JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2014
·Vol. 119
·期 1
·205-212
·
IF 2.206
Yang Ting,Chen Liping,Chen Wanghua,Zhou Yishan,Gao Haisu,Zhong Tingting
2-Ethylhexyl nitrate (EHN) is an important material, which is produced by concentrated HNO 3 –H 2 SO 4 nitration process. But EHN is not a stable material, especially mixed with acids. To analyze the stability of EHN with concentrated acid under serious condition, four samples (pure EHN, concentrated sulfuric acid with EHN, concentrated nitric acid with EHN, and mixed acid with EHN) and three acids (sulfuric acid, nitric acid, and mixed acid) were measured by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) in this paper. The results indicated that concentrated sulfuric acid, concentrated nitric acid, and mixed acid all could decrease the onset decomposition temperature of EHN, especially concentrated sulfuric acid. DSC results also showed that the heat of EHN decomposition with nitric acid is larger than other samples. Based on ARC data, the kinetic parameters and T
D24 (temperature at which TMR
ad is 24 h) were calculated. The activation energy and T
D24 of the EHN with acids, especially with concentrate sulfuric acid, were much lower than the pure EHN. It can be concluded that acids could decrease the stability of EHN and that is an important reason for frequent accidents.
研究领域:
物理化学
·
安全工程
·
材料化学
·
热分析
·
危险品管理
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2011
·Vol. 22
·期 12
·1497-1500
·
IF 0.775
Xiao Zheng Lan,Hai Rong Pei,Chuan Xian Cheng
Phase behavior of binary system of bromobenzene–chlorobenzene (C 6 H 5 Br–C 6 H 5 Cl) confined in SBA-15 and MCM-41 (pore diameter 8 nm, 3.8 nm, respectively) has been investigated by means of differential scanning calorimetry (DSC). Phase diagram of C 6 H 5 Br–C 6 H 5 Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state, the same phase behavior as the bulk system. However, the phase diagram comprises only one boundary line, which is shifted down 22–36 K with respect to the bulk system. C 6 H 5 Br, C 6 H 5 Cl or the mixture within nanopores of MCM-41 is nonfreezing. The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.
研究领域:
物理化学
·
材料科学
·
纳米科技
·
热力学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·Vol. 45
·期 3
·1466-1476
·
IF 4.084
Yuelong Xu,Xiaoxi Dong,Junfeng Miao,Shasha Wang,Zhan Liu,Zuozhao Zhai,Lihui Zhang,Zhenfa Liu
Carbon nanomaterials that are electrochemically bifunctional and active in supercapacitor and hydrogen-evolution-reaction (HER) applications have attracted recent research attention. We have prepared porous carbon spheres - doped Ni, Co - alloys by using a hydrothermal method with melamine and pectin as precursors and with the addition of nickel nitrate and cobalt nitrate. The corresponding materials exhibit good electrochemical performance and excellent electrocatalytic activity for HER. The overpotential (OP) of the as-prepared materials can achieve 240 mV keeping a Tafel slope (TS) of 55 mV dec −1 at 10 mA cm −2 in an acid (0.5 M H 2 SO 4 ) solution. The corresponding samples maintain stability after 24 h and 5000 cycles in the chronovoltage and cyclic voltammetry methods, respectively. When the as-prepared materials are oxidized by 30% H 2 O 2 for 12 h, the corresponding as-prepared oxidation samples exhibit excellent electrochemical performance in a supercapacitor application. The specific capacitance (SC) of the as-obtained materials reaches 312 F g −1 at 1 A g −1 with decent rate capability and cyclic stability. This work provides new applications for bifunctional electrochemically active materials.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
催化化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Huan Zhou,Ying Yang,Mengmeng Yang,Wenjie Wang,Yaping Bi
Mesoporous hydroxyapatite is widely applied in biomedical and environmental fields due to its high surface area and adsorption capacity. In current work a one-step hydrothermal method to synthesize mesoporous HA was developed with the assistance of a cost-effective template vitamin C. It was observed the pore size and morphology of hydrothermally synthesized HA were correlated to applied solution composition. A combination of calcium hydroxide, orthophosphate, and vitamin C can finally result in mesoporous rod-like HA nanoparticles with surface area of 88 m 2 .g −1 and pore size of 15.7 nm on average. The mesoporous HA exhibited enhanced adsorption of model drug doxorubicin in comparison to conventionally synthesized HA as expected. Consequently, this work provides new pathway to prepare mesoporous HA with advantages of economy and convenience.
