CERAMICS INTERNATIONAL
·
2018
·Vol. 44
·期 7
·8710-8715
·
IF 3.057
Yang Chen,Chengji Deng,Chao Yu,Jun Ding,Hongxi Zhu
ZrN nanopowders were obtained by using ZrO 2 and Mg as the main raw materials in a molten salt environment and a high-purity nitrogen atmosphere. The effects of ZrO 2 / Mg mole ratio, nitriding temperature , and holding time on the synthesis of ZrN were investigated. ZrN was formed at 700 °C for 3 h. When the nitriding temperature increased to 1000 °C, pure phase ZrN was formed. The specific surface area of ZrN was 20.92 m 2 /g. When the temperature rose to 1100 °C, the resulting ZrN particles were finer; the average size of ZrN decreased from 71.60 to 49.65 nm. Further, an excessively long holding time led to evaporation of the molten salt, ZrO 2 , which was not fully nitrided. Finally, a possible formation mechanism of ZrN is proposed.
研究领域:
材料科学
·
无机化学
·
纳米材料
·
高温合成
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 21
·30039-30042
·
IF 4.527
Leihao Feng,Qiwei Hu,Li Lei,Lei Qi,Leilei Zhang,Meifang Pu,Zili kou,Fang Peng,Duanwei He,Yohei Kojima,Hiroaki Ohfuji,Tetsuo Irifune
High-hardness TaN compacts with a diameter and height of 6 mm were synthesized through the phase transformation of CoSn-type into WC-type TaN under experimental conditions of high temperature and high pressure . The Vickers hardness of WC-type TaN compacts obtained at the pressure of 5 GPa and the temperature of 1873 K is found to be ~21.5 ± 1.5 GPa with a load of 3 Kg, which is comparable to that of the pure tungsten carbide compact (~20 GPa) and higher than those of ultrahigh temperature ceramics ZrB 2 and HfB 2 under the same load. The high hardness of WC-type TaN compacts presented in this work is attributed to the deviatoric strain and well-bonded nanograins . The synthesized WC-type TaN compacts also possess a high oxidation temperature (1072 K). These results suggest that the WC-type TaN with high hardness and high thermal stability holds great promise for industrial applications.
研究领域:
材料科学
·
无机非金属材料
·
超硬材料
·
高温材料
·
固态化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 47
·期 5
·5918-5928
·
IF 3.83
Yu Zhao,Tianqi Zhang,Liaoyuan Chen,Tianbiao Yu,Jiayu Sun,Chuang Guan
In situ Ti(C, N), ring phase, and multi-phase enhanced Ni204-based alloy coating were prepared by adding various Ti/C/TiN ratios particles. The effects of the reinforcement phase on the microstructure, microhardness , tribological property, and microstructure characteristics at the interface between the coating and substrate were investigated. The results show that the coatings with a 5:1 mass fraction ratio of TiN/C exhibits the highest microhardness , which is 3.78 times higher than that of the original Ni204 coating. While, the coating with 21:7:2 mass fraction ratio of TiN/Ti/C exhibits the lowest friction coefficient , which is 4.44 times smaller than that of the original Ni204 coating. The addition of Ti and C particles promotes the precipitation of ring phase and carbides , reduces ceramic agglomeration, alleviates the floating of ceramic particles, and improves the bonding strength of reinforcement phases. Owing to the good mutual solubility among Fe, Ni, and, Cr elements, the diffusion happened at the interface between the coating and substrate.
