Potassium Trimolybdates as Potential Material for Fabrication of Gas Sensors

The increased growth in industrialization has led to emission of hazardous gases. In order for humans to have a safe and secure well-being, the concentrations of toxic gas need to be monitored. Chemiresistive gas sensors are pivotal elements in the group of gas sensors. Nanowires of molybdates with K+ group (K2Mo3O10.4H2O), grown using the chemical method, possess potential as exceptionally sensitive gas-sensing materials at room temperature. The isolated nanowires are resistive gas sensorswere fabricated for sensing toxic gases in a lower concentration using the dielectrophoresis technique. Exposure to low concentrations of different vapors at room temperature indicates larger selectivity toward NH3. The static response for concentration below the toxic limit of NH3 shows a speedy response and recovery-to-base value. The lowest concentration detectable using the sensor is 500 ppb. Linear response of sensitivity variation with concentration is seen for concentrations ranging from 500 ppb to 12.5 ppm. The plausible mechanism behind the sensitivity lies in functional characteristics of isolated nanowires. Gas adsorption and charge transfer reactions are swift with the isolated nature of nanowires. The surface structure possesses oxide and hydroxyl, giving rise to abundant free electrons available for charge transfer reactions. The adsorption kinetics of NH3 play a major role behind larger sensitivity.