高导电性和催化活性的Janus-TiNbCO_(2)析氢反应催化材料  

Janus-TiNbCO_(2) for Hydrogen Evolution Reaction with High Conductivity and Catalytic Activity

作　　者：徐黎黎[1] 任冬燕[1] 赵骁锋 易勇[2] Li-Li Xu;Dong-Yan Ren;Xiao-Feng Zhao;Yong Yi(Mianyang Vocational and Technical College,Department of Materials Enginerring,Mianyang 621000,Sichuan,China;School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Department of Physics and Astronomy,Uppsala University,75120 Uppsala,Sweden)

机构地区：[1]绵阳职业技术学院,材料工程系,四川绵阳621000 [2]西南科技大学,材料科学与工程学院,四川绵阳621010 [3]乌普萨拉大学,物理与天文学系,瑞典乌普萨拉SE-75120

出　　处：《电化学》2021年第5期570-578,共9页Journal of Electrochemistry

基　　金：国家自然科学基金项目(No.12105236)资助。

摘　　要：探寻具有高导电性和高催化活性的析氢反应(HER)催化材料一直是可持续能源发展研究中的热点。Ti_(2)C具有表面活性位点多和优良的力学稳定性、导电性等,已成为潜在的制氢催化剂。然而,终端O修饰Ti_(2)C表面,会降低该材料的导电性,进而限制了电子在价带与导带间的输运。本研究通过Nb掺杂,构建双电层Janus-TiNbCO_(2),并借助VASP软件研究了Janus-TiNbCO_(2)的能带结构、HER性能和HER反应路径过渡态。结果表明,Janus-TiNb-CO_(2)为导体材料,其在应力、氧空位缺陷和H^(*)覆盖度的影响下,均表现出极优异的催化活性,计算获得的最优△G_(H^(*))值为0.02 eV。H^(*)在Janus-TiNbCO_(2)上可能以Heyrovsky路径进行反应,该路径的迁移能势垒为0.23 eV。Janus-TiNbCO_(2)是一种具有HER应用前景的催化材料。Exploring the potential hydrogen evolution reaction(HER)catalysts with the high activity and high conductivity has always been a hot spot in the research of renewable energy development.Ti_(2)C,as one of the 2D-MXene,has excellent properties relating to many active sites,mechanical stability,conductivity,etc.,and has become a potential HER catalyst.However,the modification of the surface of Ti_(2)C by terminal O will reduce the conductivity,thereby limiting the transport of electrons between the valence band and the conduction band.In this study,an electric double layer Janus-TiNbCO_(2)was constructed by Nb doping.The band property,HER activity and HER reaction path of Janus-TiNbCO_(2)are studied by the first-principles calculations.The results show that Nb doping increases the distance between Ti and O atoms,which increases the lattice parameters of Janus-TiNbCO_(2)comparing with that of Ti_(2)CO_(2)structure.The Janus-TiNbCO_(2)structure is stable by calculating the thermodynamic stability at 500 K using AIMD method.The band gap of Ti_(2)CO_(2)is approximate 0.9 eV.After Nb doping,the orbital hybridization between Nd-3d and O-2p affects the electronic rearrangement of Ti-3d,leading that Janus-TiNbCO_(2)has the metal band structure.In Janus-TiNbCO_(2),both Ti and Nb surfaces adsorb H^(*)by O site,where the△G_(H^(*))(@Ti)=-0.55 eV,△G_(H^(*))(@Nb)=0.02 eV,showing Ti and Nb surfaces have different catalytic activities.Comparing with graphenes,e.g.,h-B_(2)O,Pt,and g-C_(3)N_(4),Janus-TiNbCO_(2)has better catalytic activity.The charge distribution of Janus-TiNbCO_(2)near the Fermi level was analyzed by HSE-06 function.The result reveals that O atoms on the Ti surface exhibit charge unsaturation at the Fermi level,while those on Nb surface strong saturation.Moreover,the effects of H^(*)coverage and strains(+2%~+4%)on the catalyst activity of Janus-TiNbCO_(2)are studied.When the H^(*)coverage is low,the optimal△G_(H^(*))of Nb surface is approximate 0.02 eV,while Ti surface has an excellent catalytic activity at hi

关 键 词：MXene Janus-TiNbCO_(2) 能带 析氢反应 

分 类 号：TQ116.2[化学工程—无机化工] TQ426