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.