Fig. 2. Morphology and composition characterization of ultrathin 2D As/As_xO_y@PDA@M NSs.

a TEM images of As/As_xO_y NSs, scale bar = 100 nm. b HRTEM images of As NSs, scale bar = 1 nm. c HRTEM images of As/As_xO_y NSs (red circle: lattice fringes of As; blue circle: amorphism of As_xO_y), scale bar = 1 nm. d TEM images of As/As_xO_y@PDA NSs, scale bar = 100 nm. e TEM images of As/As_xO_y@PDA@M NSs, scale bar = 100 nm. f–h AFM images of As/As_xO_y NSs, As/As_xO_y@PDA NSs, and As/As_xO_y@PDA@M NSs, respectively, scale bar = 100 nm. i SEM-EDS mapping of As/As_xO_y@PDA@M NSs: green (As), purple (C), orange (N), pink (O), and red (P), scale bar = 50 nm. For these morphology characterizations of fabricated As-based NSs, three times each experiment was repeated independently with similar results.