Ordered Mesoporous SnO Micro Sheets Based Highly Sensitive and Selective Ethanol Gas Sensor

Abstract

Stannous oxide (SnO) micro sheets were successfully synthesized by the hydrothermal alkaline solution method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller (BET) techniques. BET analysis confirmed a mesoporous structure with 33.8944 m2 g−1 specific surface area and an average pore diameter of 6.488 nm. The resistance-based study of SnO was performed for the various volatile organic compounds (VOCs) at 100 °C. The response of the sensor is maximum toward ethanol with good response (∼2 s)/recovery (∼11 s) time at 100 °C. The optimum working temperature of the sensor was found to be 100 °C for ethanol gas. The response of the sensor typically depends on the surface state, gas diffusion, pore diameter, working temperature of the sensor, and crystallite size of the material. The crystallite size (29.251 nm) and strain (8.952 × 10−4) of the SnO particles were analyzed by Williamson-Hall Plot. The response of the target gases was validated by the Knudsen diffusion coefficient (D κ ). The D κ value for the ethanol gas was 8.962 × 1011 nm s−1 at 100 °C, which is the maximum among the obtained values of other VOCs.