Design of ultrahigh-response gas sensor based on Pd-WO3/WS2 ternary nanocomposites for ultrafast hydrogen detection

In this research, WS2 nanomaterials were synthesized by a hydrothermal method at first. Then, partially oxidized WS2 through calcination to obtain WO3/WS2 binary materials via calcination. Among different calcination temperatures (400 oC, 350 oC and 300 oC), the WO3/WS2 with the best performance calcined at 300 oC was selected to load Pd on the surface. Particularly, the 2 at% Pd-WO3/WS2 exhibited the better hydrogen sensitivity compared to the load of Pd was 5 at%, displaying an ultrahigh response of 4227.35 at 125℃ with a faster response/recovery time of 1/25 s to 1000 ppm H2. The property of the ternary nanocomposites was superior to previously reported binary WO3 materials due to the synergistic effect of its unique microstructure, the formation of p-n-p heterojunction, and the electronic sensitization of palladium. This work designed a novel ternary material applied to rapid hydrogen detection for the first time.