Graphene based Nano Gas Sensors: Mechanistic Study

In this study, graphene nanoribbons (GNBs) were utilized as a conductive agent for the olivine structure-based cathode LiFePO4 to facilitate the fast redox reaction and enable a high-rate battery performance. As a result, the cathodes comprising 5 wt% graphene nanoribbons and 10 wt% conductive carbon nanoparticles exhibited the maximum capacity, 163.25 mAh.g−1 at 0.1C and 130.60 mAh.g−1 at 2C with excellent capacity retention after 100 cycles. In addition, graphene nanoribbons demonstrate positive impacts on the charge transfer process. Still, the high concentration of GNBs in the cathode weakens the adhesion properties and will need further optimization in the slurry mixing process.

Enabling stable and high-rate of an olivine-type cathode LiFePO₄ for Li-ion batteries by using graphene nanoribbons as conductive agent

Nguyen¹,

Nguyen²,

Thai³

et al. 2023

Selective and reversible carbon mono oxide gas detection using silver doped octahedral molecular sieves (OMS-2) nanorods

Gupta,

Singh,

Jaiswal

et al. 2024

In this work a potable, resistive sensor is fabricated for the selective detection of CO gas using nanorods of Ag doped octahedral molecular sieves-2 (Ag-OMS-2). During exposure to carbon monoxide (CO) gas at room temperature, resistance of Ag-OMS-2 film was dropped from 557 kΩ to 352 kΩ in just 18 sec. However, exposed sample regained its initial resistance value in 25 sec when CO gas source was removed. Both sensing and recovery processes were carried out at room temperature. The sensor film showed excellent reproducibility during several cycles of CO gas exposure. Swift activation of oxygen molecules for the oxidation of CO by the silver present in the tunnel of manganese oxide network is supposed to be responsible for sensing activity of Ag-OMS-2 towards carbon monoxide gas.

Ultra-thin V₂O₅ nanowires: synthesis and gas sensing characteristics

Do,

Chu,

Nguyen

et al. 2024

This study presents the synthesis of vanadium oxide nanowires via a simple hydrothermal method and explores their potential as high-performance sensors for monitoring harmful gases, with a particular focus on NO2. The microstructure and morphology of the nanowires were characterized using scanning electron microscopy, powder x-ray diffraction, and Raman spectroscopy. The vanadium oxide nanowire material demonstrates outstanding NO2 gas sensing capabilities, detecting 5 ppm with a rapid response and high sensitivity at an optimal working temperature of 150 °C. It exhibits a relative resistance change of 70%, showcasing a sub-ppm detection limit. The V2O5 nanowires exhibited good stability and high gas selectivity for NO2 over other interfering gases (H2S, NH3, C2H4, and CO). The ultrathin structure of the nanowires holds promise for practical applications in developing NO2 gas sensors. The study sheds light on the superior sensitivity of the V2O5 gas sensor toward NO2 at low temperatures, emphasizing the influence of the 1D structure on the sensing mechanism.