Facile Hydrothermal Synthesis and Basic Gas-Sensing Properties of Two Three-Dimensional Nanostructures of SnO₂

Figure 3

SEM images of the sheet-spheres and pointed columnar-spheres: (a) 1 μm, (b) 500 nm, (c) 1 μm, and (d) 500 nm.

(a)

(b)

(c)

(d)