Pd-Doped SnO₂-Based Sensor Detecting Characteristic Fault Hydrocarbon Gases in Transformer Oil

Figure 3

FESEM images of (a) pure, (b) 1 wt%, (c) 3 wt%, and (d) 5 wt% Pd-doped SnO₂ nanoparticles.

(a)

(b)

(c)

(d)