Fig. 7: The strategies for improving the sensing linearity of Pd based H2 sensors.
a Schematic illustration of perfectly aligned Pd NWs based H2 sensor with inhibited phase transition. b Schematic of the internal lattice structure of Pd NWs with two phases; c Gibbs free energy change of PdHx phase transition (ΔGα→β, kJ/mol) according to stress (σ) at four different concentrations of H2. d Ratio of a cross-sectional area with a stress greater than 0.25 GPa to the total area with respect to wNW and tNW; Influence of e tNW and f wNW of the Pd NWs to the H2 sensing performance; G Gas response based on optimized Pd NWs sensor (wNW = 160 nm, tNW = 15 nm) as increasing and decreasing H2 concentration118. Copyright 2022, American Chemical Society. h Schematic graph and I, j SEM images of the nanoelectromechanical H2 sensor; k Hysteresis characteristics depend on the sensor temperature; l Response time and m linear gas response according to the H2 concentrations at 65 °C119. Copyright 2023, American Chemical Society
