Susceptible CoSnO3 nanoboxes with p-type response for triethylamine detection at low temperature

Abstract

Ternary metal oxides containing two different metal cations are highly promising candidates for sensor materials due to their intriguing properties. Herein, we report on the application of CoSnO₃ nanoboxes with a porous structure as a sensing layer for highly sensitive detection of triethylamine at a relatively low temperature. The CoSnO₃ nanoboxes are obtained by calcination of CoSn(OH)₆ precursors derived from a solution precipitation method. The dosage of cobalt is found to strongly influence the structure of the products and the sensing properties. The morphological structure and chemical composition of the materials are investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N₂ adsorption–desorption and X-ray photoelectron spectroscopy. Gas sensing measurements demonstrate that the CoSnO₃ nanoboxes exhibit a p-type response and can efficiently detect triethylamine at a low temperature of 100 °C with a limit of detection of 134 ppb. The gas sensing mechanism is discussed by the modulation of a hole accumulation layer (HAL) on the adsorption of gas molecules.