CHINESE CHEMICAL LETTERS
·
2016
·Vol. 28
·期 1
·49-54
·
IF 1.947
Qi-Feng Li,Chao Wang,Xiao-Zheng Lan
Latent heat storage performance of a layered perovskite-type compound, 1-C 14 H 29 NH 3 ) 2 ZnCl 4 (C 14 Zn), embedded in a series of silica gel (SG) with pore sizes of d = 15–200 nm is investigated using differential scanning calorimetry (DSC), and powder X-ray diffractions (XRD). C 14 Zn in the nanopores of silica gel shows size-dependent phase transition temperature, enthalpy change and supercooling. They have a stable transition temperature and heat capacity at each size in a short-term thermal cycling. Similar X-ray diffraction patterns are observed for the nano-sized and the bulk C 14 Zn. The encapsulation of a phase change material in nanopores is a new way of tuning its thermal energy storage properties for a wider range of temperature regulation.
研究领域:
材料科学
·
热力学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2018
·
IF 2.795
Maogang He,Siqi Liu,Lihang Bai,Xiangyang Liu
Magnetic ionic liquids (MILs), combines the general properties of ionic liquid with magnetic properties, are starting to attract interest in the field of propane/propylene separation and CO 2 capture. Solubility data of propane, propylene, cyclopropane and CO 2 in magnetic ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate [bmim][FeCl 4 ] at temperatures of (303, 313, 323, 333, 343) K and pressures up to 3300 kPa were determined in the present work. The relative expanded uncertainty of solubility measurement is estimated to be less than 4% with a level of confidence of 95%. The Henry’s constants for the four gases in [bmim][FeCl 4 ] and selectivity of C 3 H 6 /C 3 H 8 in [bmim][FeCl 4 ] were calculated. And the thermodynamic properties of solvation concerned about the Gibbs energy (Δ sol G ∞ ), the enthalpy (Δ sol H ∞ ) and the entropy (Δ sol S ∞ ) of solvation were also obtained to offer knowledge for understanding the progress of gases dissolved in [bmim][FeCl 4 ]. The experimental results were correlated with a modified KK equation and NRTL equation.
研究领域:
化学工程
·
分离科学
·
物理化学
·
环境化工
·
绿色溶剂技术
✓ 已验证
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Junliang Wang,Shuyan Zhou,Ke Bei,I-Ming Chou,Chunmian Lin,Zhiyan Pan
This work developed a new method for measuring the volume expansion of a CO 2 + n -dodecane mixture, using a fused silica capillary cell (FSCC), combined with a heating-cooling stage and a confocal Raman spectrometer. The cell was constructed on the micron scale to reduce the temperature gradient and reagent consumption. The results confirmed the feasibility of this method that using Raman spectra to verify phase equilibrium, a digital camera to record images of the CO 2 + n -dodecane mixture and a micrometer to measure the volume, a section of water (water seal) between n -dodecane and gas phase to prevent n -dodecane from evaporating. It was shown that the volume expansion factor of the mixture increased with pressure going from 1.0 to 10.0 MPa, but decreased as the temperature was raised from 30 to 80 °C. In addition, a positive quadratic relationship ( R 2 > 0.99) was obtained between Raman peak intensity ratio and volume expansion factor, such that more volume expansion factors could be obtained according to the equations with measured Raman peak intensity ratio data. This experiment widens the ranges of temperature and pressure in the measurements of the volume expansion, and provides more volume expansion data for CO 2 -enhanced oil recovery.
研究领域:
物理化学
·
能源科学
·
油气开采
·
光谱分析
·
热力学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2024
·Vol. 53
·期 10
·6553-6562
·
IF 2.2
Zhang Yu,Ma Jianli,Chen Chen,She Yubin
In this work, non-stoichiometric Li 2(1+ x ) Mg 3 Ti 4 O 12 (L x MTO, x = 0.00–0.05) ceramics with excess lithium were prepared through a simple reaction sintering route to suppress lithium volatilization. According to the characterization of the phase composition and microscopic morphology of the pellets, single-phase L x MTO ceramics with a good microstructure were obtained. Excess lithium effectively inhibited the volatilization and optimized the morphology of the ceramics. A trend in relative density with an initial increase followed by a steep decrease was a predominant observation with the change in dielectric properties. The permittivity of the samples was dominated by the relative density and distortion of the [TiO 6 ] octahedron structure caused by Li + . The dielectric loss primarily originated from the refraction loss and scattering generated by pores, and the grain boundaries also contributed to the loss in the quality factor. Ultimately, at 1220°C, the Li 2.08 Mg 3 Ti 4 O 12 ceramics exhibited excellent microwave dielectric properties: ε r = 17.83, Q × f = 69,823 GHz and τ f = −18.19 ppm/°C.
