Selective Sensing of Gas Mixture via a Temperature Modulation Approach: New Strategy for Potentiometric Gas Sensor Obtaining Satisfactory Discriminating Features

Abstract

A new strategy to discriminate four types of hazardous gases is proposed in this research. Through modulating the operating temperature and the processing response signal with a pattern recognition algorithm, a gas sensor consisting of a single sensing electrode, i.e., ZnO/In2O3 composite, is designed to differentiate NO2, NH3, C3H6, CO within the level of 50–400 ppm. Results indicate that with adding 15 wt.% ZnO to In2O3, the sensor fabricated at 900 °C shows optimal sensing characteristics in detecting all the studied gases. Moreover, with the aid of the principle component analysis (PCA) algorithm, the sensor operating in the temperature modulation mode demonstrates acceptable discrimination features. The satisfactory discrimination features disclose the future that it is possible to differentiate gas mixture efficiently through operating a single electrode sensor at temperature modulation mode.

Micromachined Thermal Gas Sensors—A Review

“…A review of semiconductor gas sensor literature pertaining to the use of temperature modulation techniques can is given by Lee and Reedy [ 125 ]. Investigation into this area has continued and some more recent examples can be found here [ 126 , 127 , 128 ].…”

ZnO Nanowire Application in Chemoresistive Sensing: A Review

“…While, in biosensors, different analytes can be targeted with a special biomolecule, it is an especially difficult task to differentiate among the same type of gases (oxidizing or reducing), since depletion layer width change and consequently response will be in the same direction. Selective recognition of the gases can be addressed by variations in chemical adsorption and dissociation of the target gases at the NW surface; therefore, NW sensor selectivity can be approached by several methods: NW geometry control [ 36 , 37 ], NW functionalization [ 38 , 39 ], selective contact formation [ 40 ], heterojunction [ 41 ], operating temperature modulation [ 42 ], and sensor array formation [ 43 ].…”