RGO/WO₃ hierarchical architectures for improved H₂S sensing and highly efficient solar-driving photo-degradation of...

Surface area and surface active sites are two important key parameters in enhancing the gas sensing as well as photocatalytic properties of the parent material. With this motivation, herein, we report a facile synthesis of Reduced Graphene Oxide/Tungsten Oxide RGO/WO₃ hierarchical nanostructures via simple hydrothermal route, and their validation in accomplishment of improved H₂S sensing and highly efficient solar driven photo-degradation of RhB Dye. The self-made RGO using modified Hummer's method, is utilized to develop the RGO/WO₃ nanocomposites with 0.15, 0.3 and 0.5 wt% of RGO in WO₃ matrix. As-developed nanocomposites were analyzed using various physicochemical techniques such as XRD, FE-SEM, TEM/HRTEM, and EDAX. The creation of hierarchic marigold frameworks culminated in a well affiliated mesoporous system, offering efficient gas delivery networks, leading to a significant increase in sensing response to H₂S. The optimized sensor (RGO/WO₃ with 0.3 wt% loading) exhibited selective response towards H₂S, which is ~ 13 times higher (R_a/R_g = 22.9) than pristine WO₃ (R_a/R_g = 1.78) sensor. Looking at bi-directional application, graphene platform boosted the photocatalytic activity (94% degradation of Rhodamine B dye in 210 min) under natural sunlight. The RGO's role in increasing the active surface and surface area is clarified by the H₂S gas response analysis and solar-driven photo-degradation of RhB dye solution. The outcome of this study provides the new insights to RGO/WO₃ based nanocomposites' research spreadsheet, in view of multidisciplinary applications.