Single-Nozzle Flame Synthesis of Spinel Zn₂SnO₄ Nanoparticles for Selective Detection of Formic Acid

In this research, flame spray pyrolysis (FSP) was used to synthesize spinel Zn
₂
SnO
₄
nanoparticles for the first time based on the precisely designed stoichiometric chemistry of organic precursor solution driven through a single FSP nozzle. The characterization results based on X-ray diffraction, transmission electron microscopy and nitrogen adsorption confirmed the formation of spinel cubic Zn
₂
SnO
₄
phase with high phase purity and high specific surface area of 78.8 m
²
/g. The gas-sensing properties of Zn
₂
SnO
₄
sensors measured in dry air at 200-400 °C revealed high HCOOH selectivity against several other volatile organic acids, volatile organic compounds and environmental gases with a high and repeatable response of 16.5 towards 1000 ppm HCOOH at an optimal operating temperature of 350 °C.