MATERIALS LETTERS
·
2015
·
IF 2.489
Jingzhong Zhao,Weiqiang Xing,Yang Li,Kathy Lu
Oxygen-deficient anatase TiO 2 sheets with dominant (001) facets are becoming a hot research topic due to their promising high activity in heterogeneous reactions . In this work, a series of (001) facets dominated TiO 2 with distributed oxygen vacancies and Ti 3+ was prepared by a simple hydrothermal method with the TiB 2 as a precursor. The as-prepared powders were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV–visible diffuse reflectance spectroscopy (UV–vis). The results show that the particle size of as-prepared TiO 2 increases and its band gap narrows with the hydrothermal temperature increasing from 140 °C to 180 °C. Besides, oxygen vacancies and Ti 3+ are generated during the TiB 2 hydrolysis, which leads to new absorption spectrum in the visible light region. Photocatalytic test shows that sample prepared at 180 °C presents the highest degradation efficiency.
研究领域:
材料科学
·
光催化
·
纳米材料
·
表面化学
·
半导体材料
✓ 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
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纳米材料
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能源存储
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催化化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Chao Peng,Ping Wei,Xin Chen,Yongli Zhang,Feng Zhu,Yonghai Cao,Hongjuan Wang,Hao Yu,Feng Peng
2D MXenes have attracted extensive attentions owing to their anisotropy, high conductivity and other extraordinary properties. The popular preparation method of MXenes usually involves HF in high concentrations, which has seriously restricted their pervasive applications. In this work, a new hydrothermal route with low-toxicity etching agents (NaBF 4 , HCl) was used to synthesize Ti 3 C 2 MXene ( h- Ti 3 C 2 ). Compared with the Ti 3 C 2 prepared by the traditional HF etching method ( t- Ti 3 C 2 ), the h- Ti 3 C 2 has the higher c lattice parameter , larger interlayer distance and larger BET specific surface area, because of the slow release mechanism during the hydrothermal process. The hydrothermal etching method not only avoided the use of high-concentration HF, but also was more efficient to prepare Ti 3 C 2 flakes. Moreover, the hydrothermal etching route can be extended to other MXene materials, e.g. Nb 2 C. We demonstrated that the h -MXenes have better adsorption performance of methylene blue and methyl orange dyes. The hydrothermal etching route proposed in this study enabled the environmental benign and high efficiency exfoliation of MXenes, displaying the promise to facilely prepare 2D MXenes and paving a way to their widespread applications.
研究领域:
材料科学
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纳米材料
·
环境功能材料
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表面化学
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胶体与界面科学
✓ 已验证
DOI
高影响因子
IONICS
·
2016
·Vol. 23
·期 4
·985-996
·
IF 2.119
Sun Kanjun,Li Jindan,Peng Hui,Feng Enke,Ma Guofu,Lei Ziqiang
Nitrogen-doped porous activated carbons (N-PHACs) have been successfully synthesized using pomegranate husk as carbon precursor via ZnCl 2 -activation carbonization and subsequent urea-assisted hydrothermal nitrogen-doping method. The obtained N-PHACs possesses abundant mesoporous structure, high specific surface area (up to 1754.8 m 2 g −1 ), pore volume (1.05 cm 3 g −1 ), and nitrogen-doping content (4.51 wt%). Besides, the N-PHACs-based material showed a high specific capacitance of 254 F g −1 at a current density of 0.5 A g −1 and excellent rate performance (73% capacitance retention ratio even at 20 A g −1 ) in 2 M KOH aqueous electrolyte, which is attributed to the contribution of double-layer capacitance and pseudocapacitance. The assembled N-PHACs-based symmetric capacitor with a wide operating voltage range of 0–1.8 V exhibits a maximum energy density of 15.3 Wh kg −1 at a power density of 225 W kg −1 and superior cycle stability (only 6% loss after 5000 cycles) in 0.5 M Na 2 SO 4 aqueous electrolyte. These exciting results suggest that the novel N-doping porous carbon material prepared by a green and low-cost design strategy has a potential application as high-performance electrode materials for supercapacitors.
