搜索到2031篇“ KEPLERATE“的相关文章
Keplerate polyoxomolybdate nanoball mediated controllable preparation of metal-doped molybdenum disulfide for electrocatalytic hydrogen evolution in acidic and alkaline media
2024年
Rationally designed novel cost-effective hydrogen evolution reaction(HER)electrocatalysts with controlled surface composition and advanced structural superiority is extremely critical to optimize the HER performance.Polyoxometalates(POMs)with structural diversity and adjustable element compositions represent a promising precursor for rational design and preparation of HER electrocatalysts.Herein,a series of transition metal-doped MoS_(2)materials with different surface engineered structures(Fe,Cr,V doping and S vacancies)(M-MoS_(2)/CC,M=Fe,Cr and V)were fabricated by a simple hydrothermalvulcanization strategy using Keplerate polyoxomolybdate nanoball({Mo_(72)Fe_(30)},{Mo_(72)Cr_(30)},{Mo_(72)V_(30)},{Mo_(132)})as precursors.The enlarged interlayer spacing as well as the integration of homogeneous transition metal doping and abundant sulfur vacancies endows prepared M-MoS_(2)/CC with superior HER electrocatalytic performance and excellent long-term working stability in both acidic and alkaline media.The optimized Fe-MoS_(2)/CC afford current densities of 10 and 50 mA/cm^(2)at overpotentials of 188/272 mV and 194/394 mV in 0.5 mol/L H_(2)SO_(4)and 1.0 mol/L KOH aqueous solution,respectively,outperforming most of reported typical transition metal sulfide-based catalysts.This work represents an important breakthrough for POMs-mediated highly efficient transition metal sulfide-based HER electrocatalysts with wide range pH activity and may provide new options for the rational design of promising HER electrocatalysts and beyond.
Ping WangTing WangMing XuZe GaoHongyu LiBowen LiYuqi WangChaoqun QuMing Feng
关键词:POLYOXOMETALATEELECTROCATALYTIC
Molecular-scale co-assembly membranes derived from keplerate cluster:carbonic anhydrase-mimicking nanocapsules for enhanced CO_(2)/N_(2)separation
2024年
The development of CO_(2)separation membranes with high permeability and high selectivity,as well as ultra-thin selective layers,has always been challenging.Herein,a molecular-scaled co-assembly strategy is employed to fabricate the Pebax-Mo_(132)(Pebax=polyether-block-amide copolymer;Mo_(132)=(NH_(4))_(42)[Mo_(72)^(Ⅵ)Mo_(60)^(Ⅴ)O_(372)(CH_(3)COO)_(30)(H_(2)O)_(72)])membranes.The optimal selfstanding membrane,Pebax-Mo_(132)-5%,shows a CO_(2)permeability of~384 Barrer and an ultra-high ideal CO_(2)/N_(2)selectivity of~244,outperforming most membranes reported in the literature.The CO_(2)permeability and ideal CO_(2)/N_(2)selectivity are increased by 70%and 367%,respectively,compared with the pristine Pebax membrane.A thin-film composite membrane prepared by spin-coating technique on a support membrane with gutter layers also exhibits a CO_(2)permeance of 838 GPU and a CO_(2)/N_(2)selectivity of 136.Such excellent performance can be attributed to the following reasons:(1)strong hydrogen bonding interactions between{Mo_(132)}clusters and Pebax confer excellent interfacial compatibility to the mixed matrix membranes;(2)incorporation of hollow{Mo_(132)}clusters into the Pebax molecular chain decreases the crystallinity of Pebax,and thereby accelerates the chain dynamics and increases the free volume of the membrane;(3)in situ diffuse reflectance infrared Fouriertransform spectroscopy demonstrates that the{Mo_(132)}clusters can effectively catalyze the hydration reaction of CO_(2)and promote the transport of CO_(2);(4)furthermore,the 0.35 nm pores of the crown ether-type{Mo_(9)O_(9)}allow the accurate size sieving of CO_(2)(0.33 nm)and N_(2)(0.36 nm)molecules.
Wan-Lei ZhaoHongqiang LiRuoxuan ZhengYixin YangWei ChenYu-Fei Song
Keplerate型聚氧钼酸盐用于净化水生环境的用途
本发明涉及通用结构Mo<Sub>72</Sub>M<Sub>30</Sub>的Keplerate型聚氧钼酸盐用于净化水介质(水)中的无机和有机污染物的用途,其中M选自由Fe、Cr、V或Mo<Sub>2</Sub>组成的群...
马提亚·德里斯莱因哈德·肖马克加赖·苏梅纳特马丁·格罗斯阿米特瓦·阿查利亚迈克尔·施瓦策普拉桑特·梅内塞斯
Keplerate型聚氧钼酸盐用于净化水生环境的用途
本发明涉及通用结构Mo<Sub>72</Sub>M<Sub>30</Sub>的Keplerate型聚氧钼酸盐用于净化水介质(水)中的无机和有机污染物的用途,其中M选自由Fe、Cr、V或Mo<Sub>2</Sub>组成的群...
马提亚·德里斯莱因哈德·肖马克加赖·苏梅纳特马丁·格罗斯阿米特瓦·阿查利亚迈克尔·施瓦策普拉桑特·梅内塞斯
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Keplerate型多酸基纳米材料的制备及其电化学性质研究
近几十年来,随着能源需求的快速增长和化石燃料储量的日益衰竭,寻找环境友好型能量转换装置和开发高效清洁能源成为了科研工作者的当务之急。多金属氧酸盐(多酸)是一类由丰产元素和环境友好型金属组成的分子金属-氧簇,其独特的结构特...
