Materials Today Communications
·
2023
·
IF 3.8
Yuhui Chen,Ruihua Zhang,Zhenhua Hao,Yongchun Shu,Jilin He
In this study, MoO 2 was reduced by an unmixed carbon reduction method. Effects of reduction temperature, reduction time and distance between carbon and MoO 2 on the phase composition of reduction products were investigated. Results show that the phase change during the reduction process are MoO 2 →Mo 2 C→Mo with the increase of temperature. The reduced product is Mo 2 C when reduction temperature is 1000 °C and 1050 °C. Pure Mo can be obtained when the reduction temperature increases to 1100 °C. The reduced product changed from nearly spherical Mo particles with fine molybdenum dioxide particles attached on surface to polyhedron Mo particles with smooth surface when the distance between carbon and MoO 2 decreases from 10 mm to 1 mm. The reaction showed a similar change with the changes of the reaction time. The difference is that there will be residual Mo 2 C in reduced product when reduction time was 1 h. This method of carbon reduction can provide low carbon concentration by controlling the carbon distance to avoid the existence of molybdenum carbide in the product of molybdenum preparation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Liming Guo,Xin Wan,Jieyuan Liu,Xu Guo,Xiaofang Liu,Jiaxiang Shang,Ronghai Yu,Jianglan Shui
Synergistic effects have been applied to a variety of hybrid electrocatalysts to improve their activity and selectivity. Understanding the synergistic mechanism is crucial for the rational design of these types of catalysts. Here, we synthesize a MnCo2O4/Co–N–C hybrid electrocatalyst for the oxygen reduction reaction (ORR) and systematically investigate the synergy between MnCo2O4 nanoparticles and Co–N–C support. Theoretical simulations reveal that the synergy is closely related to the distance between active sites. For a pair of remote active sites, the ORR proceeds through the known 2e- + 2e- relay catalysis while the direct 4e– ORR occurs on a pair of adjacent active sites. Therefore, the formation of the undesired byproduct (H2O2) is inhibited at the interface region between MnCo2O4 and Co–N–C. This synergistic effect is further verified on an anion-exchange membrane fuel cell. The findings deepen the understanding of synergistic catalysis and will provide guidance for the rational design of hybrid electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Xiaoran Wu,Xiang Xue,Jinghang Wang,Hewen Liu
Phoretic swarming and collective transport of colloidal particles in response to environmental stimuli have attracted tremendous interest in a variety of fields. In this work, we investigate the light-actuated motion, aggregation, and light-guided long-distance mass transport of silica microspheres in simple spiropyran solutions under the illumination of UV spot sources. The phototactic motion is confirmed by the dependence of swarming on the illumination intensity and spiropyran concentrations, ON–OFF switching tests, pattern-masked UV sources, etc. The aggregates formed via swarming of silica spheres can chase after a moving UV source, however, relying on a critical speed of the UV source. Only when the UV source speed is below the critical value, the aggregates follow the UV spot at a constant relative speed to the light spot. Analysis on the shape of silica microsphere currents indicates that continuous illumination of the UV spot source and resultant chemical gradients are important for the formation of steady microsphere currents. Light-guided aggregation and long-distance mass transport are interesting for targeted delivery and remote-controlled enrichment of environmental hazards.