研究领域:
材料科学
·
电化学
·
纳米能源
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储能材料
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碳材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Yiping Sun,Houcai Dong,Kuan Wu,Xi Chen,Shaofei Wang,Wei Gu,Ziwei Hong,Min Liu,Yanbin Shen,Wei Lu
Surface coating is an efficient strategy to enhance the interfacial stability of the electrode. Graphene quantum dots (GQDs) have advantages of excellent dispersion in water, outstanding electron and ion conductivities and high specific surface area. In this work, GQDs were coated directly on the surface of LiCoO 2 particles (GQDs-LiCoO 2 ) through liquid phase method. Compared to bare LiCoO 2 , the cycling performance, rate capacity and thermo-stability of the GQDs-LiCoO 2 have been significantly improved in the voltage range of 3.04.5 V. GQDs-LiCoO 2 showed a much higher capacity retention than that of bare LiCoO 2 (82.8 % vs 46.1 %) after 100 cycles at 0.5 C. The excellent improvement of the GQDs-LiCoO 2 was mainly attributed to the formation of a uniform, stable, dense and well-conductive protective layer on the surface of LiCoO 2 particles by the surface coating of GQDs. The detailed analysis of the cycled electrodes reveals that the GQDs coating stabilizes the crystal structure of LiCoO 2 and suppresses undesirable interfacial side reactions between the cathode and electrolyte, leading to the improvement of battery performance.
研究领域:
材料科学
·
电化学
·
能源存储
·
锂离子电池
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界面工程
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2018
·Vol. 12
·期 3
·409-416
·
IF 2.643
Hao Meifeng,Xiao Mingshu,Qian Lihong,Miao Yuqing
A low-cost and high-activity catalyst for oxygen evolution reaction (OER) is the key to the water splitting technology for hydrogen generation. Here we report the use of three solvents, DMF, ethanol and glycol, in the solvothermal synthesis of three nano-catalysts, Co 3 (VO 4 ) 2 -I, Co 3 (VO 4 ) 2 -II, and Co 3 (VO 4 ) 2 -III, respectively. Transmission electron microscope shows Co 3 (VO 4 ) 2 -I, II, and III exist as ultrafine nanosheets, ultrathin nanofilms, and ultrafine nanosheet-comprised microspheres, respectively. These Co 3 (VO 4 ) 2 catalysts exhibit OER electrocatalysis, among which the Co 3 (VO 4 ) 2 -II shows the lowest onset overpotential of 310 mVand only requires a small overpotential of 330 mV to drive current density of 10 mA/cm 2 . Due to their high surface free energy, the ultrathin nanofilms of Co 3 (VO 4 ) 2 -II exhibits a good immobilization effect with the high electrocatalytic activity for OER.
研究领域:
材料科学
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电化学
·
纳米科技
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 74
·69966-69972
·
IF 3.289
Yu Guan,Leishan Shao,Dongyu Dong,Fei Wang,Yuliang Zhang,Yinghan Wang
Polymer composites exhibit very high strength but this is usually found to be at the expense of toughness, which greatly limits their application in many fields. Inspired by the hierarchical architectures in spider silk, we attempted to combine simultaneous high strength and toughness via a hydrogen bonding network. PVA composites with tannic acid (TA) molecules were fabricated by a green and easy-to-scale-up water casting method. The results showed that the hydrogen bonding crosslinking between PVA and TA has strong effect on the Tg, crystallinity, thermal stability and mechanical properties of PVA. In addition, the PVA composite films with 3 wt% TA exhibited, simultaneously, the best tensile strength and toughness, improving by 46% and 27% compared to the pure PVA, respectively.
