Low-temperature ethanol gas-sensing performances of porous Ag-doped SnO2: Structure-performance correlation and mechanism insight

Ethanol gas detection is vital for industrial processes like brewing and biofuel production, and for safety in medical and transportation systems. However, the response and selectivity of tin dioxide (SnO 2 ) towards ethanol gas still exhibit serious limitations at relatively low temperatures. In this study, the porous Ag-SnO 2 composites were successfully synthesized by using sacrificial carbon nanotubes (CNTs) template-assisted hydrothermal synthesis, enhancing the sensitivity and selectivity towards ethanol gas. Specifically, Ag-SnO 2 nanoparticles were uniformly grown on the surface of CNTs via a hydrothermal method, followed by calcination to remove the CNTs, and obtained porous Ag-SnO 2 composites. The composites demonstrated excellent ethanol sensing characteristics: high response magnitude, excellent selectivity, good stability, and wide detection concentration range. The porous structure significantly increased surface area and gas adsorption of SnO 2 , while Ag doping enhanced surface catalytic activity. This work provides a promising approach for designing high-performance, low-temperature SnO 2 -based ethanol sensors.