Ammonia Sensing Performance of RGO-Based Chemiresistive Gas Sensor Decorated With Exfoliated MoSe₂ Nanosheets

Abstract

Chemiresistive ammonia gas sensor based on Reduced graphene oxide (RGO) is an excellent alternative for developing low-cost chemiresistive ammonia gas sensors. However, pure RGO based devices have several disadvantages associated with it such as the response of these devices are very low and the response and recovery time is significantly high. In this work, we have demonstrated that loading MoSe ₂ nanosheets on RGO sheets helps in improving its ammonia sensing capabilities significantly. The RGO/MoSe ₂ nanocomposite showed limit of detection down to 300 ppb, whereas, pure RGO based sensor couldn't reliably measure concentration below 1 ppm. The responsivity of nanocomposite-based sensor was 2.6 times better compared to pure RGO sensor. The sensor device could be operated at room temperature with an operating voltage of 2 mV, which demonstrated ultra-low power consumption compared to other commercially available metal oxide Taguchi sensors or electrochemical sensors. A sensing mechanism based on charge transfer is proposed to elucidate the better performance for the device.