研究领域:
高分子材料
·
生物医学工程
·
纳米复合材料
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生物启发设计
·
组织工程
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD SCIENCE
·
2023
·Vol. 88
·期 5
·1890-1904
·
IF 3.9
Xue Bai,Lihong Zhou,Yutong Wu,Luyi Xie
Small-leaved Kuding tea (SLKDT) obtained from Ligustrum robustum is a traditional tea substitute in southern China and has a range of physiological effects. However, the changes in its phytochemical composition after various heat treatments are not reported yet. Thus, the phytochemical composition and antioxidant activities of fresh leaves of SLKDT (LrF1) and SLKDT after high-temperature wet-heat treatment (LrF2) and wet- and dry-heat treatments (LrF3) were assessed using liquid chromatography–mass spectrometry, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and lipid peroxidation inhibition activity of LrF1 and LrF3 were investigated. The results indicated that the phytochemical composition of LrF1, LrF2, and LrF3 was significantly different. Overall, 258 and 83 differential constituents, respectively, were obtained in LrF1 versus LrF2 and LrF2 versus LrF3. The differential constituents mainly included amino acids and their derivatives, nucleosides, flavonoids, terpenoids, simple phenylpropanoids, and coumarins. After heat treatment, SLKDT exhibited obvious changes in sensory characteristics and physiological properties, which may be related to the changes in the levels of amino acids, linalool, beta-geraniol, myricetin, naringin, fraxetin, and isoacteoside. Moreover, the antioxidant activities significantly changed after heat treatment of SLKDT. Overall, our study demonstrated that heat treatment can alter the phytochemical composition of SLKDT, thus affecting its sensory properties and physiological properties. Practical Application This study preliminarily assessed the changes in the composition of small-leaved Kuding tea (SLKDT) after various heat treatments and revealed that the composition of SLKDT tea can be adjusted by various heat and temperature treatments.
研究领域:
植物化学
·
食品科学
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分析化学
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药理学
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茶叶加工
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2011
·
IF 1.795
Qinfu Zhao,Tianyi Wang,Jing Wang,Li Zheng,Tongying Jiang,Gang Cheng,Siling Wang
In order to improve the dissolution rate and increase the bioavailability of a poorly water-soluble drug, intended to be administered orally, the biocompatible and bioactive mesoporous hydroxyapatite (HA) was successfully synthesized. In the present study, mesoporous HA nanoparticles were produced using Pluronic block co-polymer F127 and cetyltrimethylammonium bromide (CTAB) as templates by the hydrothermal method. The obtained mesoporous HA was employed as a drug delivery carrier to investigate the drug storage/release properties using carvedilol (CAR) as a model drug. Characterizations of the raw CAR powder, mesoporous HA and CAR-loaded HA were carried out by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, N 2 adsorption/desorption, thermogravimetric analysis (TGA), and UV–VIS spectrophotometry. The results demonstrated that CAR was successfully incorporated into the mesoporous HA host. In vitro drug release studies showed that mesoporous HA had a high drug load efficiency and provided immediate release of CAR compared with micronized raw drug in simulated gastric fluid (pH 1.2) and intestinal fluid (pH 6.8). Consequently, mesoporous HA is a good candidate as a drug carrier for the oral delivery of poorly water-soluble drugs.