研究领域:
生物材料学
·
纳米医学
·
药剂学
·
环境科学
·
生物无机化学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2017
·
IF 2.238
Jianjian Sun,Bijun Fang,Shuai Zhang,Zhihui Chen,Jianning Ding,Xiangyong Zhao,Haosu Luo
Er 3+ -doped Na 0.5 Bi 0.5 TiO 3 (Er-doped NBT) ceramics were prepared via a hydrothermal method . High sintering active Er-doped NBT nano cubic particles with perovskite structure were synthesized at hydrothermal condition of 200 °C for 24 h in 12 M NaOH solution, which were self-assembled via in situ crystallization mechanism by the initially as-grown nanowires. The Er-doped NBT ceramics sintered at 1100 °C for 2 h exhibit pure rhombohedral perovskite structure, high densification and rather homogenous microstructure morphology. Under 488 nm light excitation , the strong green emission peaks centering at 530 nm and 550 nm and the weak red emission peaks locating at 665 nm and 735 nm are excited, which can be attributed to the 2 H 11/2 , 4 S 3/2 , 4 F 9/2 and 4 I 9/2 → 4 I 15/2 transitions, respectively. The maximum emission intensity is obtained when the Er doping content reaches 1.0 mol%. A strong upconversion emission peak centering around 550 nm in green light range is excited under 800 nm light excitation, which is correlated with the 4 S 3/2 → 4 I 15/2 transition.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
光电子学
·
固体化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2010
·Vol. 257
·期 9
·3920-3923
·
IF 1.616
Hongxu Guo,Jianhua Chen,Wen Weng,Shunxing Li
A visible light-driven photocatalyst, C-doped Zn 3 (OH) 2 V 2 O 7 , prepared by a hydrothermal method was studied. The as-prepared catalyst was characterized by SEM, XRD , DRS, and XPS , and exhibited efficient photocatalytic activity in the degradation of methylene blue (MB) under visible-light irradiation. Besides decoloring, the decomposition of MB was also observed, further demonstrating the performance of the photocatalyst. The carbon existing on the surface of Zn 3 (OH) 2 V 2 O 7 nanorods was free and in carbide form. Dye degradation followed first-order kinetics, and was explained on the basis of the Langmuir–Hinshelwood mechanism.
研究领域:
材料化学
·
光催化
·
纳米材料
·
环境化学
·
无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2014
·Vol. 32
·期 8
·686-690
·
IF 1.342
LIU Lisha,CHEN Haohong,LIU Biqiu,ZHANG Hui,TANG Bin,FENG Xianjuan,SUN Zhijia,ZHAO Jingtai
To explore novel nano-scintillator with a controllable architecture, pure and Eu 3+ doped lutetium oxyfluoride (Lu 7 O 6 F 9 ) powder were synthesized by combining mild hydrothermal method and solid state calcination approach. The products were all pure orthorhombic Vernier phase demonstrated by X-ray powder diffraction (XRD). The detailed crystal structure was also studied by Reitveld refinement. Lath-like microcrys tals composed of nanoparticles with unique hollow tube of the products were supported by the images of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Excited by X-ray with W as the target, the pure product showed intense broad emission with the peak at about 400 nm suitable for modern photoelectric multiplier tube (PMT), while the Eu 3+ doped sample transferred the incident energy to Eu 3+ ions and gave strong 5 D 0 → 7 F j ( j =0, 1, 2 and 4) emission, which fitted for imaging and labeling measurements. From the luminescent properties, both pure and Eu 3+ -doped products are potential excellent scintillator for X-ray imaging and other high energy detectors, and the pure product is also a good host candidate for rare earth doping.
研究领域:
材料科学
·
无机化学
·
发光材料
·
纳米医学
·
生物成像
·
辐射探测
✓ 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
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 23
·19614-19619
·
IF 2.324
Hu Yiwei,Chen Xinhang,Ren Xiaohui,Huang Zongyu,Qi Xiang,Zhong Jianxin
Tin disulfide (SnS 2 ) has been attracted intensive attention in the field of photoelectric conversion due to its appropriate band gap and glorious electronic mobility. The hexagon SnS 2 nanosheets has been successfully integrated through a facile one-pot hydrothermal method. SEM images, Raman spectra, atomic force microscope and X-ray diffraction patterns are measured to carry out to investigate the morphologies and microstructures of SnS 2 nanosheetsm, confirming a good crystallized SnS 2 . Then, the photochemical activity of as-prepared SnS 2 nanosheets were tested in the electrolyte of Na 2 SO 4 . Photoelectrochemical tests demonstrate that the photocurrent density of as-prepared hexagon SnS 2 nanosheets (1.66 µA/cm 2 at a light intensity of 140 mW/cm 2 ) is hugely increased with increasing light intensity. Furthermore, after 50 cycles, the photocurrent density does not change significantly, indicating that the as-prepared SnS 2 nanosheets possesses superior stabilities. The outstanding photocatalytic performances of SnS 2 nanosheets are not only resulted from its huge specific surface area, which can harvest more light and provide more active sites, but also attributed to its superior charge mobility, which can facilitate the separation photogenerated electron–hole pairs and the charge transfer between SnS 2 nanosheets and the electrode. The most important is that our work reveals the hexagonal SnS 2 nanosheets not only possess superior photoelectrochemical properties, but also have great potential applications in energy conversion and photodetector fields.
