fig10

Figure 10. (A) Pd/Si-mWO₃ microspheres-based H₂ gas sensing. SEM images of Si-mWO₃ (A₁); Sensing response to 50 ppm different gases (A₂); Response curves toward various H₂ concentrations at 210 °C (A₃). Figure 10A is quoted with permission from Zhang et al.^[5]; (B) TiO_x-In₂O₃-based NO₂ gas sensing. Schematic illustration of gas sensing mechanism under light activation (B₁); cyclic performance of 5TiO_x-In₂O₃ against 1 ppm NO₂ (B₂); average response values toward 3 ppm NO₂ at dry, 20%, 50%, and 80% RH conditions (B₃). Figure 10B is quoted with permission from Park et al.^[201]; (C) WO₃/Au-based 3-hydroxy-2-butanone gas sensing. Dynamic response-recovery characteristic curves of WO₃/Au-based sensors exposed to different concentrations of 3-hydroxy-2-butanone gas (C₁); Scheme illustration of MOS-based gas sensors applied in the selective detection of 3-hydroxy-2-butanone (C₂). Figure 10C is quoted with permission from Ma et al.^[209]; (D) Au@m-WO₃ spheres-based isoprene gas sensing. Schematic of a man running on a treadmill (D₁). Concentrations of isoprene and gas response of the Au@m-WO₃ sensor to the exhaled breath as a function of running time (D₂). Figure 10D is quoted with permission from Park et al.^[229]. SEM: scanning electron microscope; ppm: parts-per-million.