研究领域:
材料科学
·
表面工程
·
金属学与金属工艺
·
机械工程
·
复合材料
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Xingchao Zhang,Ruoyu Zhang,Siying Niu,Jiming Zheng,Chongfeng Guo
The MoS 2 /g-C 3 N 4 heterojunction composite (marked as MoS 2 /g-C 3 N 4 -H) was successfully prepared via calcining the melamine coated MoS 2 nano-sphere, where the thin g-C 3 N 4 nano-sheets were tightly grown on the surface of MoS 2 nano-sphere to form MoS 2 inlaying in g-C 3 N 4 heterostructure. The detailed charge transfer mechanism was discussed by combining theoretical calculation and experiments, in which the intrinsic cause of photo-generated charge separation and transfer was determined as the directional built-in electric field driven by different Fermi levels of MoS 2 and g-C 3 N 4 . Comparatively, the enhanced photo-catalytic performance and stability of the sample were assessed by degrading the Rhodamine (RhB) and reducing the Dichromate (Cr 6+ ) solutions under the irradiation of the simulated sunlight, which could be attributed to the widened spectral absorption range and improved electron-hole separation rate. Based on above results, the photo-catalytic mechanism involving redox reactions was also clearly proposed.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Zhenlan Qin,Yanwei Zeng,Qianhui Hua,Qunjie Xu,Xixun Shen,Yulin Min
The preparation of the composite films on aluminum alloy 5052 (AA 5052) by the simple brush coating method in order to improve the corrosion resistance of aluminum alloy is the urgent need. However, some preparation methods, such as chemical vapor deposition, heat treatment, are relatively high cost and their preparation condition is very rigorous. In this paper, boron nitride and silane for boron nitride (h-BN)-dodecyl trimethoxysilane (DTMS)- (3-Aminopropyl) triethoxysilane (APTES) are used to improve corrosion resistance of AA 5052 with a simple and low-cost method. The corrosion resistance of the film has been characterized by electrochemical test in the 0.5 M H 2 SO 4 + 2 ppm HF acid solution. The results show that the protection efficiency of the h-BN-DTMS-APTES composite film reaches 99.97%, which greatly improves the corrosion resistance of the aluminum alloy 5052. When the sample is immersed into a 0.5 M H 2 SO 4 + 2 ppm HF aqueous solution for 120 h, the protection efficiency of the h-BN-DTMS-APTES composite film reaches 96.49% with good stability.
研究领域:
材料科学
·
表面工程
·
腐蚀与防护
·
纳米复合材料
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Yulong Yang,Jiao Feng,Shicui Zhu,Jinshu Zhou,Kejia Zhang,Xiaoyan Ma,Danial Gallagher,Andrea M. Dietrich
Nitrogenous disinfection by-products (N-DBPs) are more genotoxic and cytotoxic than the currently regulated carbonaceous DBPs (i.e., C-DBPs), and it has become a frontier issue of drinking water safety research. In this paper, the effect of granular activated carbon (GAC) on adsorption and its influencing factors was investigated for a typical N-DBP phenylacetonitrile, which is produced during chlorination of phenylalanine precursor during water treatment. The results showed that GAC had a high adsorption capacity (q max = 22.92 mg/g) for phenylacetonitrile, and the adsorption isotherm was fitted to the Langmuir isotherm model. Pseudo-second-order equation can well describe the behavior of phenylacetonitrile adsorption on activated carbon (R 2 > 0.990), and the adsorption rate constant k 2 = 0.7780–14.12 g/(mg h). Analysis of the influencing factors showed that higher phenylacetonitrile concentration improved the adsorption equilibrium capacity and the adsorption rate. Water temperature and pH had little effect on the capacity or rate of adsorption.