研究领域:
材料科学
·
物理学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2015
·
IF 1.644
Han Wang,Shenneng Huang,Feng Liang,Peixuan Wu,Minhao Li,Sen Lin,Xindu Chen
Multinozzle electrospinning systems are designed to increase productivity, while near-field electrospinning (NFES) systems are designed to deposit solid nanofibers in a direct, continuous, and controllable manner. In this paper, several multinozzle NFES setups are tested. The experiment reveals that the deposition distance becomes larger when working distance and needle spacing increase, and the influence of voltage is relatively weaker. The deposition of double nozzle NFES has been studied with Coulomb’s law and theoretical derivation has been verified by the experimental conclusion. The experiment result and theoretical derivation are helpful to get different distance of direct-written fibers by adjusting working distance or needle spacing to change distance of fibers largely and adjusting voltage to change distance slowly. Through these efforts, it is convenient to adjust the distance of straight fibers in multinozzle system.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 45
·29003-29009
·
IF 4.036
Fan Sun,Zhao Liu,Jiawei Lin,Jun Deng,Zhongnan Guo,Wenxia Yuan
The magnetic semiconductor in a two-dimensional system is a major subject for both theoretical and experimental investigations. Here we report the synthesis of a new quaternary manganese chalcogenide KMnCuTe2, which shows layered structure and antiferromagnetic (AFM) semiconducting features. Single crystals of KMnCuTe2 were obtained using a self-flux method and based on single-crystal X-ray diffraction, KMnCuTe2 adopts the ThCr2Si2-type structure composed of edge-sharing tetrahedral layers separated by K+ cations. The Mn and Cu atoms randomly distribute in the centre of tetrahedral units. Attributed to the large radius of Te, KMnCuTe2 has large lattice parameters (a = 4.3115(3) Å and c = 14.9360(20) Å), leading to a long metal–metal distance (3.049 Å) in the tetrahedral layers. Based on the experiments and theoretical calculations, KMnCuTe2 exhibits a G-type AFM interaction with the transition temperature at around 225 K and an indirect semiconducting nature with the band gap of 0.95 eV. The magnetic semiconducting property of KMnCuTe2 is unique in AMnMCh2 systems (A = Li, Na, K, M = Cu, Ag and Ch = S, Se, Te), which could be associated with the large metal–metal distance. Our work not only highlights the role of metal–metal interactions on regulating the properties of ThCr2Si2-type compounds, but also provides a feasible strategy to obtain the layered magnetic semiconductor.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 7
·3592-3598
·
IF 2.936
Pingping Feng,Xinying Wang,Yushuang Zhao,De-Cai Fang,Xiaojing Yang
Energy transfer between rare earths in layered rare-earth hydroxides (LRHs) is worth the intensive study because the hydroxyls that act as the bridge connecting the neighbouring rare earths would generate non-radiative transitions. This study focuses on the energy transfer in the intralayer and the adjacent layers of LRHs. A series of LEuxTb1−xHs (x = 0, 0.05, 0.2, 0.5, 0.8, and 0.95) was synthesized, the basal spacing (dbasal) was adjusted from 8.3 to 46 Å through ion-exchange process, and unilamellar nanosheets were prepared through a delamination process. The luminescence behaviours of the samples demonstrated the following: (1) for the delaminated nanosheets, the quenching effect of both Eu3+ and Tb3+ was hardly observed. This implies that in the intralayer, the efficiency of energy transfer is extremely low, so that highly-concentrated co-doping does not influence the luminescence and by controlling the Eu/Tb molar ratio, white light can be obtained. (2) For small dbasal, e.g., 27 Å, the fluorescence quenching of Tb3+ and Eu3+ was remarkable, while for large dbasal, e.g., 46 Å, the emission of Tb3+ emerged and the self-quenching between Eu3+ ions weakened. (3) The energy transfer efficiency deceased with an increase in the distance between adjacent layers. In other words, either the energy transfer between Eu3+ and Tb3+ or the energy migration between Eu3+ ions was more efficient when they were located in adjacent layers than in intralayers even when they were the nearest neighbours.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2016
·
IF 5.554
Ye Sha,Yunlong Xu,Dongliang Qi,Yuanxin Wan,Linling Li,Hong Li,Xiaoliang Wang,Gi Xue,Dongshan Zhou
We report on the synthesis of heterotelechelic α,ω-dye-labeled polystyrene and poly(methyl methacrylate) via a combination of site-specific atom transfer radical polymerization (ATRP) and click chemistry. By using the advantages of the living polymerization characteristics and a robust coupling efficiency, the Förster/fluorescence resonance energy transfer (FRET) pairs (i.e., carbazolyl and anthryl) were dictated to be at the near-stoichiometric chain ends. The distribution of the end-to-end distance was well described by the energy transfer response of the fluorescent groups between chain ends, which is in reasonable agreement with Gaussian statistics. The synthetic approach described here provides an opportunity to prepare polymeric materials with customized responsive elements and in-depth insight into the statistical scaling dimension of polymers.
