Rose-Like MoO₃/MoS₂/rGO Low-Temperature Ammonia Sensors Based on Multigas Detection Methods

Abstract

In order to improve the sensitivity of the pure MoO3 sensor to ammonia and reduce its operating temperature, MoO3/MoS2/rGO was prepared in this work, and the gas-sensitive performance of MoO3/MoS2/rGO was studied. The results of the static gas sensitivity test show that, compared with pure MoO3, MoO3/MoS2/rGO greatly improves the response of the sensor to ammonia at low temperature. Moreover, this article discusses the multigas detection methods by waveform-matched dynamic temperature modulation based on low-temperature gas sensor composites of rose-like MoO3/MoS2/rGO, which is used to solve the shortcoming of poor selectivity of metal–oxide–semiconductor gas sensor. Multigas (including acetone, methanol, ethanol, benzene, toluene, and ammonia) detection methods by waveform-matched dynamic temperature modulation are investigated, in which the experimental results show that the dynamic response curves of the sensor have obvious differences to each gas under different temperature waveform modulations. Temperature modulation waveforms with different periods and variations are investigated, including rectangular wave, triangular wave, and sine wave. This provides a feasible way to improve the selectivity of the sensor. In order to establish and verify the accuracy of the multigas detection model, 100 sets of response curves are selected for each waveform. Finally, the gas-sensing mechanism of gas-sensitive materials to ammonia is analyzed. Preparation of highly sensitive materials, dynamic testing, and gas identification methods can provide the technical basis for the application of gas sensors.