钴及其氧化物纳米颗粒镶嵌氮掺杂碳纳米阵列的电催化水解性能研究

Cobalt/Cobalt oxides nanoparticles embedded Nitrogen-doped carbon nanostructures for efficient overall water splitting

金属有机物框架(MOFs),特别是其衍生物,因其高比表面积的多孔结构,在能量存储与转换领域表现出极大的应用前景.本文以三维(3D)柔性高导碳布(Carbon Cloth/CC)为衬底,Co-MOF(ZIF-67)为前驱体得到钴/钴氧化物纳米颗粒(Co-O NPs)镶嵌的氮掺杂碳纳米阵列结构(Co-O/NC).常温溶液生长在CC上得到均匀的ZIF-67纳米棒阵列(NRAs),经由Ar/H2还原成Co NPs镶嵌的中空的NC阵列结构(Co/NC),再由空气退火处理活化得到Co-O/NC,并直接用作碱性双功能电化学全水解电极.在1 mol/L的KOH电解液中,Co-O/NC样品的HER性能相对较好,源于其相对较高的动力学性能、较小的电荷转移电阻,以及较多的活性位参与到HER过程中.而对于OER性能,Co/NC则表现稍好,因为Co-O/NC在预氧化过程形成更稳定的Co—O键,不便于OER中间体的有效吸附与解吸附.本项工作为NPs镶嵌的中空纳米阵列结构的设计,以及在其基础之上高维度复合结构的构建,高性能电化学和柔性多功能器件的设计制备提供了良好的实例.

Metal-organic frameworks(MOFs)and its derivates are promising candidates for energy storage and conversion via its porous structure and high specific areas.Herein,Cobalt/Cobalt Oxides nanoparticles(NPs)embedded Nitrogen-doped Carbon nanostructures(Co-O/NC)were obtained on three-dimension(3D)flexible electric Carbon Clothes(CC)substrate from ZIF-67.Uniform ZIF-67 nanorod arrays(NRAs)were first synthesized by a solution route.And then ZIF-67 NRAs were converted into hollow Nitrogen-doped Carbon Nanostructures(NC)with embedded Co NPs(Co/NC)via Ar/H2 annealing.Further,Co/NC were activated through air annealing and converted into Co-O/NC which was used as electrodes for electrocatalysis overall water splitting.In 1.0 mol/L KOH aqueous electrolyte,Co-O/NC exhibited the superior HER activity,which were attributed to the excellent HER dynamic properties,smaller charge transfer resistance and more active sites participated in the HER process.For OER,Co/NC exhibited a little better performance.The lower OER properties of Co-O/NC stemmed from the more stabilized Co-O bond in the pre-oxidation process,which slowed down the activity of OER intermediate.This work might provide a favorable example of rational design of NPs embedded hollow nanostructure arrays,and the composite electrodes based of which,for the future electronic devices with high electrochemical performance and mechanical exibility multifunctions.