研究领域:
高分子化学
·
材料科学
·
光物理学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2022
·
IF 3.574
Jian Zou,Zhuo Chen,Sheng-Ji Wang,Hao-Yang Mi,Xiang-Shu Hu,Zhi Zhang,Ying-Hui Shang,Xin Jing
Hydrogel always suffers from poor sensitivity which limits their applications in the flexible devices. To address that, we designed zigzag structures onto the rectangular hydrogel which are commonly employed in recent years. The special designed structure tremendously increased the travelling distance of the mobile ions in the conductive hydrogel during the deformation of the zigzags, which lead to significant change in the resistance of hydrogel upon stretching. Therefore, the structured hydrogel achieved outstanding sensitive performance with the gauge factor (GF) of 2.89, which was almost two times higher than that of the original one. Therefore, we proposed a feasible way to adjust the sensitivity of the hydrogel, which holds great potential to be used for flexible strain sensors in healthcare, e-skin and artificial intelligence devices.
研究领域:
材料科学
·
生物医学工程
·
柔性电子
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Wenfang Wang,Bowen Shi,Chang He,Siyi Wu,Lan Zhu,Jiang Jiang,Lingyun Wang,Li Lin,Jian Ye,Huan Zhang
The prognosis analysis of gastric cancer is critical for selection of treatments and development of advanced therapeutic methods. A prognosis approach that is accurate, fast, convenient, and of low cost for gastric cancers is in high demand. Raman spectroscopy is a label-free and non-destructive technique to provide molecular fingerprints of biological samples, holding promises for cancer prognosis. However, the major challenge of gastric cancer prognosis lies in the widely existing tumor heterogeneity, which leads to unexpected spectral variations within one type of samples. In this work, we have developed the Euclidean distance (ED)-based Raman spectroscopy (EDRS) method for the prognosis analysis of gastric cancer to eliminate the influence of tumor heterogeneity. Raman spectra were first collected on the slices of paraffin-preserved tumor tissues from gastric cancer patients. A standard spectrum to represent the ‘worst prognostic tumor cells’ was then established. The similarity between each spectrum of tissues and the standard spectrum was assessed by ED, to provide a direct assessment on the prognosis status. We have successfully classified the patients into poor and favorable prognosis groups, either based on the averaged regional ED values (sensitivity of 75 %, specificity of 96.8 %), or based on the minimal ED values at the patient level (sensitivity of 90 %, specificity of 100 %). EDRS was also investigated for survival analysis (AUC = 0.955), much better than the commonly applied post-neoadjuvant therapy (ypTNM) category (AUC = 0.718). Our work highlights EDRS as a rapid, accurate, low-cost and robust tool for heterogeneous cancer-related prognosis assessment and survival prediction, providing new insights for spectroscopic tumor analysis.
