Ultrasensitive hydrogen sensor based on porous-structured Pd-decorated In2O3 nanoparticle-embedded SnO2 nanofibers

Porous-structured Pd-decorated In2O3 nanoparticle-embedded SnO2 nanofibers are synthesized by electrospinning and a thermal calcination process using hydrothermally synthesized In2O3 nanoparticles. From this process, porous nanofibers can be obtained without any ZnIn2O4 components, and the sensing performance of the nanofibers can be maximized owing to the numerous pores and grain boundaries in their body. Additionally, as Pd nanoparticles form Schottky barriers with a nanofiber body and generate a catalytic effect, the hydrogen-sensing performance of these nanofibers can be increased. However, to significantly enhance the sensing performance of low-concentration hydrogen gas, sensors with more effective structures should be proposed. Hence, the Pd-decorated In2O3 nanoparticle-embedded SnO2 porous nanofibers are synthesized in this study for improved sensing performance. The response of this heterostructured nanofiber is 1291 for 100 ppm hydrogen gas, and the nanofiber exhibits a remarkable sensing performance, which is enhanced by 24 times, compared with the Pd-decorated SnO2 nanofibers. This study provides optimum In2O3 nanoparticles with the best hydrogen sensing performance and sensing mechanisms.