (SNS, x = 0.2, 0.3, 0.4, 0.45) were prepared by spark plasma sintering (SPS) at a lower sintering temperature of 850 °C for a shorter holding time of 5 min. All SNS samples by SPS are composed of single monoclinic SrSiO 3 phase, and the grain sizes are in the range of 1.9 ± 0.5 μm. The measurement results of the electrical properties show that the conductivities of SPS samples are one order of magnitude higher than those of the samples by traditional sintering method. The ion transference numbers of SNS samples by SPS are all higher than 0.99 in the temperature range of 500∼650 °C, which demonstrates that the SNS has met the requirements as solid oxide fuel cell electrolytes and the SPS process is a promising candidate for preparations of SNS electrolytes.
研究领域:
材料科学
·
陶瓷
·
固态离子学
·
能源材料
✓ 已验证
DOI
高影响因子
Science China-Physics Mechanics & Astronomy
·
2024
·Vol. 67
·期 4
·1-8
·
IF 6.4
Qiao Yuxi,Wang Fuyi,Wang Huaiqiang,Tao Zicheng,Jiang Zhicheng,Liu Zhengtai,Cho Soohyun,Zhang Fayuan,Meng Qingkai,Xia Wei,Yang Yichen,Huang Zhe,Liu Jishan,Liu Zhonghao,Zhu Zengwei,Qiao Shan,Guo Yanfeng,Zhang Haijun,Shen Dawei
Unconventional fermions in the immensely studied topological semimetals are the source for rich exotic topological properties. Here, using symmetry analysis and first-principles calculations, we propose the coexistence of multiple topological nodal structure in LaSb 2 , including topological nodal surfaces, nodal lines and in particular eightfold degenerate nodal points, which have been scarcely observed in a single material. Further, utilizing angle-resolved photoemission spectroscopy, we confirm the existence of nodal surfaces and eightfold degenerate nodal points in LaSb 2 . The intriguing multiple topological nodal structure might play a crucial role in giving rise to the large linear magnetoresistance. Our work renews the insights into the exotic topological phenomena in LaSb 2 .
研究领域:
凝聚态物理
·
拓扑材料
·
量子材料
·
电子结构理论
✓ 已验证
DOI
高影响因子
Science China-Physics Mechanics & Astronomy
·
2023
·Vol. 67
·期 1
·1-6
·
IF 6.4
Zhang Yuhang,Liu Cong,Zhu Xiyu,Wen Hai-Hu
Recent claim of discovering above-room-temperature superconductivity ( T c ≈400 K) at ambient pressure in copper doped apatite Pb 10 (PO 4 ) 6 O has stimulated world-wide enthusiasm and impulse of motion. A lot of follow-up works have been carried out with controversial conclusions. To check whether superconductivity is really present or absent in the material, we need samples which should have a rather pure phase of Pb 10− x Cu x (PO 4 ) 6 O. Here we report the characterization results from the Pb 10− x Cu x (PO 4 ) 6 O with a fraction of about 97 wt.% inferred from the fitting to the X-ray diffraction pattern, if assuming Cu 2 S as the only impurity. The resistivity measurements show that it is a semiconductor characterized roughly by a ln(1/ T ) temperature dependence in wide temperature region without trace of superconductivity. Magnetization measurements show that it has a general ferromagnetic signal with a weak superparamagnetic background. Many grains of the sample show clear interactions with a NbFeB magnet. The detected Cu concentration is much lower than the expected nominal one. Our results show the absence of metallicity and superconductivity in Pb 10− x Cu x (PO 4 ) 6 O at ambient pressure, and suggest the presence of strong correlation effect.