研究领域:
医学
·
分子生物学
·
光谱学
✓ 已验证
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2023
·
IF 15
Xuan Huang,Bingyan Xu,Jie Feng,Shengnan Hu,Wenjie Dou,Tang Yang,Changhong Zhan,Shangheng Liu,Yujin Ji,Youyong Li,Chih-Wen Pao,Zhiwei Hu,Qi Shao,Xiaoqing Huang
Phase regulation of noble metal-based nanomaterials provides a promising strategy for boosting the catalytic performance. However, realizing the continuous phase modulation in two-dimensional structures and unveiling the relevant structure-performance relationship remain significant challenges. In this work, we present the first example of continuous phase modulation in a library of Pd–Te hexagonal nanoplates (HNPs) from cubic-phase Pd4Te, rhombohedral-phase Pd20Te7, rhombohedral-phase Pd8Te3, and hexagonal-phase PdTe to hexagonal-phase PdTe2. Notably, the continuous phase regulation of the well-defined Pd–Te HNPs enables the successful modulation of the distance between adjacent Pd active sites, triggering an exciting way for tuning the relevant catalytic reactions intrinsically. The proof-of-concept oxygen reduction reaction (ORR) experiment shows a Pd–Pd distance-dependent ORR performance, where the hexagonal-phase PdTe HNPs present the best electrochemical performance in ORR (mass activity and specific activity of 1.02 A mg–1Pd and 1.83 mA cm–2Pd at 0.9 V vs RHE). Theoretical investigation reveals that the increased Pd–Pd distance relates to the weak *OH adsorption over Pd–Te HNPs, thus contributing to the remarkable ORR activity of PdTe HNPs. This work advances the phase-controlled synthesis of noble metal-based nanostructures, which gives huge impetus to the design of high-efficiency nanomaterials for diverse applications.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Crystals
·
2024
·Vol. 14
·期 10
·910
·
IF 2.4
Meihong Huang,Junhui Lin,Zhiyong Liang,Shaowei Chen,Yuling Zhong,Feng Wang,Bixian Chen,Dongxia Zhang
The addition of flexible Cu2ZnSnS4 (CZTS) thin film solar cells to titanium (Ti) substrates is an attractive way to achieve the low-cost manufacturing of photovoltaics. Prior research has indicated that the appropriate diffusion of Ti elements can enhance the crystalline growth of CZTS films. However, the excessive diffusion of Ti has been shown to adversely affect the photovoltaic performance of CZTS photovoltaic devices. Therefore, it is essential to regulate the diffusion of Ti elements within CZTS thin films to optimize their photovoltaic properties. The tendency for Ti substrate elements to diffuse into CZTS films is also influenced by the activation energy associated with these Ti elements. The sulfurization temperature is posited to be a critical factor in modulating the diffusion and activation energy of Ti elements within CZTS thin films. Consequently, this research investigates the alteration of the sulfurization temperature of CZTS thin films in order to enhance the properties of these thin films and to examine the diffusion behavior of titanium elements. The results reveal that as the sulfurization temperature increases, the diffusion of Ti elements within the CZTS thin films initially increases, then decreases, and subsequently increases again. This pattern suggests that the diffusion of Ti elements is affected not only by the activation energy of the Ti elements but also by the defect hopping distance within the CZTS thin films. Notably, at a sulfurization temperature of 550 °C, the grains at the base of the CZTS thin film demonstrate an increased density, which is associated with a reduced defect hopping distance, thereby hindering the diffusion of Ti elements within the CZTS thin films. Furthermore, at this specific sulfurization temperature, the slope of the current–voltage (I–V) curve for the CZTS/Ti structure reaches its maximum, indicating optimal ohmic contact characteristics.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Min Li,Jian Xiao,Lin Chen,Bo Ren,Zhanjun Liu,Yuexin Guo,Yali Wang
In this study, the effect of mesoporous silica nanoparticles (MSNs) particle size on the diffusion distance of ibuprofen (IBU) is revealed. MSNs with different particle sizes of 50, 100, 200, 300, and 400 nm were synthesized using sol-gel method. Structure features were characterized by small-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N 2 adsorption-desorption. Using ibuprofen as the model drug, the optimal IBU unilateral diffusion distance was obtained by measuring the IBU loading per square meter. Results indicated the MSNs with a particle size of 100 nm exhibited the highest pore utilization and the optimal unilateral diffusion distance of IBU in MSNs was about 50 nm. On this bases, hollow mesoporous silica nanoparticles (HMSNs) were prepared to increase the loading of IBU. The optimal drug loading was achieved when the thickness of the shell was equal to the optimal unilateral diffusion distance, further demonstrating the relationship between the optimal diffusion distance and the drug loading.
研究领域:
药剂学
·
材料科学
✓ 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）