Pd-Modified LaFeO 3 as a High-Efficiency Gas-Sensing Material for H 2 S Gas Detection.

As a typical p -type semiconductor gas-sensing material, LaFeO 3 has good response stability to H 2 S, but its responsiveness is low, and the detection limit is not low enough for large-scale use in the field of gas sensors. To obtain better performance, we synthesized Pd modified LaFeO 3 using the sol-gel method. A total of 3 wt% of Pd-LaFeO 3 with a high specific surface area had the highest response to H 2 S (36.29-1 ppm) at 120 °C, with relatively fast response-recovery times (19.62/15.22 s), and it had higher selectivity to H 2 S with other gases. Finally, we detected the H 2 S concentrations in the air around the shrimps, and the H 2 S concentrations that we obtained by the 3 wt% Pd-LaFeO 3 in this study were within 10% of those obtained by GC-MS. According to the experimental results, noble-metal surface modification improves the performance of gas-sensing materials, and Pd-LaFeO 3 has considerable potential in H 2 S detection.