研究领域:
材料科学
·
无机非金属材料
·
介电材料
·
陶瓷学
·
固态化学
·
电子材料
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2021
·Vol. 65
·期 3
·721-731
·
IF 8.273
Xu Hui,Jin Meng,Geng Jing,Zhang Shengbo,Zhang Haimin
The decentralized production of H 2 O 2 via a two-electron oxygen reduction reaction (2e − ORR) has emerged as a promising alternative to the energy-intensive anthraquinone (AQ) process. However, its practical application requires 2e − ORR electrocatalysts with high activity and selectivity. Herein, we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers (Ni-NPs/BCCF) via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2e − ORR to H 2 O 2 . By tuning the amount of Ni precursor, the best electrocatalytic performance toward 2e − ORR was achieved for Ni-NPs/BCCF-20.7, affording a high H 2 O 2 selectivity of ∼90% and an onset potential of 0.75 V vs. reversible hydrogen electrode (RHE) in an alkaline electrolyte. Ni-NPs/BCCF-20.7 achieved the largest H 2 O 2 yield rate of 162.7 ± 13.7 mmol g cat −1 h −1 and the highest Faradaic efficiency of 93.9% ± 4.2% at 0.2 and 0.5 V vs. RHE from the bulk ORR system, respectively. Theoretical calculations revealed the more favorable “end-on” adsorption configuration of molecular oxygen on the exposed Ni(111) plane, which can effectively suppress the O-O bond dissociation, resulting in high selectivity for H 2 O 2 generation.
研究领域:
材料化学
·
电化学
·
纳米催化
·
能源科学
·
环境工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 16
·23258-23265
·
IF 5.532
Jianlong Chai,Yabin Zhu,Xing Gao,Tielong Shen,Lijuan Niu,Shufen Li,Peng Jin,Minghuan Cui,Zhiguang Wang
Al 2 O 3 /SiC ceramic composites with different SiC contents have been prepared by powder metallurgy at 1600 °C for 120 min at 30 MPa pressure. The effect of second phase particles on the microstructure and mechanical properties of composites have been studied. The results show that SiC particle has a significant impact on the matrix subjected to residual stress, and on the microstructure of the composites as well. The average grain size of alumina matrix decreases as the SiC particle content increases. Simultaneously, it has been found that the mechanical properties of the material are significantly enhanced in comparison with monolithic Al 2 O 3 . The highest strength and toughness are obtained when the SiC content is 15 vol%, and the values are 1237 MPa and 5.68 MPa m 1/2 , respectively. The mechanisms of strengthening and toughening have been discussed.
研究领域:
材料科学
·
陶瓷学
·
复合材料工程
·
固态物理
·
粉末冶金
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2018
·
IF 2.207
Hongyu Shi,Na Li,Zhixia Sun,Tianqi Wang,Lin Xu
TiO 2 nanoparticles are commonly used as versatile precursors to make functional nanocomposite materials. However, the surface defects at grain boundaries of TiO 2 nanoparticles significantly affect the photoelectric properties of TiO 2 nanomaterials . In this work, we firstly prepared nanocomposites of TiO 2 and polyoxometalates (POMs) in which different POMs, including titanium-substituted POMs K 5 [PW 11 TiO 40 ] and K 7 [PW 10 Ti 2 O 40 ], are incorporated with TiO 2 nanoparticles so as to make an interface modification on grain boundaries of TiO 2 nanoparticles. Then the photoconductivities of the TiO 2 /POM nanocomposites were investigated through measurement of photocurrent responses, current-voltage curves, Mott-Schottky plots and surface photocurrent spectra. Compared with pure TiO 2 nanoparticles, TiO 2 /POM nanocomposites exhibit superior photoelectric properties, benefitting from the interface modification from different POMs. The gas sensing performance for acetone was also explored by use of the as-prepared photoconductive devices, and TiO 2 /PW 11 Ti exhibited a high gas sensing performance.
研究领域:
材料科学
·
纳米科技
·
半导体物理
·
传感器技术
·
光电子学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2013
·Vol. 38
·期 25
·10932-10938
·
IF 3.548
H. Wang,J. Zhang,J.W. Liu,L.Z. Ouyang,M. Zhu
In this study, alkali hydroxides (NaOH, LiOH, KOH) were attempted as new-type catalytic additives to improve the hydrogen storage properties of MgH 2 by ball milling . It is shown that the additives readily react with the MgH 2 to form perovskite-structured NaMgH 3 and KMgH 3 , but not the LiMgH 3 . Although the in-situ formed perovskite hydrides remain stable during hydriding/dehydriding cycles, both NaMgH 3 and KMgH 3 show predominant catalytic role on the hydriding and dehydriding of MgH 2 . In contrast, the LiOH modified MgH 2 presents much inferior sorption kinetics because of the absence of LiMgH 3 . The catalytic mechanism of perovskite hydrides can be explained by the high hydrogen mobility in the perovskite structure . This study shows that such cheap hydroxides could be used as efficient catalysts to improve the hydrogen storage properties of high-capacity metal hydrides and complex hydrides .