研究领域:
药剂学
·
生物材料
·
药物传递
·
纳米医学
·
药代动力学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Hongrui Jia,Weitong Zhu,Shuai Yang,Fei Li,Linghang Wang
<001> oriented x Bi(Mg 1/2 Ti 1/2 )O 3 -(0.7- x )Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 (BMT-PMN-PT) textured ceramics are successfully fabricated by the template grain growth method using BaTiO 3 platelets as template. BMT-PMN-PT textured ceramics with different BMT contents are studied in terms of crystal structure, microstructures, dielectric and ferroelectric properties, and electric field induced strain. The as-fabricated BMT-PMN-PT textured ceramics were found to have a strong orientation along <001> direction. The frequency dispersion of dielectric constant of BMT-PMN-PT textured ceramics increases gradually and its relaxability becomes stronger with increasing BMT content. A large electric-field induced strain (0.42 % at 4 kV/mm) is obtained in 0.25BMT-0.45PMN-0.3PT textured ceramics with Lotgering factor 0.94, which is about 83 % enhancement than that of the randomly oriented ceramics (0.23 % at 4 kV/mm). The strain of 0.25BMT-0.45PMN-0.3PT textured ceramics have a relatively high thermal stability, with a slight decrease from 0.42 % to 0.28 % in the temperature range of 20−100 °C. Our research suggests that 0.25BMT-0.45PMN-0.3PT textured ceramics have a greatly potential for actuator devices applications owing to its advantages of large electric field induced strain response.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
电介质材料
·
先进制造
✓ 已验证
DOI
高影响因子
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
·
2019
·Vol. 26
·期 3
·1009-1017
·
IF 2.135
Xinyu Wang,Thomas Andritsch,George Chen,Suvi Virtanen
In nanocomposites, different surface states of nanoparticles can potentially provide different interactions with the base polymer and in turn change the bulk properties. Aluminium nitride (AlN) nanoparticles were surface functionalised with three different silane coupling agents (SCAs) with varying organofunctional and hydrolysable groups. The effects of the filler surface chemistry on the resulting AlN/polypropylene (PP) nanocomposites were examined and compared with an unfilled reference system. It is observed that different organofunctional groups can provide different nucleating effects and the dispersion states of nanoparticles while the hydrolysable group is not the dominant factor. The dielectric spectroscopy results show the hydrolysable group of SCA will also result in a difference of the interphase since the trimethoxy silane treated systems show much higher imaginary permittivity than the triethoxy silane treated systems when the frequency is below 1 Hz. The grafted organofunctional layer on the particle surface can provide a significant improvement of the thermal conductivity of the composite materials, e.g. 15 % improvement in thermal conductivity was observed when adding 10 wt% methacrylate silanes treated nano-AlN into PP, while the untreated counterpart only has 5 % improvement.
研究领域:
高分子化学
·
材料科学
·
纳米技术
·
电介质物理
·
热传导材料
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2015
·Vol. 17
·期 11
·2376-2388
·
IF 4.034
Xiang-Sheng Zhai,Wen-Gang Zhu,Wei Xu,Ya-Jing Huang,Yue-Qing Zheng
Four new 3D uranyl complexes, [(UO2)2(H2O)(ipa)2]·9H2O (1), [(UO2)2(H2O)(nip)2]·H2O·Et3NH (2), [(UO2)2(H2O)(aip)2]·Et3NH (3) and [(UO2)(hip)]2·17H2O (4) (H2ipa = isophthalic acid, H2nip = 5-nitroisophthalic acid, H2aip = 5-aminoisophthalic acid, H2hip = 5-hydroxyisophthalic acid, Et3N = triethylamine), were hydrothermally synthesized. Structural analyses reveal that compounds 1–4 consist of pentagonal bipyramidal uranyl monomers bridged via acid inkers to form a structural motif, [(UO2)2L2], serving as the foundation of the 3D framework. Two structural motifs adopt different arrangement modes to connect to two types of chains. For 1–3, uranium atoms and carboxyl groups being from two types of chains respectively are coordinated to build similar 3D frameworks, while for 4, one type of chain links to the 3D architecture by the bond of the uranium atoms and –OH of the 5-hydroxyisophthalic acid ligand. The different guest molecules and structure assemblies displayed by the four compounds are a function of the variation of substituent groups of 5-X-1,3-benzenedicarboxylic acid (X = –H, –NO2, –NH2, –OH). Furthermore, the photocatalytic properties of 2 and 4 for degradation of rhodamine-B (RhB) upon xenon lamp irradiation have been examined. Elemental analysis, infrared spectroscopy, DRS and luminescence properties were also discussed.
研究领域:
无机化学
·
配位化学
·
材料科学
·
物理化学
·
环境化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）