Fig. 1

(a) SEM image of (a) unadsorbed fluorine at 10 µm (b) fluoride adsorption at 10 µm(c) unadsorbed fluorine at 4 µm (d) fluoride adsorption at 4 µm(e) EDS energy spectrum of unadsorbed fluoride(f) EDS energy spectrum after fluoride adsorption.

(a) SEM image of (a) unadsorbed fluorine at 10 µm (b) fluoride adsorption at 10 µm(c) unadsorbed fluorine at 4 µm (d) fluoride adsorption at 4 µm(e) EDS energy spectrum of unadsorbed fluoride(f) EDS energy spectrum after fluoride adsorption.