Over the last decade, graphene's exceptional properties have revolutionized diverse fields with applications spanning electronics, materials science, energy storage, gas sensing and biotechnology (Castro Neto et al [1]). Graphene oxide (GO), derived from graphene has gained significant attention in the field of gas sensing due to its exceptional electrical, chemical and mechanical properties (Ma et al [2], Klechikov et al [3]). Modified Hummer’s method of GO synthesis is a well-known protocol wherein sonication, a powerful dispersion technique, is employed to exfoliate and functionalize GO sheets. Sonication provides the necessary energy to facilitate separation of bulk graphite oxide into thin, single- or few-layered GO nanosheets (Bera et al [4]). In this study, six GO samples synthesized at varying sonication times (5–120 min) have been investigated for H2 and SO2 gas sensing and their response characteristics were analyzed. The application of ultrasonic energy, leading to shear forces, reducing the lateral size of GO flakes, thus producing more uniform nanosheets, is clearly discernible. Characterizations including XRD, Raman, FTIR, TEM and UV-vis are shown to support the control influenced by sonication vis-à-vis reduction of particle size and control of flake morphology. Maximum gas sensing response characteristics were observed for GO sample that has been sonicated for 90 min. A fragmentation of the GO nanosheet along the a-axis is clearly discernible for sonication times greater than 60 minutes. It facilitates enhancement of the gas sensing response characteristics for both the gases.
