Synthesis and structural characteristics of AgxSn1- xO2 nanocomposites and their sensing performance toward methane, hydrogen, and carbon monoxide

The physical features and potential applications of metal oxide semiconductor nanomaterials can be influenced by doping, heat treatment, and applied synthesis techniques. Herein, a simple hydrothermal method was used to synthesize AgxSn1- xO2 nanocomposites ( x =0, 0.05, 0.2, 0.4, 0.5, and 1). The crystal structure, surface morphology, chemical bonding, surface area, and oxidation states are investigated. FTIR, XRD, HR-TEM, SEM, and XPS techniques were used to characterize the AgxSn1- xO2 nanocomposites, while the electrical resistivity measurement was conducted to assess their gas-sensing characteristics. The findings demonstrate that Ag atoms are evenly distributed inside the tetragonal SnO2 lattice up to x =0.4, meanwhile, a further increase in x leads to the growth of a cubic Ag2O phase alongside the SnO2 phase. The crystallite size of the SnO2 phase was increased as the Ag concentration increased, whereas reduced for the Ag2O phase. The pure SnO2 phase exhibits spherical nanoparticles, whereas the AgxSn1- xO2 nanocomposites ( x > 0) have a morphology of nanosheets and nanoplates. The average BET surface area was improved to 358 m(2) /g by increasing the Ag content up to x =0.2. The XPS confirms the presence of various oxides such as Sn 3d, O 1 s, and Ag 3d. The AgxSn1- xO2 nanocomposites were employed as electrical sensors to detect CH4 , H-2 , and CO gases at an operating temperature range of 200-400 degrees C. The Ag0.2Sn0.8O2 nanocomposites show the best response/recovery time towards CH4 at 200 degrees C. The AgxSn1- xO2 composite exhibits a good response towards CH4 compared to H-2 , and CO gases.