Chiang Mai Journal of Science

       In this work, effective gas-sensing material were prepared by combining spinel zinc stannate (Zn₂SnO₄) nanoparticles synthesized by flame spray pyrolysis and graphene produced by the electrolytic exfoliation for volatile organic acids (VOAs) detection. The effect of graphene content in the range of 0.2–5 wt% on formic acid (HCOOH)-sensing performance of Zn₂SnO₄ nanoparticles was evaluated. Structural, physical, and chemical properties were investigated using X-ray diffraction, Raman spectroscopy, BET-surface analysis, energy dispersive X-ray spectroscopy, and electron microscopy. From the gas-sensing test towards 0.005-0.1 vol% HCOOH in dry air at 200-400°C, the graphene-loaded Zn₂SnO₄ sensor with the optimal graphene content of 0.5 wt% displayed the highest response of ~4970 towards HCOOH at the optimal temperature of 300°C. Moreover, it showed high HCOOH selectivity against several other VOAs, volatile organic compounds, and environmental gases. Therefore, graphene-loaded spinel Zn₂SnO₄ sensors could be attractive choices for selective HCOOH detection and useful for food science and industrial applications.