研究领域:
材料科学
·
无机化学
·
能源化学
·
氢能存储
·
金属氢化物
·
固态储氢
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Die Su,Jianping Yang,Qingshui Hong,Min Yang,Jiaxing Wen,Qianfu Wang,Hai Hu,Li Liu,Xiukang Yang
Pseudo-capacitive materials show long cycling life as anode of K-ion battery (KIBs), yet low specific capacity and poor rate performance. Herein, the porous TiNbO 4 /C nanofibers (denoted as TNO/C) are synthesized via electro-spinning. Abundant oxygen vacancies and large specific surface area make the sample exudes high specific capacity and good rate performance. After optimizing the calcination temperature, it is found that the porous TiNbO 4 /C nanofibers at 700 °C (denoted as TNO/C-700) can deliver the specific discharge capacity of 250.4 mAh g −1 in K-ion half cell and demonstrate good cycle stability for 100 cycles in K-ion full cell in 100 mA g − 1 . Even in 5 A g − 1 , the discharge capacity of TNO/C-700 electrodes is still 116.7 mAh g − 1 at rate performance. Ex-situ XRD results show that this TNO/C-700 electrode is associated with pseudo-capacitive effect and insertion/de-insertion process. The TNO/C-700 electrode exhibits a high pseudo-capacitive contribution, which can reach to 85.0% at 3 mV s −1 . This novel high pseudo-capacitive contribution anode material provides more possibilities for the selection in KIBs.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
无机非金属材料
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Wenbin Wu,Ping Zhang,Siqi Chen,Xiaohong Liu,Guilin Feng,Meihua Zuo,Wangyan Xing,Bin Zhang,Weifeng Fan,Heng Zhang,Ping Zhang,Jie Zhang,Wei Xiang
O3 phase layered oxides are highly attractive cathode materials for sodium-ion batteries because of their high capacity and decent initial Coulombic efficiency. However, their rate capability and long cycling life are unsatisfactory due to the narrow Na + transfer channel and irreversible phase transitions of O3 phase during sodiation/desodiation process. Constructing O3/P2 multiphase structures has been proven to be an effective strategy to overcome these challenges. In this study, we synthesized bi-phasic structured O3/P2 Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 1- x Mn x O 2 ( x = 0.01, 0.02, 0.03, 0.04, 0.05) materials through Mn doping during sodiation process. Benefiting from surface P2 phase layer with the enhanced Na + transfer dynamics and high structural stability , the Na(Ni 2/9 Fe 1/3 Cu 1/9 Mn 1/3 ) 0.98 Mn 0.02 O 2 (NFCM-M2) cathode delivers a reversible capacity of 139.1 mA h g −1 at 0.1 C, and retains 71.4 % of its original capacity after 300 cycles at 1 C. Our work provides useful guidance for designing multiphase cathodes and offers new insights into the structure-performance correlation for sodium-ion cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Chenxi Zhang,Xueshuang Deng,Jianfeng Zheng,Xin Zhou,Jianhua Shi,Xiaohong Chen,Zhuo Sun,Sumei Huang
We report a simple and low-cost approach to enhance the longstanding stability of the perovskite solar cell (PSC) through the application of low-temperature grown SnO 2 nanorod (NR) arrays. SnO 2 NR arrays were fabricated by an aqueous synthesis method in the presence of hydrochloric acid and using thin compact SnO 2 as seeds. The influence of HCl concentration on the photovoltaic (PV) performance of the SnO 2 NR array based PSC device was investigated. The formed crystalline SnO 2 nanorods with square transversal-sections were oriented on the FTO facets in a well-defined and perpendicular fashion at an optimal HCl concentration. The optimized width and length for SnO 2 nanorods were 30 nm and 150 nm, respectively. Consequently, efficient and stable SnO 2 nanorod based perovskite devices were obtained with an average power conversion efficiency (PCE) of 16.57%. The SnO 2 nanorod array based PSCs demonstrated considerably better ultraviolet (UV) and ambient air stability than the planar SnO 2 and notably mesoporous TiO 2 solar cells. This paper provides a prospective scheme to grow high-quality three-dimensional SnO 2 nanorod arrays for highly stable and efficient PSCs.
研究领域:
材料科学
·
纳米科技
·
能源化学
·
光伏技术
·
半导体器件
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 15
·21459-21465
·
IF 4.527
Xianwei Su,Xiaojia Shang,Yusi Che,Shaolong Li,Jianxun Song,Jilin He
Homogenous ZrC x O y powders have been successfully synthesized by in-situ electro-reduction of solid ZrO 2 –C composite precursors in molten CaCl 2 . The effect of applied cell voltage and molar ratio of ZrO 2 to C on preparation of ZrC x O y were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO 2 is firstly converted to CaZrO 3 . The resulting CaZrO 3 is then reduced to ZrC x O y . The ZrC x O y formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO 2 to C: a higher cell voltage and lower molar ratio of the ZrO 2 to C are more preferable for the formation of ZrC x O y powder. Homogenous ZrC x O y powders with particle size of ~100 nm are synthesized by ZrO 2 /C starting elemental powders in CaCl 2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO 2 to carbon starting materials is 1:1.0.
研究领域:
材料科学
·
无机非金属材料
·
电化学合成
·
粉末冶金
·
固态化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）