CATALYSIS TODAY
·
2017
·
IF 4.636
Nianjun Hou,Ping Li,Tianmu Lv,Tongtong Yao,Xueli Yao,Tian Gan,Lijun Fan,Pengzhi Mao,Yicheng Zhao,Yongdan Li
Sm 0.5 Ba 0.5 MnO 3-δ (SBMO) has been synthesized with the Pechini method and investigated as an anode material of solid oxide fuel cells with H 2 and methanol as fuels. A cubic perovskite structure is formed after reduction. The reduction process of SBMO is studied with X-ray photoelectron spectroscopy and temperature programmed reduction techniques. The electrical conductivities of an SBMO sample sintered at 950 °C are 1.15 and 0.10 S cm −1 at 850 °C in air and H 2 , respectively. A single cell with an SBMO anode layer and a 300-μm La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ electrolyte layer exhibits a maximum power density ( P max ) of about 150 mW cm −2 at 850 °C with H 2 as fuel. The electrical conductivity of the anode layer with methanol as fuel is improved by the moderate carbon deposition, and the P max increases to about 415 mW cm −2 . The cell fed with methanol also shows a promising stability.
研究领域:
材料科学
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能源化学
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电化学
·
无机非金属材料
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燃料电池技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Lingwei Lu,Meilin Lv,Gang Liu,Xiaoxiang Xu
Constituting solid solutions has been an appealing means to gain control over various physicochemical properties. In this work, we synthesized a series of SrTiO 3 -BiFeO 3 solid solutions and systematically explored their structural, optical and photocatalytic properties. Our results show that all solid solutions crystallize in a primitive cubic structure and their band gap values can be easily tuned by adjusting molar ratios between SrTiO 3 and BiFeO 3 . Photocatalytic hydrogen production under both full range and visible light irradiation is greatly improved after forming solid solutions. The highest hydrogen production rate obtained is ∼180 μmol/h under full range irradiation (λ ≥ 250 nm) and ∼4.2 μmol/h under visible light irradiation (λ ≥ 400 nm), corresponding to apparent quantum efficiency ∼2.28% and ∼0.10%, respectively. The activity is found to be strongly influenced by surface area and light absorption. Theoretical calculation suggests that Fe contributes to the formation of spin-polarized bands in the middle of original band gap and is responsible for the band gap reduction and visible light photocatalytic activity .
研究领域:
材料化学
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光催化
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能源材料
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无机固体化学
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半导体物理
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太阳能转化
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表面科学
✓ 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
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能源材料
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纳米催化
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氢能源
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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
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固态离子学
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能源化学
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电化学
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纳米材料
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固体电解质
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锂离子电池
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 110
·108791-108800
·
IF 3.289
Wei Zhou,Haiqian Zhao,Jihui Gao,Xiaoxiao Meng,Shaohua Wu,Yukun Qin
The Fenton system (Fe2+/H2O2) generates ·OH with a high oxidation potential. However, as reactants themselves, H2O2 and Fe2+ can act as ·OH initiators as well as ·OH scavengers, leading to the need for a high dosage of reactants and increased costs. As a mixing-sensitive reaction, the ·OH-related reaction kinetics (·OH with Fe2+, H2O2, and RhB) was determined from the reaction rates (which were a constant in this work) and stoichiometry, in which the latter could be regulated by an addition strategy of Fenton reagents. This suggests that ·OH competitive reactions could be controlled by applying a macrolevel addition strategy. Herein, the effects of different addition approaches of Fe2+ and H2O2 on ·OH competitive reactions were quantitatively and systematically studied by analyzing the removal of the model pollutant RhB. We found that without stirring, and compared with a one-time addition, once H2O2 or Fe2+ was added in a step-wise pattern (e.g., one drop by one drop, 2 times, or 4 times), a high concentration of H2O2 or Fe2+ existed in a localized place for a longer period, resulting in a lower proportion of ·OH reacting with RhB, which we ascribed to an enhanced reaction between Fe2+, H2O2, and ·OH. However, when H2O2 and Fe2+ were added from two close points without stirring, a larger proportion of ·OH was scavenged by H2O2 and Fe2+; while under stirring, even a one-time addition of H2O2 or Fe2+ could cause severe scavenging of ·OH. The results also revealed a linear relationship between the RhB removal percentage and wavelength blue-shifts. This study showed that microlevel ·OH competitive reactions could be controlled by applying a macrolevel addition strategy of Fenton reagents without the addition of external chemicals. The results suggest this methodology can also offer an approach to lower ·OH invalid consumption by regulating the addition strategy in bigger reactors.