研究领域:
凝聚态物理
·
材料科学
·
超导性
·
磁性
✓ 已验证
DOI
高影响因子
Science China-Physics Mechanics & Astronomy
·
2016
·Vol. 59
·期 2
·1-6
·
IF 1.575
Cheng Wei,Tong Xin,Hu QinGang,Mou YongBin,Qin HaiYan
P-15, a synthetic peptide of 15-amino acids, has been tested in clinical trials to enhance cell adhesion and promote osseointe- gration. This feature of P-15 has also inspired the development of designing new bone substitute materials. Despite the increasing applications of P-15 in bone graft alternatives, few studies focus on the mechanism of cell adhesion promoted by P-15 and the mechanical property changes of the cells interacting with P-15. In this article, we used atomic force microscope (AFM) based single cell indentation force spectroscopy to study the impact of P-15 on the stiffness and the adhesion ability of human jaw bone mesenchymal stem cells (HJMSCs) to hydroxyapatite (HA). We found that the stiffness of HJMSCs increases as the concentration of P-15 grows in short culture intervals and that the adhesion forces between HJMSCs and HA particles in both the presence and absence of P-15 are all around 30pN. Moreover, by calculating the binding energy of HJMSCs to HA particles mixed with and without P-15, we proved that P-15 could increase the adhesion energy by nearly four times. Scanning electron microscope (SEM) was also exploited to study the morphology of HJMSCs cultured in the presence and absence of P-15 on HA disc surface for a short term. Apparent morphological differences were observed between the cells cultured with and without P-15. These results explain the probable underlying adhesion mechanism of HJMSC promoted by P-15 and can serve as the bases for the design of bone graft substitute materials.
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 4
·1-10
·
IF 5.3
Shan Xiangyu,Lu Juan,Li Chao,Wu Qian,Li Huiling,Yang Shuning,Guo Yanjia,Song Yujia,Li Ruidan,Tian Li
An efficient and innovative electrochemiluminescence (ECL) sensor was developed for trace detection of cyfluthrin. The sensor utilized materials such as lotus root shaped carbon fiber (Co CNFs), cadmium selenide quantum dots (CdSe QDs), and Fe 3 O 4 to amplify Ru(bpy) 3 2+ signals. Co CNFs, with its large specific surface area and porosity, served the purpose of not only enhancing the stability of the sensor by fixing CdSe QDs and Ru(bpy) 3 2+ on the Co CNFs/GCE, but also facilitating electron transfer. CdSe QDs was involved in the luminescence reaction and collaborated with Ru(bpy) 3 2+ to enhance the sensor's sensitivity, while Fe 3 O 4 promoted electron transfer in the system due to its large surface area. The solid-state ECL sensor achieved satisfactory signal under the synergistic action of these components. The ECL signal of the sensor was quenched by cyfluthrin, and a favorable linear relationship was observed between the sensor and cyfluthrin in the concentration range 1 × 10 –12 to 1 × 10 –6 M. The detection limit of the sensor was 3.3 × 10 –13 M (S/N = 3). The utilization of lotus root shaped carbon fiber, CdSe QDs, and Fe 3 O 4 in the Ru(bpy) 3 2+ system demonstrated a synergistic effect for cyfluthrin detection, presenting a new approach for the rapid determination analysis of pesticide residues in foods. Graphical
研究领域:
分析化学
·
环境监测
·
食品安全
·
纳米材料
·
电分析化学
✓ 已验证
DOI
高影响因子
Frontiers of Physics
·
2024
·Vol. 19
·期 3
·1-10
·
IF 6.5
Chu Wenlong,Zhou Xilong,Wang Ze,Fan Xiulian,Guo Xuehao,Li Cheng,Yue Jianling,Ouyang Fangping,Zhao Jiong,Zhou Yu
Two-dimensional hafnium-based semiconductors and their heterostructures with native oxides have been shown unique physical properties and potential electronic and optoelectronic applications. However, the scalable synthesis methods for ultrathin layered hafnium-based semiconductor laterally epitaxy growth and its heterostructure are still restricted, also for the understanding of its formation mechanism. Herein, we report the stable sublimation of alkali halide vapor assisted synthesis strategy for high-quality 2D HfSe 2 nanosheets via chemical vapor deposition. Single-crystalline ultrathin 2D HfSe 2 nanosheets were systematically grown by tuning the growth parameters, reaching the lateral size of 6–40 µm and the thickness down to 4.5 nm. The scalable amorphous HfO 2 and HfSe 2 heterostructures were achieved by the controllable oxidation, which benefited from the approximate zero Gibbs free energy of unstable 2D HfSe 2 templates. The crystal structure, elemental, and time dependent Raman characterization were carried out to understand surface precipitated Se atoms and the formation of amorphous Hf–O bonds, confirming the slow surface oxidation and lattice incorporation of oxygen atoms. The relatively smooth surface roughness and electrical potential change of HfO 2 –HfSe 2 heterostructures indicate the excellent interface quality, which helps obtain the high performance memristor with high on/off ratio of 10 5 and long retention period over 9000 s. Our work introduces a new vapor catalysts strategy for the synthesis of lateral 2D HfSe 2 nanosheets, also providing the scalable oxidation of the Hf-based heterostructures for 2D electronic devices.
