Boron nitride nanotubes (BNNTs) decorated Pd-ternary alloy (Pd63.2Ni34.3CO2.5) for H2 sensing

The micro-electro-mechanical system (MEMS)-based field effect transistor (FET) sensor for hydrogen detection was fabricated by modifying the gate electrode with boron nitride nanotubes (BNNTs) decorated Pd-ternary alloy (Pd63.2Ni34.3Co2.5) as a hydrogen sensing layer Electro-thermal properties of the micro-heater embedded under sensor membrane were analyzed by a finite element method (FEM) simulation. The structural and morphological properties of the gate electrode were studied by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM). A variation in gate potential is observed due to the H-2 atmosphere that leads to the variation in the depletion region, therefore, changing the current in the channel (BNNTs decorated Pd-ternary alloy). The BNNTs-decorated Pd ternary alloy displayed high sensing response, fast response and recovery time for H-2 gas, low power consumption, long-term stability, and wide detection range from 1 to 5000 ppm H-2. The drain current of the H-2 FET sensor varied significantly at hydrogen gas exposure and increased with H-2 concentration. As proposed H-2 FET sensor can be utilized to the H-2 leak detection system for safe applications. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The MEMS-based FET hydrogen sensor utilizes a gate electrode modified with BNNTs-decorated Pd ternary alloy as a hydrogen sensing layer, demonstrating high sensitivity, fast response and recovery time, low power consumption, long-term stability, and a wide detection range. Analysis of the drain current variations at different H-2 concentrations confirms the sensor's potential for H-2 leak detection applications.