Fig. 2: Morphology and composition characterization of GNW-ZNS.
From: Anti-biofouling NH3 gas sensor based on reentrant thorny ZnO/graphene hybrid nanowalls
a–c SEM images of GNW, GNW-ZF, and GNW-ZNS: (a1–2) top views and (a3) side view of GNW showing the vertical nanowall structure; (b1–2) top views and (b3) side view of GNW-ZF; the ZnO layer was deposited on the top of the GNWs; (c1–2) top views and (c3) side view of GNW-ZNS; ZnO spikes were grown on the top portion of the GNW. The reentrant features can be observed in c3. d EDS spectroscopy of GNW-ZNS (substrate: Si/SiO2) confirmed the chemical composition of Zn, O, and C, showing that ZnO could only form on the top part. e Raman spectra confirmed the few-layer graphene structures in both GNW and GNW-ZNS
