Well-designed g-C <sub>3</sub>N <sub>4</sub> nanosheet incorporated Ag loaded Er <sub>0.05</sub>La <sub>0.95</sub>FeO <sub>3</sub> heterojunctions for isoamyl alcohol detection
Kaichun Xu, Mengjie Han, Zichen Zheng, Zexin Yu, Hanlin Liao, Hui Sun, Chao Zhang
Abstract
Considering that the volatile content of isoamyl alcohol will increase sharply on the seventh day during wheat mildew, isoamyl alcohol can be determined as an early biomarker of wheat mildew. Currently, there are only few sensors reported for isoamyl alcohol detection, which still suffer from low sensitivity and poor moisture resistance. Herein, the sensitivity of 5 at% Er@LaFeO<sub>3</sub> (ELFO) for isoamyl alcohol was enhanced by loading Ag nanoparticles on the surface of the ELFO microspheres while the optimal operating temperature was reduced. The moisture resistance of Ag/ELFO was improved by the incorporation of g-C<sub>3</sub>N<sub>4</sub> nanosheets (NSs) on the surface of Ag/ELFO through electrostatic self-assembly. Given the requirement of practical application in grain granaries, the sensing behavior of g-C<sub>3</sub>N<sub>4</sub> NSs incorporated Ag/ELFO-based sensor at 20% RH was systematically studied, which demonstrated excellent repeatability, long-term stability, and superior selectivity (791 at 50 ppm) for isoamyl alcohol with a low limit of detection (LOD = 75 ppb). Furthermore, the practical results of wheat at different mildew stages further confirmed the application potential of the g-C<sub>3</sub>N<sub>4</sub>/Ag/ELFO-based sensor in monitoring the early mildew stage of wheat. This work may offer guidance for enhancing the moisture resistance of gas-sensitive materials through the strategy of employing composite nanomaterials.