研究领域:
材料科学
·
纳米技术
·
半导体物理
·
电子器件
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2012
·Vol. 14
·期 11
·1-11
·
IF 3.287
Liu Peng,Wang Yunjiao,Wang Xue,Yang Chao,Yi Yanfeng
Polypyrrole-coated samarium oxide nanobelts were synthesized by the in situ chemical oxidative surface polymerization technique based on the self-assembly of pyrrole on the surface of the amine-functionalized Sm 2 O 3 nanobelts. The morphologies of the polypyrrole/samarium oxide (PPy/Sm 2 O 3 ) nanocomposites were characterized using transmission electron microscope. The UV–vis absorbance of these samples was also investigated, and the remarkable enhancement was clearly observed. The electrochemical behaviors of the PPy/Sm 2 O 3 composites were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge. The results indicated that the PPy/Sm 2 O 3 composite electrode was fully reversible and achieved a very fast Faradaic reaction. After being corrected into the weight percentage of the PPy/Sm 2 O 3 composite at a current density of 20 mA cm −2 in a 1.0 M NaNO 3 electrolyte solution, a maximum discharge capacity of 771 F g −1 was achieved in a half-cell setup configuration for the PPy/Sm 2 O 3 composites electrode with the potential application to electrode materials for electrochemical capacitors.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
DOI
高影响因子
CHINESE SCIENCE BULLETIN
·
2014
·Vol. 59
·期 27
·3449-3456
·
IF 1.365
Lei Ying,Liu Yu,Song Huiming,Sun Bo
Dendroclimatological techniques were employed to investigate the relationship between Chinese Pinus ( Pinus tabulaeformis Carr.) growth and climatic variability in the Mt. Yishan region of Shandong Province, China, over the past 253 years. Using regression analysis, the wetness index (WI) was reconstructed for the Mt. Yishan area for the period 1755–2007 AD based on tree-ring widths; predictor variables accounted for 40 % of the variance. The reconstructed time-series displayed an increasing trend after the late 1960s. Both the estimated and the observed WI for May–August were better correlated with precipitation than temperature during the period 1958–2007 AD, indicating that the contribution of precipitation to the WI was larger than temperature in the study area. The reconstructed WI was compared with the dryness/wetness index of China and land areas that were affected by droughts and floods using the agricultural statistics for Shandong Province. In addition, the WI time-series corresponded well with the peanut yield in Shandong Province at high frequency, which may be reasonable in the context of agriculture in Shandong. The 3-, 5- to 6- and 9- to 10-year periodicities detected in the time-series suggested that the reconstructed WI in the Mt. Yishan area may be related to large-scale climate variations.
研究领域:
树轮气候学
·
气候学
·
环境科学
·
农业科学
·
古气候学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）