Amperometric Formaldehyde Sensor Based on a Pd Nanocrystal Modified C/Co₂P Electrode

Figure 9

(a) Amperometric current responses of the C/Pd (black line), C/Co₂P composite (blue line), and C/Co₂P/Pd (red line) composites based gas sensors to 3 ppm formaldehyde. (b) Typical dynamic current response curves of C/Co₂P/Pd sensor to formaldehyde ranging from 1 ppm to 10 ppm (inset: calibration curve). (c) Enlarged part of the current responses to 3 ppm HCHO gas of the C/Pd (red line), C/Co₂P composite (green line), and C/Co₂P/Pd (black line) electrode based gas sensors. (d) Bar plot of current response of the C/Co₂P/Pd composites based formaldehyde sensor to different interfering gases under exposure to 10 ppm formaldehyde, 10 ppm NO, 10 ppm NO₂, 10 ppm SO₂, 5000 ppm CO₂, and 50 ppm CO. Applied potential to working electrode was +0.75 V (versus Ag/AgCl).

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