Toward agricultural ammonia volatilization monitoring: A flexible polyaniline/Ti_3C_2T_x hybrid sensitive films based gas sensor

摘要

The monitoring of ammonia (NH_3) produced in agricultural fields is of great importance due to its huge threat to ecological environment and human health, yet routine monitoring technologies rely on manual completion and complex agricultural environment brings great challenges to the application feasibility of gas sensors. Herein, a flexible chemiresistive gas sensor based on polyaniline (PANI)/Ti_3C_2T_x hybrid sensitive films is developed toward agricultural NH_3 volatilization monitoring. The hybrid film was deposited on the flexible polyimide substrate by an in-situ self-assembly method. The sensor shows high sensitivity, low detection limit, excellent repeatability, high selectivity and good air stability, which could be attributed to the gas-sensing enhancement effects of PANI/Ti_3C_2T_x Schottky junction and improved protonation degree of PANI in the hybrids. Especially, the sensor exhibits excellent NH_3-sensing properties to 20-80 % relative humidity (RH) environments at a temperature range of 10-40 °C, making it promising for practical agricultural applications. Furthermore, the application feasibility of the sensor to ammonia volatilization monitoring is verified through agricultural simulation experiments. This work provides a fast and accurate gas sensor methodology toward unattended agricultural application, which is an important supplement to the existing technical methods and may greatly pushes forward the development of modernized intelligent agriculture.