研究领域:
环境科学
·
水处理工程
·
毒理学
·
环境健康
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2016
·Vol. 31
·期 1
·157-163
·
IF 0.4
Liu Rongpeng,Wan Liqiang,Huang Farong,Du Lei
The reaction kinetics between diazide(4,4’-biphenyl dibenzyl azide) and different diynes (dipropargyl bisphenol A and 1,3-diethynylbenzene) were studied by means of differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy ( 1 H-NMR). DSC was adopted to analyze the reactions under bulk polymerization condition, while 1 H-NMR for solution reaction polymerization was conducted. The apparent activation energies ( E
α ) calculated by Kissinger’s method were 77.96, 81.24 kJ/mol, which were confirmed by Friedman’s method, and 65.45, 69.36 kJ/mol by 1 H-NMR for dispropargyl bisphenol A/4,4’-biphenyl dibenzyl azide and 1,3-diethynylbenzene/4,4’-biphenyl dibenzyl azide, respectively. The polymerizations between the diazide and diynes were first-order reactions based on calculation from both DSC and 1 H-NMR. The results showed that the reaction between dipropargyl bisphenol A and 4,4’-biphenyl dibenzyl azide was easier than that between 1,3-diethynylbenzene and 4,4’-biphenyl dibenzyl azide, verifying that the reactivity of aliphatic alkyne was higher than that of aromatic alkyne.
研究领域:
高分子化学
·
物理化学
·
材料科学
·
有机化学
·
反应动力学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 13
·20810-20818
·
IF 3.83
Mengjing Liu,Sun-Wai Chiang,Xiaodong Chu,Jia Li,Lin Gan,Yanbing He,Baohua Li,Feiyu Kang,Hongda Du
Herein, oriented boron nitride (BN)/alumina (Al 2 O 3 )/polydimethylsiloxane (PDMS) composites were obtained by filler orientation due to the shear-inducing effect via 3-D printing. The oriented BN platelets acted as a rapid highway for heat transfer in the matrix and resulted in a significant increase in the thermal conductivity along the orientation direction. Extra addition of spherical Al 2 O 3 enhanced the fillers networks and resulted in the dramatic growth of slurry viscosity. This, together with filler orientation induced the synergism and provided large increases in the thermal conductivity . A high orientation degree of 90.65% and in-plane thermal conductivity of 3.64 W/(m∙K) were realized in the composites with oriented 35 wt% BN and 30 wt% Al 2 O 3 hybrid fillers. We attributed the influence of filler orientation and hybrid fillers on the thermal conductivity to the decrease of thermal interface resistance of composites and proposed possible theoretical models for the thermal conductivity enhancement mechanisms.
研究领域:
材料科学
·
高分子化学
·
热管理材料
·
先进制造
·
复合材料工程
✓ 已验证
DOI
高影响因子
Energy Technology
·
2018
·Vol. 7
·期 5
·1800927
·
IF 3.175
Jiacong Wu,Chunmei Li,Wenli Zhang,Juan Han,Lei Wang,Shuhao Wang,Yun Wang
It is a huge challenge for exploiting new photocatalysts with low-cost cocatalysts in place of precious metals to realize high-efficiency H 2 production from water. Herein, a new photocatalyst with a high H 2 production activity is prepared via modification of bimetallic manganese cobalt phosphide (Mn 0.67 Co 1.33 P) nanodots on graphitic carbon nitride (g-C 3 N 4 ). Moreover, the largest H 2 production rate of 113.1 μmol h −1 is obtained over the Mn 0.67 Co 1.33 P/g-C 3 N 4 -5 sample, which is about 2.75 times than that of Pt/g-C 3 N 4 -5 (41.2 μmol h −1 ). The high-performance H 2 production suggests page a page down that the modification effect of Mn 0.67 Co 1.33 P nanodots improves the visible harvest ability and separation efficiency of charge carriers. A typical example to improve the photocatalytic H 2 production performance by fabricating heterostructures using bimetallic phosphide to modify graphitic carbon nitride is provided.
