Combination of Pd loading and electron beam irradiation for superior hydrogen sensing of electrospun ZnO nanofibers

We evaluated the hydrogen gas-sensing characteristics of Pd-loaded (0.1, 0.3, 0.6, and 1 wt%) ZnO nanofibers prepared by a facile electrospinning technique and the effect of different electron beam (e-beam) doses (50, 100, and 150 kGy) on sensing performance. The sensor loaded with 0.6 wt% Pd had the highest response to hydrogen among the Pd-loaded sensors. The sensor irradiated with 150 kGy had the high response (R-a/R-g) of 74.7-100 ppb of H-2 at 350 degrees C. Metallization effects in ZnO, the formation of structural defects due to e-beam irradiation, the catalytic activity of Pd, and the presence of ZnO-Pd heterojunctions were the main factors yielding high sensitivity towards H-2. The strategy of combining e-beam irradiation and Pd loading to enhance H-2 sensing can be applied to realize reliable gas sensors and the widespread use of hydrogen as a green energy alternative to fossil fuels.