Electrochemical sensor to environmental pollutant of acetone based on Pd-loaded on mesoporous In2O3 architecture

In this work, a series of Pd sensitized mesoporous In2O3 nanocomposites with 1.0, 1.5 and 2.0 mol% Pd-loading amount were obtained by a green and facile precipitation method, and evaluated their gas sensing properties as compared to pristine In2O3. According to the results of comparative sensing performance tests, the gas sensor based on 1.5 mol% Pd-loaded In2O3 displays prominent sensitivity and selectivity in sensing acetone vapor with superior response (similar to 82 with 50 ppm) and fast response (6 s), on account of the special porous structure possessing rich active sites and large surface area. The contact between Pd and In2O3 form a Schottky junction since Pd metal act as electron acceptor, a withdrawal of electrons from In2O3 by Pd metal lead to the decreased number of electron charge carriers. Therefore, the baseline resistance in air for 1.5 mol% Pd@In2O3 sensor greatly enhanced, as a result it shows ultra-high response. This work will give some clue to the researchers for the further development of n-type based sensors.