研究领域:
环境化学
·
水处理技术
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高级氧化过程
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反应动力学
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污染控制化学
✓ 已验证
DOI
高影响因子
FLAVOUR AND FRAGRANCE JOURNAL
·
2012
·Vol. 27
·期 5
·378-385
·
IF 1.424
Zhangfu Zeng,Yanxiong Fang,Hongbing Ji
The reason for low encapsulation efficiency of vanillin compared to p -hydroxybenzaldehyde within β -cyclodextrin was investigated. Fourier transform infrared spectra proved intermolecular interaction between guest and β -cyclodextrin. UV–visible studies indicated that vanillin and p -hydroxybenzaldehyde form 1:1 inclusion complexes with β -cyclodextrin. Nuclear magnetic resonance and quantum computational methods gave the most favourable orientation in which the guest molecule (vanillin or p -hydroxybenzaldehyde) is totally sequestered in the hydrophobic cavity of the cyclodextrin with the phenolic end located near the primary hydroxyls of the β -cyclodextrin and the aldehyde group near the secondary hydroxyls with hydrogen bonding formation. Encapsulation efficiency of the β -cyclodextrin inclusion with vanillin is about 29% lower than that with p -hydroxybenzaldehyde. This result could be attributable to the effect that the side chain methoxy group weakened the guest/host non-covalent intermolecular interaction, specifically, hydrogen bond interaction. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
药物化学
·
超分子化学
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分析化学
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药剂学
·
分子识别
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计算化学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Qin Xu,Lijuan Cai,Huijie Zhao,Jiaqian Tang,Yuanyuan Shen,Xiaoya Hu,Haibo Zeng
An enzymatic procedure based on a catalase biosensor for the detection of forchlorfenuron (CPPU) has been reported in this work. Catalase was immobilized on boron nitride (BN) sheets dispersed in chitosan by adsorption. The immobilized catalase exhibited direct electron transfer character and excellent electrocatalytic activity towards H 2 O 2 reduction. After introducing CPPU into the H 2 O 2 containing phosphate buffer solution , the catalase-catalyzed H 2 O 2 reduction current decreased. By measuring the current decrease, CPPU can be determined in the range of 0.5–10.0 µM with the detection limit of 0.07 μM. The non-competitive inhibition behavior of CPPU towards catalase was verified by the Lineweaver–Burk plots. Long stability character has been ascribed to this biosensor. Possible use of this biosensor in flow systems is illustrated. The proposed biosensor has been successfully applied to CPPU determination in fruits samples with satisfactory results.
研究领域:
分析化学
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生物传感
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食品安全
·
酶学
·
纳米材料
·
电化学
·
药物残留检测
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 5
·3603-3612
·
IF 2.599
Wang Min,Han Xiuxun,Zhao Yun,Li Jiajia,Ju Peng,Hao Zhaomin
Nano-sized materials have attracted tremendous attentions because of their promising practical applications and theoretical values. The nano-sized materials are able to not only enhance the intrinsic properties of their bulk counterparts but also give birth to new promising properties. Herein, heterojunctions consisted of graphene oxide (GO) and three different MoS 2 nanostructures, including nanoflowers, nanoparticles, and quantum dots, were constructed and used as photocatalysts in water splitting. The electrochemical behavior and photocatalytic performance of MoS 2 /GO composites were found closely related to the particle size and morphology of MoS 2 . Compared to bulk MoS 2 /GO photocatalyst, nano-sized MoS 2 /GO heterostructures exhibited obviously enhanced performance in photocatalytic hydrogen generation. Benefitting from the surface effect and the quantum confinement in MoS 2 quantum dots, MoS 2 quantum dots/GO displayed the highest photocatalytic activities. This study indicates that the decrease in the dimension of MoS 2 can effectively increase the photocatalytic hydrogen evolution performance of MoS 2 /GO heterostructures, and thus suggests preferred strategy to design other HER photocatalysts based on MoS 2 .
研究领域:
材料科学
·
纳米科技
·
光催化
·
能源化学
·
半导体物理
·
表面科学
·
可持续能源
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xing-Liang Yin,Lei-Lei Li,Jian-Hua Jiang,Xin-Xin Du,Dong-Hui Pang,Jie Yang,Zhong-Jia Li,Yuan-Xu Wang,Xin-Yue Li,Da-Cheng Li,Jian-Min Dou
Photocatalytic H 2 evolution from water splitting offers an attractive scientific and technological method to address the energy and environmental crisis. In this study, noble-metal-free Zn 0.5 Cd 0.5 S@MoS 2 core@shell nanoheterostructures were elaborately designed and successfully synthesized. The visible-light-driven photocatalytic performance investigation shows that the Zn 0.5 Cd 0.5 S@MoS 2 exhibits a state-of-the-art H 2 evolution rate of 40.2 mmol g −1 h −1 far exceeding that of pristine Zn 0.5 Cd 0.5 S by more than 57 times. Moreover, thanks to the protection of MoS 2 shells, the Zn 0.5 Cd 0.5 S@MoS 2 can retain long-term stability in four-cycles of 24 h reactions. Furthermore, a tentative mechanism on H 2 generation was systematically investigated and proposed, which contributes to understand the enhanced photocatalytic activity of the Zn 0.5 Cd 0.5 S@MoS 2 heterostructures and may inspire the synthesis of other desirable catalytic systems.
