Research Progress on Humidity-Sensing Properties of Cu-Based Humidity Sensors: A Review

Figure 11

SEM micrographs of CuO nanosheets prepared with different concentrations of NaOH: (a) 0.5 mol/l (sample 1), (b) 0.125 mol/l (sample 2), and (c) 0.05 mol/l (sample 3) [70].

(a)

(b)

(c)