Influence of en-APTAS membrane on NO gas selectivity of HfO2-based memristor gas sensors

Abstract

Memristor-based gas sensors (gas sensor + memristor, gasistor) have gained popularity due to their high response characteristics and ability to operate at RT. In this paper, N-[3-(Trimethoxysilyl)propyl]ethylenediamine (en-APTAS), a commonly used membrane for NOx gas sensors, is applied in the gasistor with carbon nanotubes (CNTs)-top electrode (TE). As a result, we have demonstrated the response time was reduced by 104 s, and the response to 10 ppm Nitric oxide (NO) gas increased to 3.69, indicating an enhanced sensing property in a range of 10-50 ppm. Furthermore, when decorated with the proposed en-APTAS, the gasistor with CNTs-TE demonstrated a 3.76-fold increase in response to NO gas compared to NO2 gas, demonstrating remarkable selectivity. These improved features are attributed to the high adsorption energy of en-APTAS and the large kinetic diameter of NO2. The research proposal will be a foundational stage towards attaining selectivity in other gasistor studies.