Fig. 1: Experimental realization of molybdenene.

a, Schematic diagram depicting graphene-catalysed microwave synthesis of molybdenene sheet (intense electric field breaks Mo–S bonds and Mo atoms move out through the expanded graphene network), Mo, S and C atoms are represented in pink, yellow and grey respectively, b,c, FESEM images of flat atomic sheets obtained by sonication followed by centrifugation of Mo whiskers. d,e, AFM images showcasing staircase-like features (each step being 0.4 nm) indicative of screw-dislocation-mediated growth of Mo whiskers (d,e) and showing monolayer Mo sheet, that is, molybdenene, transferred onto SiO₂ substrate (f). g, Large-area HAADF image, which is taken to acquire EELS in the marked green region. h, EELS spectrum of synthesized Mo sheets in the high-loss region ranging from 2,400 to 3,300 eV. Int. intensity; a.u., arbitrary units. i, EELS spectrum ranging from 0 to 400 eV showing a zero-loss peak and low-loss plasmon oscillation peaks. j, EELS spectrum acquired in the high-loss region (200–450 eV) depicting a highly intense M₄ peak.