Surface bound nanostructures of ternary r-GO / Mn3O4/V2O5 system for room temperature selectivity of hydrogen gas

Room temperature detection of highly sensitive Hydrogen (H-2) gas sensing material preparation was taken as a major objective in this present work. Herein, a novel one pot hydrothermal method is proposed for the synthesis of ternary r-GO decorated Manganese oxide (Mn3O4) and Vanadium pentoxide (V2O5) nanocomposite. The significant electrical conductivity of r-GO plays an important role here to enhance the sensing property. Tunable band bending features of metal oxides over the r-GO surface makes the composite works at room temperature with high selectivity of H-2. The optical, structural and morphological characteristics were analyzed by UV-Visible spectroscopy (UV-Vis), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray Photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), and High Resolution-Transmission Electron Microscope (HR-TEM). The sensing results reveals that the present nanocomposite is selectively sensitive towards H-2 with sensitivity value of (175%) at room temperature with response time (82 s) and recovery time (92 s). To investigate the low detection limit gas concentration was varied in the range from 20 ppm to 50 ppm. The synergetic sensing performance and stability of this nanocomposite could be due to the formation of metal oxides with perspicuous nanostructures as heterojunction decorated over the r-GO stack layer.