Ultrafast response and recovery in advanced H2 sensing: Self-assembled fruit-leaf-like PdO/WO3 nanostructures

As hydrogen is widely used as a clean energy source, the hazards of its flammable and explosive properties are gradually emphasized. Therefore, it is imminent to develop a hydrogen sensor with high response, fast detection speed and low detection limit. In this paper, a PdO/WO 3 composite with fruit-leaf-like structure was synthesized by in-situ hydrothermal and self-assembly impregnation method, and its H 2 sensing performance was investigated. The results show that the self-assembled loading of PdO can greatly improve the H 2 sensing performance of WO 3 , in which the PdO/WO 3 -1 sensor exhibits a very high response value (338.7) and a very short response/recovery time (1 s/4 s) at 120°C to 100 ppm H 2 . The enhanced sensor performance is mainly due to the catalytic effect of the noble metal PdO on H 2 and the synergistic effect between WO 3 and PdO. The growth rhythm of PdO nanoparticles and the effect on the H 2 sensing performance of PdO/WO 3 composites were also explained by varying the concentration of PdCl 2 solution. The density functional theory calculation proves that the hydrogen sensing performance is improved after the combination of PdO and WO 3 . This study provides a feasible solution for the development of high-performance WO 3 -based H 2 sensors.