An oxidation-nitridation-denitridation approach to transform metal solids into foams with adjustable pore sizes for energy applications  

金属固体至多孔泡沫的可控转变及能源领域应用探索

作　　者：Hao Qin Chao Zhen Chunxu Jia Zhiqing Yang Hengqiang Ye Hui-Ming Cheng Gang Liu 秦浩;甄超;贾春旭;杨志卿;叶恒强;成会明;刘岗(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China;Low-Dimensional Material and Device Laboratory,Tsinghua-Berkeley Shenzhen Institute,Tsinghua University,Shenzhen 518055,China)

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China [3]Low-Dimensional Material and Device Laboratory,Tsinghua-Berkeley Shenzhen Institute,Tsinghua University,Shenzhen 518055,China

出　　处：《Science Bulletin》2021年第15期1525-1532,M0003,共9页科学通报（英文版）

基　　金：the National Natural Science Foundation of China(51825204);the Key Research Program of Frontier Sciences CAS(QYZDB-SSW-JSC039)。

摘　　要：Metal foams with hierarchically porous structures are highly desirable in energy applications as active materials or their host substrates.However,conventional preparation methods usually have a quite limited flexibility of adjusting pore size of metal foams.Herein,an alternative new method based on gaseous thermal oxidation-nitridation-denitridation processes was developed to prepare metal(copper and nickel)foams with adjustable pore size by controlling the thermal nitridation temperature.Moreover,this environment-friendly method is independent of the shape of starting pure metal substrates and can be repeatedly applied to the metal substrates to create hierarchical porous structures containing different size pores.As a demonstration of the advantages of the resultant foams with abundant pores by this method,compared with its starting material(commercial Ni foam with the pore size of several millimeters),the resultant hierarchical porous Ni foam gives the remarkably enhanced performance of electrochemical water splitting as HER/OER electrodes and electrochemical energy storage as the host substrate of capacitive material MnO2.The metal foams with adjustable pore size prepared by the developed method will find a wide range of important applications in energy storage and conversion areas.发展以可持续电力资源为驱动力的能源催化与存储技术,是构建可再生能源结构的重要环节.多孔金属是电化学催化和储能领域中理想电极结构,但其可控制备技术亟待突破.本文开发了简单气氛热处理的方法,实现金属固体至多孔泡沫的可控转变.先通过空气热氧化将金属转化为金属氧化物,然后进行氨气热还原处理,转化为金属氮化物后再分解转变回金属,并释放氮气作为发泡剂,最终实现金属从固体到多孔泡沫的转变.以金属铜箔、金属铜管以及泡沫铜为例,实现孔径可调(从几纳米到几十微米)多孔铜的制备.该方法也适用于其他金属如镍等,并通过控制气氛热处理的参数和次数,可实现三维层次孔金属的构建.获得的三维层次孔金属镍在电催化分解水和担载MnO_(2)作为超级电容器电极均展现出十分优异的性能.分解水(10 m A/cm^(2))的电压为1.65 V,搭载MnO_2电极的面电容值可达2.04 F/cm^(2).

关 键 词：Metal foams Hierarchically porous structures Electrocatalytic water splitting SUPERCAPACITOR 

分 类 号：TG146.11[一般工业技术—材料科学与工程]