Experimental and theoretical studies on noble metal decorated tin oxide flower-like nanorods with high ethanol sensing performance

This study reports a facile solvothermal method for the synthesis of tin oxide (SnO₂) flower-like nanorods with dominant (1 1 0) crystal surface, which could be further decorated with varying amounts of noble metals, (gold (Au) and palladium (Pd)) to enhance the gas-sensing properties. Analysis of the gas-sensing results reveal that the decoration of Au and Pd nanoparticles on the surface of the SnO₂ nanorods is advantageous in: (i) enhancing the sensitivity towards ethanol (9-15 times); (ii) reducing the response/recovery time (by 15-40 s), and (iii) significantly decreasing the optimum operating temperature (from 250 to 175 degrees celcius). Beyond physical experiments, molecular dynamics (MD) method was also conducted to quantify diffusivity, adsorption and reaction capabilities of ethanol on SnO₂(1 1 0) plane and to better understand the role of noble metals in enhancing the gas-sensing performance of SnO₂. The findings in this study will be useful for future design of metal oxide nanocomposites with specific crystal surface for achieving high performance in surface-governed applications.