LAUSR

Germanene is a 2D allotrope of germanium atoms arranged in a honeycomb structure with Dirac fermion characteristics analogous to graphene and silicene. Formation of germanene is a recent advance, based on evaporation of Ge in an ultrahigh vacuum environment. An alternative method, developed by authors, is its electrochemical growth from aqueous solutions. Initial studies were performed on Au(111) substrates in aqueous solutions of H2GeO3 using in situ scanning tunneling microscopy, voltammetry, surface X-ray diffraction, and coulometry. These results indicated that electrochemically formed germanene domains were formed and covered the surface, although the coherence lengths were short because of the presence of domain walls composed of five- and seven-membered defect rings. The present study has made use of an operando spectroelectrochemical flow cell with a Raman microscope to follow the growth of germanene. Deposits were formed on a surface-enhanced Raman spectroscopy-active Au substrate. Initial spectr...