Example：10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
Imaging and Dynamics of Water Hexamer Confined in Nanopores. ACS Nano (IF18.027), Pub Date : 2019-09-09, DOI: 10.1021/acsnano.9b04835 Nan Si,Tao Shen,Dechun Zhou,Qin Tang,Yixuan Jiang,Qingmin Ji,Han Huang,Wei Liu,Shuang Li,Tianchao Niu
Epitaxial two-dimensional (2D) nanostructures with regular patterns show great promise as templates for adsorbate confinement. Prospectively, employing 2D semiconductors with reduced density of states leads to a long excited-state lifetime that allows us to directly image the dynamics of the adsorbate. We show that epitaxial blue phosphorene (blueP) on Au(111) provides such a platform to trap water molecules in the periodic nanopores without formation of strong bonds. The trapped water aggregate is tentatively assigned to a hexamer based on our scanning tunneling microscopy studies and first-principles calculations. Real-space observation of conformational switching of the hexamer induced by inelastic electrons is achieved by using low-temperature scanning tunneling microscopy with molecular resolution. We found a localized interfacial charge rearrangement between the water hexamer and P atoms underneath that is responsible for the reversible desorption and adsorption of water molecules by changing the sample bias polarity from positive to negative, offering a promising strategy for engineering the electronic properties of blueP.