Highly sensitive ethanol sensor based on self-assembled BiVO4 nanorod bundles

Resistive gas sensors utilizing nanostructured metal oxides (MOs) have garnered significant attention for their potential use in detecting volatile organic compounds (VOCs) due to their low cost, higher stability, and easy manufacturing. However, the prime factors that prevent practical applications of these sensors are the limited sensitivity, increased power consumption, and extended response recovery times which might originate from insufficient interaction between gas molecules and the nature of inherent active sites involving gas sensing reactions. To address these challenges, unique self-assembled BiVO4 (BVO) nanorod bundles were prepared via a hydrothermal reaction, and their application in ethanol sensing is reported. The as-synthesized BVO nanorod bundles sensor exhibited an ultrasensitive response (S = Ra/Rg) of 208.6–50 ppm ethanol at an optimal temperature of 170 °C and a response/recovery time (tres/trec) of 12/16 s. Furthermore, the sensor achieved a practical detection limit as low as 1 ppm, maintaining a swift response-recovery time. Notably, the sensor demonstrated excellent selectivity towards ethanol in the presence of interfering vapors (methanol, hexane, acetone, formaldehyde, and water) and exhibited remarkable stability over 30 days. The key factor contributing to the impressive gas sensing capability of the BVO nanorod bundles sensor is its well-controlled hierarchical morphology, which provides abundant active sites for efficient charge transfer and enhanced interaction with ethanol molecules. The ultrasensitive response of the BVO nanorod bundles sensor to ethanol, and significantly faster response-recovery times highlight its potential for ethanol monitoring in various industrial and environmental applications. [Display omitted] •Self-assembled BVO nanorod bundles are prepared through a hydrothermal strategy.•The nanorod bundle structure of BVO has been prepared to enhance ethanol sensing.•BVO has a high response (208.6) to 50 ppm ethanol with a fast response/recovery time (12/16 s).•Unique structure and enhanced interaction with ethanol enable superior sensitivity.