研究领域:
材料科学
·
光催化
·
能源化学
·
纳米材料
·
可持续能源
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·Vol. 43
·期 14
·7038-7045
·
IF 4.229
Rui Lu,Min Hu,Caili Xu,Yi Wang,Yun Zhang,Bin Xu,Daojiang Gao,Jian Bi,Guangyin Fan
Developing effective catalysts for hydrogen evolution from hydrolysis of ammonia borane (AB) is of great significance considering the useful applications of hydrogen. Herein, graphitic carbon nitride (g-C 3 N 4 ) prepared through the simply pyrolysis of urea was employed as a support for Rh nanoparticles (NPs) stabilization. The in-situ generated Rh NPs supported on g-C 3 N 4 with an average size of 3.1 nm were investigated as catalysts for hydrogen generation from the hydrolysis of AB under mild conditions. The Rh/g-C 3 N 4 catalyst exhibits a high turnover frequency of 969 mol H 2 · (min·mol Rh ) −1 and a low activation energy of 24.2 kJ/mol. The results of the kinetic studies show that the catalytic hydrolysis of AB over the Rh/g-C 3 N 4 catalyst is a zero-order reaction with the AB concentration and a first-order reaction with the Rh concentration. This work demonstrates that g-C 3 N 4 is a useful support to design and synthesis of effective Rh-based catalyst for hydrogen-based applications.
研究领域:
催化化学
·
能源材料
·
纳米催化
·
氢能源
·
反应动力学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2017
·
IF 2.354
Leyu Zhan,Yao Zhang,Xiangyang Zhuang,Hui Fang,Yunfeng Zhu,Xinli Guo,Jian Chen,Zengmei Wang,Liquan Li
The x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites were investigated on their lithium ionic conductivities . They maintained the original phase structures of orthorhombic LiBH 4 and hexagonal β-Li 3 N during ball milling according to the analyses by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Electrochemical impedance spectra (EIS) tests showed that LiBH 4 -Li 3 N composites lift the lithium ionic conductivities from that of bulk LiBH 4 by nearly 100 times at low temperature. LiBH 4 -Li 3 N offers 1.06 × 10 − 5 S cm − 1 of conductivity while bulk LiBH 4 possesses only 2.05 × 10 − 7 S cm − 1 at 323 K. Cyclic voltammetry (CV) tests indicated that the voltage window of composites could attain 3 V, which is much more stable than Li 3 N (< 1 V). No thermodynamic incident appears in DSC curves except for the orthorhombic-hexagonal transition endothermic peak of LiBH 4 in the x LiBH 4 -Li 3 N composites. It confirms the phases stabilities of the x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites before and after CV tests. In-situ solid state Nuclear Magnetic Resonance (NMR) tests on LiBH 4 -Li 3 N illustrated that the high conductivity in low temperature should not come from high-temperature phase of LiBH 4 . Therefore, the enhancement of lithium ionic mobility of the composite might be attributed to both Li 3 N and the interfaces between small crystallites where transmission electron microscope (TEM) morphology showed the appearance of amorphous grain boundary.
研究领域:
材料科学
·
固态离子学
·
能源化学
·
电化学
·
纳米材料
·
固体电解质
·
锂离子电池
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 27
·14278-14285
·
IF 8.867
Haibo Tang,Xinlong Tian,Junming Luo,Jianhuang Zeng,Yingwei Li,Huiyu Song,Shijun Liao
Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction (ORR) owing to their low electrical resistance and good corrosion resistance. In this paper, we describe the preparation of a Nb-based binary nitride material with a porous nanogrid morphology/structure. The catalyst exhibited good catalytic activity and high stability towards oxygen reduction. We also intensively investigated the effect that doping with a second transition metal had on the performance of the catalyst. We found that the ORR activity of NbN could be enhanced significantly by enriching the d electrons of Nb through doping with a second transition metal, and that doping with cobalt resulted in the best improvement. Our optimal catalyst, Nb0.95Co0.05N, had an ORR activity ∼4.6 times that of NbN (current density @ 0.6 V vs. the RHE). XPS results revealed that Co doping increased the proportion of Nb in a low-valence state, which may be one of the most important reasons for the enhanced performance. Another important reason is the high surface area resulting from the porous nanogrid morphology. As transition metal doping is an attractive way to enhance the activity of nitride catalysts, our work may provide an effective pathway to achieve this.
研究领域:
材料科学
·
电化学
·
纳米科技
·
催化化学
·
能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）