Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant...Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant metal,oxygen,and heteroatoms are nanoclusters with defined structures.Benefitting from the inherent advantages of POMs,highly dispersive and"unprotected"Ir nanoparticles originating from Ir-based colloid solution were successfully anchored on POM-derived WO_(3)/rGO nanocomposites for the first time.Interestingly,the obtained hybrid material Ir/WO_(x)/rGO delivered improved electrocatalytic performance for water splitting,which is attributed to the addition of only quite small amount of POM derivatives.This work is also the first proof that POM can be employed as precursor to construct metal oxides to support Ir catalysts,providing a new vision for the design of advanced multi-metal electrocatalysts.展开更多
An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer...An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer vesicles formed from a hexavanadate cluster functionalized with two alkyl chains are highly efficient catalysts for the oxidation of 3,3＇,5,5＇-tetramethylbenzidine （TMB） with H2O2 at room temperature, a widely used model reaction mimicking the activity of peroxidase in biological catalytic oxidation processes. Driven by hydrophobic interactions, the double-tailed hexavanadate-headed amphiphiles can self-assemble into bilayer vesicles and create hydrophobic domains that segregate the TMB chromogenic substrate. The reaction of TMB with H2O2 takes place at the interface of the hydrophilic and hydrophobic domains, where the reagents also make contact with the catalytic hexavanadate clusters, and it is approximately two times more efficient compared with the reactions carried out with the corresponding unassembled systems. Moreover, the assembled vesicular system possesses affinity for TMB comparable to that of reported noble metal mimic nanomaterials, as well as a higher maximum reaction rate.展开更多
基金supported by Beijing Municipal Science and Technology Project(No.Z161100001116080)Cross training plan for high level talents in Beijing colleges and university+5 种基金Major Project of the Ministry of Science and Technology(No.2016YFA0200904,2016YFC0600605)Chinese Academy of Geological Sciences Fundamental Research projects(No.YYWF201619)Comprehensive geological survey of Yunnan Anning Mine Concentration Zone(No.DD20190589)National Natural Science Foundation of China(No.21271068,21401050)the Natural Science Foundation of Hubei Province(No.2015CFA131)Wuhan Applied Basic Research Program(No.2014010101010020)Z.X.,P.W.,P.J.,and M.L.provided the research funding
文摘Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant metal,oxygen,and heteroatoms are nanoclusters with defined structures.Benefitting from the inherent advantages of POMs,highly dispersive and"unprotected"Ir nanoparticles originating from Ir-based colloid solution were successfully anchored on POM-derived WO_(3)/rGO nanocomposites for the first time.Interestingly,the obtained hybrid material Ir/WO_(x)/rGO delivered improved electrocatalytic performance for water splitting,which is attributed to the addition of only quite small amount of POM derivatives.This work is also the first proof that POM can be employed as precursor to construct metal oxides to support Ir catalysts,providing a new vision for the design of advanced multi-metal electrocatalysts.
基金We gratefully acknowledge the financially support by the National Natural Science Foundation of China （Nos. 21631007, 21401050, 21471087 and 21271068）, Beijing Natural Science Foundation （No. 2164063）, China Postdoctoral Science Foundation （No. 2014M560948）, the State Key Laboratory of Natural and Biomimetic Drugs （No. K20160202）, the National Natural Science Foundation of Hubei Province （No. 2015CFA131） and Wuhan Applied Basic Research Program （No. 2014010101010020）. T. B. L. acknowledges support from the National Science Foundation （No. CHE1607138） and the University of Akron.
文摘An emerging method for effectively improving the catalytic activity of metal oxide hybrids involves the creation of metal oxide interfaces for facilitating the activation of reagents. Here, we demonstrate that bilayer vesicles formed from a hexavanadate cluster functionalized with two alkyl chains are highly efficient catalysts for the oxidation of 3,3＇,5,5＇-tetramethylbenzidine （TMB） with H2O2 at room temperature, a widely used model reaction mimicking the activity of peroxidase in biological catalytic oxidation processes. Driven by hydrophobic interactions, the double-tailed hexavanadate-headed amphiphiles can self-assemble into bilayer vesicles and create hydrophobic domains that segregate the TMB chromogenic substrate. The reaction of TMB with H2O2 takes place at the interface of the hydrophilic and hydrophobic domains, where the reagents also make contact with the catalytic hexavanadate clusters, and it is approximately two times more efficient compared with the reactions carried out with the corresponding unassembled systems. Moreover, the assembled vesicular system possesses affinity for TMB comparable to that of reported noble metal mimic nanomaterials, as well as a higher maximum reaction rate.