董一娜
关键词:纳米复合材料超级电容器
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Keplerate型多酸-卟啉-锌铝水滑石复合薄膜的制备及其三阶非线性光学性质
多金属氧酸盐(POMs)是由前过渡金属离子通过氧连接而形成的一类多金属氧簇化合物。其中, Keplerate型Mo-O基多金属氧酸盐离子由于其特殊的结构在强光下容易发生极化作用,产生较好的非线性响应,在非线性光学领域有潜...
任海洲
关键词:多金属氧酸盐卟啉水滑石三阶非线性光学性质
Third-order Optical Nonlinearities of a Series of Compounds Derived from a Keplerate Type Molybdenum-oxide-based Polyoxometalate
2014年
Abstract By reacting the unique Keplerate type molybdenum-oxide based polyoxometalate (NH4)42·[MoI320372·(CH3COO)30(H2O)y2]·ca.300H2·ca. 10CH3COONH4(1) with tetramethylammonium bromide, a new derivative (NH4)26[TMA]16{MoI32O372(H2O)72(CH3COO)30}·ca.7NH4CH3COO·ca.189H2O(2, TMA=tetramethylammonium) was prepared. Compound 2 was characterized by Fourier transform infrared spectroscopy(FTIR), UV-Vis, elemental and thermogravimetric analyses. By the well-established Z-scan technique, investigations on the nonlinear opti- cal(NLO) properties of the series of compounds derived from the Keplerate type molybdenum-oxide-based poly- oxometalate, namely, the newly prepared compound 2, the three previously reported compounds, included compound 1, (NH4hs(TBA)24{Mo132O372(H2O)72(CH3COO)30}·ca.7NH4CH3COO·ca. 173H2O(3, TBA=tetrabutylammonium) and (DODA)40(NH4)2[(H2O)nMo132O372(CH3COO)3o(H20)72](4, DODA=dimethyldioctadecylammonium), reveal that the third-order nonlinearity[x(3)] values of compounds 1, 2 and 3 in the DMF/H2O solution and compound 4 in chloro- form are almost the same, which indicates that the counter cations with different length of alkyl chains show ignora- ble impacts on the NLO susceptibility. In other words, the remarkable third-order nonlinearities[x(3)≈10 19 m2/V2] mainly come from the [MoI32O372(CH3COO)30(H2O)72]42 anions. This fact reveals that the applications of the NLO active polyoxometalates in various environments(such as hydrophilic, hydrophobic, polar, apolar, etc.) can be achieved by simply varying cations to meet the demands in the design of diverse devices. Keywords Keplerate type polyoxometalate; Nonlinear optical property; Z-Scan technique; Self-defocusing; Reverse saturable absorption
ZHOU Yunshan QU Ningning WANG Xuan ZHANG Lijuan SHI Zonghai HASSAN ul Sadaf
关键词:SELF-DEFOCUSING
Keplerate巨型纳米多孔聚氧钼酸盐作为可重复使用催化剂用于合成1,2,4,5-四取代咪唑(英文)
2014年
The Keplerate‐type giant nanoporous isopolyoxomolybdate (NH4)42[MoVI72MoV60O372‐(CH3COO)30(H2O)72], denoted {Mo132}, has been used as a catalyst for the synthesis of1,2,4,5‐tetrasubstituted imidazoles by the one‐pot, four‐component thermal reaction of benzil with aromatic aldehydes, primary amines, and ammonium acetate under solvent‐free conditions. The catalyst was prepared according to a previously published literature procedure using inexpensive and readily available starting materials, and subsequently characterized by FT‐IR, UV and X‐ray diffraction spectroscopy, as well as microanalysis. The results showed that {Mo132} exhibited high catalytic activity towards the synthesis of 1,2,4,5‐tetrasubstituted imidazoles, with the desired products being formed in good to high yields. Furthermore, the catalyst was recyclable and could be reused at least three times without any discernible loss in its catalytic activity. Overall, this new catalytic method for the synthesis of 1,2,4,5‐tetrasubstituted imidazoles provides rapid access to the desired compounds following a simple work‐up procedure, and avoids the use of harmful organic solvents. This method therefore represents a significant improvement over the methods currently available for the synthesis of tetrasubstituted imidazoles.
Ahmad NakhaeiAbolghasem Davoodnia
关键词:取代咪唑纳米多孔E型催化活性
含Keplerate型多金属氧酸盐对罗丹明B的异相光催化降解
本发明公开了含Keplerate型多金属氧酸盐对罗丹明B的异相光催化降解,解决水溶性含氮染料均相催化降解中催化剂难回收分离和循环,属于催化领域,采用一种Keplerate型多金属氧酸盐的四丁基铵盐(NH<Sub>4</S...
周云山熊添张立娟
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含Keplerate型多金属氧酸盐对罗丹明B的异相光催化降解
本发明公开了含Keplerate型多金属氧酸盐对罗丹明B的异相光催化降解,解决水溶性含氮染料均相催化降解中催化剂难回收分离和循环,属于催化领域,采用一种Keplerate型多金属氧酸盐的四丁基铵盐(NH<Sub>4</S...
周云山熊添张立娟

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张立娟
作品数:90被引量:15H指数:3
供职机构:北京化工大学
研究主题:多金属氧酸盐 稀土 配合物 KEPLERATE 磷钨酸
周云山
作品数:94被引量:21H指数:4
供职机构:北京化工大学
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熊添
作品数:3被引量:0H指数:0
供职机构:北京化工大学
研究主题:多金属氧酸盐 KEPLERATE 回收 均相催化 罗丹明B
尹建波
作品数:13被引量:17H指数:3
供职机构:燕京理工学院
研究主题:MO H2O CEES KEPLERATE 落叶
陈维林
作品数:63被引量:32H指数:4
供职机构:东北师范大学
研究主题:多金属氧酸盐 染料敏化太阳能电池 修饰 光阳极 太阳能电池