H-2, H2S gas sensing properties of rGO/GaN nanorods at room temperature: Effect of UV illumination

In this work, reduced graphene oxide (rGO)/GaN nanorods (NRs) hybrid structure based sensors for hydrogen (H-2) and hydrogen sulfide (H2S) gases has been demonstrated at room temperature. The morphological, elemental, and structural analyses were carried out by using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The electrical characterization of rGO/GaN NRs hybrid structures showed good rectifying behavior compared to pristine GaN NRs. The H-2 and H2S gas sensing measurements at different gas concentrations revealed that the rGO/GaN NRs exhibit superior sensing properties compared to pristine GaN NRs. In order to find the gas sensing mechanism of rGO/GaN NRs, hybrid structure sensor is also tested with NOx gas. Our experimental results revealed that the rGO/GaN NRs are good candidates for selective detection of H2S gas. The rGO/GaN NRs showed remarkably improved response under ultra-violet (lambda = 365 nm) illumination, the photogenerated carriers could be responsible for increasing response of the gas sensor at 30 C under UV illumination. In addition, humidity test of the rGO/GaN NRs sensor was also conducted in this work. Our experimental results suggested that decorating GaN NRs with solution-processable rGO is one of the effective ways to enhance the response of GaN nanostructures. (c) 2018 Elsevier B.V. All rights reserved.