Efficient room temperature hydrogen gas sensing based on graphene oxide and decorated porous silicon

In this study, a triple system for a hydrogen gas sensor was fabricated using graphene oxide, palladium nanoparticles, and porous silicon as a substrate. The fabricated sample was investigated by energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, and Raman spectroscopy. Field emission scanning electron microscopy images displayed a relatively uniform distribution of Palladium nanoparticles over porous silicon. In addition, it was observed that the graphene oxide nanosheets accumulated over the Palladium nanoparticles. Hydrogen-sensing measurements demonstrated that the fabricated system can even detect hydrogen at 200 ppm and 15 °C. The formation of palladium hydride was the main mechanism for detection. In fact, this structure caused a change in resistance through the creation of new electron pathways. Furthermore, the H2 concentration showed a linear function to the reciprocal of the response time; this suggests that the sensing kinetics of the sample depends on the atomization of hydrogen molecules, which occurs via Pd nanoparticles. Moreover, the fabricated sample displayed significant selectivity for hydrogen gas compared to other examined gases.