Mo₂C/MoO₃@rGO Ternary Nanocomposites as High-Performance Gas Sensor for Trace NH₃ Detection at Room Temperature

Abstract

Mo 2 C/MoO 3 @rGO ternary nanocomposites were synthesized by a hydrothermal method, which can be applied to the high-sensitivity detection of low concentration of NH 3 at room temperature. Compared with pure MoO 3 and MoO 3 @rGO sensors, the Mo 2 C/MoO 3 @rGO sensors showed a significantly improved response to NH 3 at room temperature. Among them, the 6% Mo 2 C/MoO 3 @rGO sensor showed a response of up to 0.82 for 5 ppm of NH 3 with a response time of 87 s, which was 27.33 times higher than that of pure MoO 3 (0.03 in 154 s) and 5.86 times higher than that of MoO 3 @rGO (0.14 in 139 s). It also has high repeatability, selectivity, good long-term stability, and immunity to humidity. These optimizations of the gas-sensing properties of the material may be attributed to the ability of the heterojunction to modulate the material surface carriers, the chemical sensitization and good electrocatalytic ability of Mo 2 C, and the large specific surface area and high carrier mobility of rGO. The synergistic effect between these three materials allows the designed Mo 2 C/MoO 3 @rGO ternary composite to detect trace amounts of NH 3 at room temperature, making it possible to develop high-performance NH 3 gas sensors.

A proposed device based on MoSe2-ZnO heterojunctions on rGO for enhanced ethanol gas sensing performances at room temperature

“…In order to further strengthen the sensing performance of 2D TMDs-MOS hybrids, researchers are focussing on compositing them with carbon materials forming a ternary nanocomposite [24,25]. In comparison to the binary hybrids, ternary nanocomposites develop multiple heterojunctions which modulate the charge transfer behavior in the gas sensing process thereby enhancing the sensing performance of the ternary nanocomposite sensors [26,27]. Carbon materials such as reduced-graphene oxide (rGO) have been employed in the field of gas sensing owing to the presence of abundant residual oxygen functional groups, superior specific surface area, high carrier mobility, and chemically active defect sites for the adsorption of gases [4,24,[28][29][30].…”