研究领域:
材料科学
·
物理化学
·
能源化学
·
纳米催化
·
光化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Ao Hu,Xinhuan Lu,Dongming Cai,Haijun Pan,Run Jing,Qinghua Xia,Dan Zhou,Yongde Xia
N-doped porous carbons incorporating highly-dispersed non-noble metallic cobalt (Co) nanoparticle materials were synthesized by rapid pyrolysis of a zeolitic-type metal-organic framework (ZIF-9) and their structures, morphologies, topologies and relevant physical and chemical properties were fully measured by different characterization technologies. The resulting derived Co/CN materials were further evaluated as catalysts in nitrobenzene hydrogenation. It was found that Co/CN materials showed remarkbly catalytic activity and chemoselectivity for mild hydrogenation of nitrobenzene. Amongst the studied a series of Co/CN-x (pyrolyzed at x °C) materials, sample Co@CN-800 shows the most superior catalytic activity for hydrogenation of nitrobenzene. In particular, the catalytic conversion activity of Co@CN-800 is 100% with aniline being the sole product at 70 °C for 2 h, 27.5 times higher than that of cobalt powder (Co). It is believed that the large pore size, adsorption of nitroarenes substrate with high selectivity and strong interaction of Co nanoparticles with the doped N species can result in the high activity of Co@CN-800. This work therefore offers a cost-effective approach in developing highly efficient catalytic materials towards mild hydrogenation of nitrobenzene.
研究领域:
催化化学
·
材料科学
·
有机合成
·
纳米材料
·
环境化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
T. Chen,Y. Zhou,L. Luo,X. Wu,Z. Li,M. Fan,W. Zhao
This manuscript describes cost-effective synthesis of heteroatom self-doped activated biocarbons from sword bean shells (ACBS) by a simple two-step process of carbonization and activation using different weight ratios of KOH/chars. The results showing as-prepared samples at different weight ratios present prevailing characteristics with mainly micropores , surface area as high as 2838 m 2 g −1 and nitrogen content of 1.67 wt%. The specific surface area (S BET ) and micropore volume (V DR ) of the ACBS samples significantly contribute to hydrogen uptake, and at 77 K, these values can reach up to 2.63 and 5.74 wt% at 1 bar and 40 bar, respectively. In addition, the ACBSs exhibit a high specific capacity of 183 F g −1 at 2 mV s −1 and 211 F g −1 at 0.5 A g −1 from CV and GCD analysis in a three-electrode system. The button cell CR 2032 devices assembled by two solid-state symmetric electrodes from ACBSs also present a high energy density of 19.5 W h kg −1 at 10 A g −1 . These devices also demonstrate superior cycling stability and rate performance with capacitance retention of nearly 100% capacity after 5000 cycles at a current density of 1 A g −1 . These results suggest that the as-prepared nitrogen-doped porous carbon material has a promising potential for energy conversion and storage devices or for hydrogen adsorptions.
研究领域:
材料科学
·
能源化学
·
纳米材料
·
电化学
·
多孔材料
·
储能技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Xuedong Wei,Na Li,Xianming Zhang
It remains a huge challenge to develop non precious electrocatalysts with high activity to substitute commercial Pt catalysts for hydrogen evolution reactions (HER). Here, the C-Cu-DI and C-Cu materials with the copper based nanoporous carbon structures were synthesized by carbonizing MOF199 and DI-MOF199. The composite structure and HER electrocatalytic properties of the C-Cu-DI and C-Cu materials are studied. The results show that C-Cu-DI and C-Cu samples exhibit good catalytic activity. And C-Cu-DI sample through the addition of Dimethyl imidazole(DI) in the DI-MOF199 precursor has higher electrocatalytic activity than the C-Cu sample. The superior catalytic activity is attributed to the special composite structure of nanoscale deposition particles on the framework with plenty of nano pores and nano copper and few copper oxidation particles distributed or wrapped into the amorphous porous carbon phase. The nano copper and few copper oxidation particles in the C-Cu and C-Cu-DI catalysts maybe provide the more effective catalytic activity sites. The C-Cu-DI composite with large size spherical hollow deposition particles has higher conductivity, better BET surface area and reasonable micro-meso-macro porous distribution, so the overpotentials at the current density of 1 mA cm −2 and 10 mA cm −2 are respectively 270 mV and 390 mV vs. RHE. Although the HER activity has a big gap with commercial platinum catalyst, this study can provide an important experimental exploration for the design of copper based non noble metal/nano porous carbon composite HER electrocatalyst.
研究领域:
材料化学
·
电化学
·
纳米材料科学
·
能源催化
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）