Figure 3
From: A room-temperature ultrasonic hydrogen sensor based on a sensitive layer of reduced graphene oxide
Frequency shift of the sensor towards H2. (a,b) Shifts of the central frequency of the sensor to 100 ppm H2 mixed in (a) dry argon and (b) argon with a relative humidity of 60%. (c,d) Shifts of the central frequency of the sensor to 1000 ppm H2 mixed in (c) dry air and (d) air with a relative humidity of 60%. (e) Shifts of the central frequencies of the sensors with RGO-120 °C and RGO-180 °C sensitive layers to 100 ppm H2 mixed in argon with a relative humidity of 60%.
