Enhancing by nano-engineering: Hierarchical architectures as oxygen reduction/ evolution reactions for zinc-air batteries
Enhancing by nano-engineering: Hierarchical architectures as oxygen reduction/ evolution reactions for zinc-air batteries
复制标题
通过纳米工程增强：锌空气电池氧还原/析出反应的分层结构
DOI：
10.1016/j.jpowsour.2019.226919
复制
发表时间：
2019-10-31
影响因子：
9.2
通讯作者：
Wei, Zidong
中科院分区：
文献类型：
--
作者：
Najam, Tayyaba;Shah, Syed Shoaib Ahmad;Wei, Zidong
开发高效的电催化剂是降低电化学设备总体成本的迫切需要。通常是通过界面修饰来提高活性位点的内在活性，通过结构优化来促进物质的运输。在此，我们通过控制金属有机框架涂层层状双氢氧化物纳米片的热解，合理设计了一系列碳基分层结构作为双功能电催化剂。制备了分散在碳化金属氧化物纳米片上的纳米颗粒、垂直生长在碳化金属氧化物纳米片上的碳纳米管和垂直生长在碳化金属氧化物纳米片上的碳纳米片三种具有层次结构的催化剂。其中，垂直生长在碳化金属氧化物纳米片电催化剂上的碳纳米管由于其独特的分层多孔结构，具有最大的电化学表面积、最低的电荷传递电阻和最快的传质速率。这些特性使其在半波电位（835 mV）和低过电位（280 mV）方面具有优异的氧还原/析出反应催化活性，使其成为锌空气电池的重要电催化剂，具有良好的充放电性能，峰值功率密度（235 mW cm(-2)），比电容（875 mAh g(-1)）和比贵金属催化剂更好的稳定性。
Developing efficient electrocatalysts is extremely desirable to decrease the overall cost of electrochemical devices. It usually lies in interface modification for improving intrinsic activity of active sites, and structural optimization for facilitating mass transport. Herein, we rationally design a series of carbon-based hierarchical architectures as bifunctional electrocatalysts through control pyrolysis of metal-organic frameworks coated layered double hydroxide nanoplatelets. Three kinds of catalysts with hierarchical structures are produced, nanoparticles dispersed on carbonized metal oxide nanosheets, carbon nanotubes vertically grown on carbonized metal oxide nanosheets, and carbon nanosheets vertically grown on carbonized metal oxide nanosheets. Among them, the carbon nanotubes vertically grown on carbonized metal oxide nanosheets electrocatalyst possesses the highest electrochemical surface area, lowest charge-transfer resistance, and the fast mass transfer rate, owing to its unique hierarchical porous structure. These properties lead to excellent catalytic activities for oxygen reduction/evolution reactions in terms of half-wave potential (835 mV) and low overpotential (280 mV), which make it a significant electrocatalyst for zinc-air batteries with respectable discharge-charge performance, peak power density (235 mW cm(-2)), specific capacitance (875 mAh g(-1)) and better stability than precious metal catalysts.