研究领域:
材料科学
·
光催化
·
能源转换
·
纳米材料
·
光电化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 45
·17328-17337
·
IF 4.569
Yan Zhu,Hongmei Qing,Wenbo Dong,Mingrong Dong,Tao Shen,Jian Cui
Copper zinc tin sulfide (Cu2ZnSnS4, CZTS) is attracting interest in photovoltaic applications due to its proper band gap, low cost and low toxicity. It has been found that two phases can be fabricated, i.e. kesterite and wurtzite CZTS structures. Though kesterite CZTS is proven to be thermodynamically stable, the free energy difference between kesterite and wurtzite CZTS is rather small. So, wurtzite CZTS can also stably exist under ambient conditions. Controlling the phase formation can expand the dimensions to optimize the performance of applications based on CZTS. In this study, we found that phase control can be achieved by simply using a mixed solvent of ethylene glycol and triethylenetetramine (TETA) in a two-stage heating process. It is found that the incorporation of the reductive solvent of TETA during the 1st heating process converts the phase of the precipitates from CuS (TETA poor) to Cu7S4 (TETA rich). In the subsequent 2nd heating stage, the phase of the final products is determined to be kesterite CZTS originating from CuS and wurtzite CZTS from Cu7S4, respectively. Thus, the key to control the phases of the final products is to control the chemical environment of Cu under Cu1+-rich or Cu2+-rich conditions in the fabrication process, which corresponds to the phase of the final products of wurtzite CZTS or kesterite CZTS, respectively. This summarized principle can not only be used to explain the previous versatile experimental results but also to guide the controlled synthesis of various phases of CZTS and CZTS-like materials in applications.
研究领域:
材料科学
·
无机化学
·
半导体材料
·
纳米科技
·
光伏材料
✓ 已验证
DOI
高影响因子
Nano Energy
·
2014
·
IF 10.211
Xiaolei Jiang,Huayun Xu,Jing Liu,Jian Yang,Hongzhi Mao,Yitai Qian
Hierarchical mesoporous Li 2 Mn 0.5 Fe 0.5 SiO 4 consisted of nanoparticles or nanoplates has been successfully synthesized for the first time by a hydrothermal method . Their carbon-coated composites are obtained by a heat treatment in the presence of citric acid. These composites were characterized by powder X-ray diffractometry, scanning and transmission electron microscopy , Raman spectroscopy , and thermogravimetric analysis . The lithium storage capacity and cycling performance of the optimized Li 2 Mn 0.5 Fe 0.5 SiO 4 /C composite are greatly enhanced when tested as a cathode material in lithium-ion batteries (LIBs). It exhibits a discharge capacity of 125 mAh g −1 after 60 cycles at a rate of 0.1 C. This superior electrochemical property could be ascribed to high purity and mesoporous structure of Li 2 Mn 0.5 Fe 0.5 SiO 4 , which greatly enhances the electronic conductivity as well as the diffusion coefficient of lithium ions .
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
固体化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2017
·
IF 2.865
Yanfeng Wang,Wei Chen,Xiao Chen,Huajun Feng,Dongsheng Shen,Bin Huang,Yufeng Jia,Yuyang Zhou,Yuxiang Liang
CdS/MoS 2 , an extremely efficient photocatalyst , has been extensively used in hydrogen photoproduction and pollutant degradation . CdS/MoS 2 can be synthesized by a facile one-step hydrothermal process. However, the effect of the sulfur source on the synthesis of CdS/MoS 2 via one-step hydrothermal methods has seldom been investigated. We report herein a series of one-step hydrothermal preparations of CdS/MoS 2 using three different sulfur sources: thioacetamide, l -cysteine, and thiourea . The results revealed that the sulfur source strongly affected the crystallization, morphology, elemental composition and ultraviolet (UV)–visible-light-absorption ability of the CdS/MoS 2 . Among the investigated sulfur sources, thioacetamide provided the highest visible-light absorption ability for CdS/MoS 2 , with the smallest average particle size and largest surface area, resulting in the highest efficiency in Methylene Blue (MB) degradation. The photocatalytic activity of CdS/MoS 2 synthesized from the three sulfur sources can be arranged in the following order: thioacetamide > l -cysteine > thiourea . The reaction rate constants ( k ) for thioacetamide, l -cysteine, and thiourea were estimated to be 0.0197, 0.0140, and 0.0084 min −1 , respectively. However, thioacetamide may be limited in practical application in terms of its price and toxicity, while l -cysteine is relatively economical, less toxic and exhibited good photocatalytic degradation performance toward MB.
研究领域:
材料科学
·
环境化学
·
纳米催化
·
光催化
·
无机功能材料
·
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）