Self-transforming ultrathin α-Co(OH)2 nanosheet arrays from metal-organic framework modified graphene oxide with sandwichlike structure for efficient electrocatalytic oxygen evolution  

作　　者：Mengqiu Huang Weiwei Liu Lei Wang Jiwei Liu Guanyu Chen Wenbin You Jie Zhang Lijun Yuan Xuefeng Zhang Renchao Che 

机构地区：[1]Laboratory of Advanced Materials,Department of Materials Science and Collaborative Innovation Center of Chemistry for Energy Materials(iChetn),Fudan University,Shanghai 200438,China [2]College of Materials and Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310012,China [3]Laboratory of Advanced Materials,Department of Materials Science and Collaborative Innovation Center of Chemistry for Energy Materials(iChem),Fudan University,Shanghai 200438,China

出　　处：《Nano Research》2020年第3期810-817,共8页纳米研究（英文版）

基　　金：This work was supported by the National Basic Research Program of China(No.2018YFA209102);the National Natural Science Foundation of China(Nos.11727807,51725101,51672050,and 61790581).

摘　　要：Developing efficient and low-cost electrocatalysts for oxygen evolution reaction(OER)with high electrochemical activity and durability for diverse renewable and sustainable energy technologies remains challenging.Herein,an ultrasonic-assisted and coordination modulation strategy is developed to construct sandwich-like metal-organic framework(MOF)derived hydroxide nanosheet(NS)arrays/graphene oxide(GO)composite via one-step self-transformation route.Inducing from unsteady state,the dodecahedral ZIF-67 with Co^2+in tetrahedral coordination auto-converts into defect-rich ultrathin layered hydroxides with the interlayered ion NO3-.The self-transforming a-Co(OH)2/GO nanosheet arrays from ZIF-67(Co(OH)2-GNS)change the coordination mode of Co^2+and bring about the exposure of more metal active sites,thereby enhancing the spatial utilization ratio within the framework.As monometal-based electrocatalyst,the optimized Co(OH)2-GNS exhibits remarkable OER catalytic performance evidenced by a low overpotential of 259 mV to achieve a current density of 10 mA·cm-2 in alkaline medium,even exceeding commercial RuO2.During the oxygen evolution process,electron migration can be accelerated by the interfacial/in-plane charge polarization and local electric field,corroborated by the off-axis electron holography.Density functional theory(DFT)calculations further studied the collaboration between ultrathin Co(OH)2 NS and GO,which leads to lower energy barriers of intermediate products and greatly promotes electrocatalytic property.

关 键 词：metal-organic framework oxygen evolution reaction ultrathin nanosheet arrays cobaltous hydroxide charge transfer 

分 类 号：O64[理学—物理化学]