Co_3O_4 nanosheet-built hollow dodecahedrons via a two-step self-templated method and their multifunctional applications  

两步自模板法制备Co_3O_4纳米片基中空十二面体及其多功能应用（英文）

作　　者：Yuanyuan Li Bo Liu Hong Wang Xingsong Su Lei Gao Fei Zhou Guotao Duan 李圆圆;刘波;王弘;苏星松;高磊;周飞;段国韬

机构地区：[1]Key Lab of Materials Physics,Anhui Key Lab of Nanomaterials and Nanotechnology,Institute of Solid State Physics,Chinese Academy of Sciences,Hefei 230031,China [2]University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China Materials》2018年第12期1575-1586,共12页中国科学（材料科学（英文版）

基　　金：financial support from the National Key R&D Program of China(2016YFC0201103);the Natural Science Foundation of China(51471161 and 11674320);Youth Innovation Promotion Association CAS and Key Research Projects of the Frontier Science CAS(QYZDB-SSW-JSC017)

摘　　要：TheCo3O4 nanosheet-built hollow dodecahedrons(Co3 O4 NSHDs) were fabricated via a controllable twostep self-templated method. The ZIF-67 dodecahedrons were prepared as first self-template to synthesize the Co-LDH hollow dodecahedrons, which were further used as self-template to fabricateCo3O4 NSHDs by a controlled calcination.The proposed two-step self-templated method not only brings hollow structures without auxiliary template, ultrathin nanosheet, ultrafine grains, and large surface areas, but also allows the easy and uniform surface modification, as demonstrated of PdO modification. TheCo3O4 NSHDs with above features could show multifunctional applications, such as sensing and catalysis. Experiments suggest that theCo3O4 NSHDs show good gas sensing performances to trimethylamine at a low operating temperature(100 oC). They can be further enhanced by PdO surface modification, which have a low detection limit(250 ppb) and a short response time(4.5 s).In addition, theCo3O4 NSHDs exhibited excellent oxygen evolution reaction performances with a low overpotential of359 mV, low Tafel slope of 80.7 mV dec-1 and low electrochemical impedance, which was superior to those for theCo3O4 NCs obtained by directly calcinating the ZIF-67 templates,Ni foam and most common metal oxides catalysts.Co_3O_4纳米片基中空十二面体可以通过一种可控的自模板法制备而成.首先利用ZIF-67为自模板合成Co-LDH中空十二面体,然后将其作为自模板通过优化退火的方式制备Co_3O_4纳米片组成的中空十二面体(Co_3O_4NSHDs).利用该两步自模板法制得的Co_3O_4NSHDs不仅具有中空结构、超薄的纳米片、超细的纳米颗粒,还易实现表面的均匀修饰(如PdO的均匀修饰).拥有上述特点的Co_3O_4NSHDs可以实现多方面的应用,例如气敏和催化.实验结果表明Co_3O_4NSHDs对三甲胺气体在低工作温度(100°C)下表现出很好的敏感特性.在PdO表面修饰后,对三甲胺的气敏性能进一步增强,如更低的检测下限(250 ppb)和快速的气敏响应(4.5 s).另外,该材料也表现出优异的析氧反应活性.和直接利用ZIF-67退火制得的Co_3O_4纳米笼、泡沫镍和大多数金属氧化物催化剂相比,它具有较低的过电势(359 mV)、小的阻抗和小的塔菲尔斜率(80.7 mV dec^(-1)).

关 键 词：Co3O4 self-templated method gas sensing oxygen evolution reaction 

分 类 号：O614.812[理学—无机化学] TB383.1[理学—化学]