Bimetal Pd/Ni functionalized WO3 nanospheres for sensitive low-concentration hydrogen detection

In this study, we used a hydrothermal method to prepare WO3 nanospheres doped with a bimetal of Pd and Ni and used them in hydrogen sensing. The results show that the bimetal-doped WO3 nanospheres have a higher response, faster response/recovery time, and better selectivity than single metal-doped WO3. Moreover, they still have a high response to hydrogen at a low concentration. With 5 ppb of hydrogen, the sensor's response can reach 1.5, which is 1.5 times greater than that of pure WO3. Furthermore, the bimetal-doped WO3 has a shorter response time (14 s) and recovery time (8 s). This superior performance of the Pd/Ni-doped WO3 to hydrogen is most probably because of the strong adsorption of hydrogen, which results from the synergistic effect of two metals.