Improved Ethanol Sensing Performance of α-MnO2 Nanorods at Room Temperature Enabled through PPy Embedding

Ethanol is a colorless, highly flammable, volatile organiccompoundand is a biomarker for fatty liver diseases. So, high-performanceand reliable ethanol sensors are the need of the day for biomedicaland environmental monitoring applications and drunken driving detection.In this work, we have reported a polypyrrole (PPy)-embedded & alpha;-MnO2 nanorod (NR)-based chemiresistive sensor for the selectivedetection of trace ethanol vapor at room temperature (25 & DEG;C).PPy-embedded & alpha;-MnO2 NR nanocomposites (MP25, MP50,and MP100) were synthesized by in situ chemical oxidative polymerizationof pyrrole followed by mixing of & alpha;-MnO2 NR havingdifferent weight ratios. The prepared nanocomposites were characterizedby various sophisticated instruments such as XRD, FTIR, Raman spectroscopy,BET, FESEM, TEM, EDX, UV-vis spectroscopy, and current-voltage(I-V) measurement. The as-preparedsensor, namely, PPy-embedded & alpha;-MnO2 nanorod (MP50),shows the highest response to ethanol vapor with a detection lowerlimit of 1 ppm at room temperature with rapid response (& SIM;2.39s) and recovery (& SIM;37.08 s) times associated with at least 60days stability, excellent selectivity, good repeatability, and reproducibility.The formation of a p-n heterojunction and transfer of chargecarriers between PPy and MnO2 nanoparticles are attributedto the enhancement of sensing performance. Thus, the prepared sensorcould be potentially applicable to detect ethanol content in alcoholicbeverages, diagnose liver disease from exhale breath analysis, anddrunken driving detection.