Memristive Gas Sensor Based on TiO2 Nanosheets for Triethylamine Detection at Room Temperature

Abstract

To avoid the threat caused by triethylamine (TEA), the development of gas sensors with high sensitivity to TEA vapor is inevitable. However, the room temperature (RT) sensitivity and recovery performance of current metal oxide-based TEA sensors need to be further improved. Herein, a memristive gas sensor (gasistor) based on a sandwich structure was proposed, and the resistive layer was designed as TiO₂ nanosheet (NS) structure to balance the resistive switching and gas-sensitive performance. Compared to the TiO₂ film-based sensor with the same sensitive structure, the developed Ag/TiO₂ NSs/FTO gasistor exhibited the advantages of RT sensitivity, better selectivity, and tunable recovery. It was observed that the gasistor showed a high response of ∼26.45 to 1 ppm TEA vapor at RT when set to the high resistance state, and the gas selectivity for TEA was also enhanced. Interestingly, a rapid recovery of ∼1.9 s was achieved by introducing a scanning voltage to the device. Moreover, first-principles calculations were combined to understand the adsorption energy, charge transfer, and the electronic structures at the atomic scale, elucidating the adsorption behavior of gas molecules on the TiO₂ (001) surface in different states. The present work brings an idea to enhance the performance of metal oxide-based gas sensors.