Browsing by Author "Li, Zhe"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Moire superlattices at the topological insulator Bi2Te3
    Schouteden, Koen; Li, Zhe; Chen, Taishi; Song, Fengqi; Partoens, Bart; Van Haesendonck, Chris; Park, Kyungwha (Springer Nature, 2016-02-08)
    We report on the observation of complex superlattices at the surface of the topological insulator Bi2Te3. Scanning tunneling microscopy reveals the existence of two different periodic structures in addition to the Bi2Te3 atomic lattice, which is found to strongly affect the local electronic structure. These three different periodicities are interpreted to result from a single small in-plane rotation of the topmost quintuple layer only. Density functional theory calculations support the observed increase in the DOS near the Fermi level, and exclude the possibility that strain is at the origin of the observed Moire pattern. Exploration of Moire superlattices formed by the quintuple layers of topological insulators holds great potential for further tuning of the properties of topological insulators.
  • Thumbnail Image
    Two-dimensional transition metal carbides as supports for tuning the chemistry of catalytic nanoparticles
    Li, Zhe; Yu, Liang; Milligan, Cory; Ma, Tao; Zhou, Lin; Cui, Yanran; Qi, Zhiyuan; Libretto, Nicole; Xu, Biao; Luo, Junwei; Shi, Enzheng; Wu, Zhenwei; Xin, Hongliang; Delgass, W. Nicholas; Miller, Jeffrey T.; Wu, Yue (2018-12-10)
    Supported nanoparticles are broadly employed in industrial catalytic processes, where the active sites can be tuned by metal-support interactions (MSIs). Although it is well accepted that supports can modify the chemistry of metal nanoparticles, systematic utilization of MSIs for achieving desired catalytic performance is still challenging. The developments of supports with appropriate chemical properties and identification of the resulting active sites are the main barriers. Here, we develop two-dimensional transition metal carbides (MXenes) supported platinum as efficient catalysts for light alkane dehydrogenations. Ordered Pt3Ti and surface Pt3Nb intermetallic compound nanoparticles are formed via reactive metal-support interactions on Pt/Ti3C2Tx and Pt/Nb2CTx catalysts, respectively. MXene supports modulate the nature of the active sites, making them highly selective toward C-H activation. Such exploitation of the MSIs makes MXenes promising platforms with versatile chemical reactivity and tunability for facile design of supported intermetallic nanoparticles over a wide range of compositions and structures.