CRYSTENGCOMM
·
2014
·Vol. 16
·期 37
·8910-8916
·
IF 3.858
Feng Ye,Hui Liu,Wenlai Huang,Jun Yang
Controlling the morphology of noble metal nanoparticles can be an effective way to produce nanomaterials with favourable properties. Herein, we report our study on the effects of diffusion rate and reaction kinetics on the morphology of a number of noble metal (Au, Ag, Pd, and Pt) nanoparticles. A glass reactor based on electrochemical reduction or photo-reduction has been designed to achieve control of diffusion and chemical reduction of the different noble metal precursors. The results show that the noble metal nanoparticles with flower-like, core–shell, or wheel-like morphologies could be obtained at a relatively high diffusion rate due to the presence of additional growth of metal precursors on the preformed metal nuclei, while at relatively low diffusion, the as-prepared noble metal nanoparticles are small and quasi-spherical due to the relatively fast reduction of metal precursors. The experimental observations are also confirmed qualitatively by kinetic Monte Carlo (kMC) simulations. Since diffusion and reaction kinetics are universal and key factors in the synthesis of nanomaterials, the findings in this work might provide an effective way to manipulate the morphology of nanomaterials for a given application.
研究领域:
纳米材料科学
·
物理化学
·
材料合成
·
胶体与界面化学
·
计算材料学
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD PROTECTION
·
2018
·Vol. 81
·期 10
·1643-1650
·
IF 1.51
Huqing Yang,Xia Li,Guoquan Lu
Because of high water loss and rot observed in postharvest sweet potato ( Ipomoea batatas (L.) Lam.) roots, a carnauba wax (CW)–based nanoemulsion without or with glycerol monolaurate (CW-GML) was developed by a high-energy emulsification approach. The effects of the two coatings on decay, respiration rate, weight loss, surface color, total soluble sugar, and starch content as well as the sensory quality of sweet potato roots were investigated during storage at 20°C for 50 days. Compared with the control treatment (water) and CW coating alone, CW-GML coating exhibited higher emulsion stability and antifungal activity, and treatment resulted in a uniform and continuous coating on roots. The CW-GML and CW coatings both effectively reduced root weight loss and respiration rate and inhibited decay incidence compared with control roots during storage. The CW-GML coating showed markedly stronger inhibition of root rot than the CW coating. Both the CW-GML and CW coatings promoted an increase in root sweetness but did not negatively impact perceived flavor. The overall results demonstrate that the CW-GML coating holds great promise as an effective postharvest technology to preserve food quality and extend shelf life of sweet potato roots.
研究领域:
食品科学
·
采后生物学
·
农产品贮藏
·
食品保鲜技术
·
应用植物学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Jing Jiang,Jiayi Zhang,Baihao Wu,Sheng Tu
The regulation of the metal-support interaction in heterogeneous catalysts can promote the activation of reactants, which is beneficial for the hydrolytic dehydrogenation reaction. Herein, the hydrolytic dehydrogenation of dimethylamine borane (DMAB) is systematically studied on the oxygen vacancy (O v ) enriched Pt-Co 3 O 4 heterogeneous catalyst with the metal-support interaction. It is found that the metallic Pt site facilitates the adsorption of DMAB molecules and the O v on Co 3 O 4 support as an electron-rich center cooperates with the adjacent Pt site to dissociate water molecules. The in situ Raman and attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy reveal the effective activation and cleavage of the O-H in water and the B-H in DMAB over the Pt-Co 3 O 4 catalyst. The optimal Pt-Co 3 O 4 catalyst exhibits the extraordinary activity for the catalytic hydrolysis of DMAB at 303 K, delivering a high specific hydrogen generation rate (64063 mL min −1 g pt −1 ) and a competitive turnover frequency (TOF, 23880 mol H2 mol Pt −1 h −1 ). This performance outperforms most of the reported heterogeneous catalysts for DMAB dehydrogenation . More importantly, the Pt-Co 3 O 4 catalyst achieves the desirable on-demand hydrogen production by using special chemical switches. This finding provides the fundamental understanding of metal-oxide systems with the collaborative interfacial catalysis for boosting DMAB dehydrogenation .
研究领域:
催化化学
·
纳米材料科学
·
能源化学
·
表面科学
·
多相催化
·
氢能存储与释放
✓ 已验证
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Chong Chen,Jiacan Shao,Shaojie Qu,Li Xie,Wenjian Jiang,Keying Zhang,Xin Zhuo,Hongwei Shi,Hongyan Wang,Li Sun,Li Zhang,Guang Zhu
Hollow carbon nanosheets with predominant mesopores have been demonstrated as a promising electrode material for supercapacitor , but their low specific surface area with relatively low micropore proportion limits their specific capacitance and energy density . Herein, we develop a novel extrusion plant microtube strategy to synthesize micron-sized nitrogen-doped hollow porous carbon nanosheets (MNHPCS) from dandelion fluff having the specific natural thin-wall and hollow tubular bundled structure through high-pressure extrusion, carbonization and KOH activation. The optimized MNHPCS displays strutted bilayer nanosheet structure, large SSA of 1593 m 2 g −1 , high micoporosity of 71.2 % and high heteroatom content (5.2 at.% for N, 7.0 at.% for O). Importantly, MNHPCS prepared by the new technique overcomes the drawbacks of hollow carbon nanosheets and presents an excellent capacitance of 378 F g −1 at 0.5 A g −1 and rate capability of 57 % at 80 A g −1 in 6 M KOH. Furthermore, the energy density of MNHPCS//MNHPCS based supercapacitor in EMIMBF 4 can reach up to 84 Wh kg −1 . Most importantly, MNHPCS can be easily achieved from various plant wastes having hollow tubular structure, which would provide a clearly method on selecting plant precursors for producing hollow porous carbon nanosheets applied on supercapacitors.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Jing Jiang,Wei Wei,Zhen Ren,Yang Luo,Xinzhi Wang,Ying Xu,Mingming Chang,Lunhong Ai
Developing efficient catalysts for the dehydrogenation of ammonia borane (AB) is important for the safe storage and controlled release of hydrogen, but it is a challenging task. In this study, we designed a robust Ru-Co 3 O 4 catalyst using the Mott-Schottky effect to induce favorable charge rearrangement. The self-created electron-rich Co 3 O 4 and electron-deficient Ru sites at heterointerfaces are indispensable for the activation of the B-H bond in NH 3 BH 3 and the O H bond in H 2 O, respectively. The synergistic electronic interaction between the electron-rich Co 3 O 4 and electron-deficient Ru sites at the heterointerfaces resulted in an optimal Ru-Co 3 O 4 heterostructure that exhibited outstanding catalytic activity for the hydrolysis of AB in the presence of NaOH. The heterostructure had an extremely high hydrogen generation rate (HGR) of 12238 mL min −1 g cat -1 and an expected high turnover frequency (TOF) of 755 mol H2 mol Ru -1 min −1 at 298 K. The activation energy needed for the hydrolysis was low (36.65 kJ mol −1 ). This study opens up a new avenue for the rational design of high-performance catalysts for AB dehydrogenation based on the Mott-Schottky effect.
研究领域:
催化化学
·
能源材料
·
纳米材料科学
·
表面科学
·
氢能源技术
✓ 已验证
DOI
高影响因子
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
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
热分析
·
聚合物结晶
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）