Enhancement of SnO2 sensitivity to acetone by Au loading: An application of Evans–Polanyi principle in gas sensing

Acetone gas sensitivity enhancement by gold loading on tin dioxide surface pyramids using density functional theory is discussed in the present work. Arrhenius equations are used with suitable parametrization to represent the different structures. Thermal energies, such as Gibbs free energy and enthalpy, are used to obtain the response of different structures. Evans–Polanyi principle is used to extract the activation energies of the different structures from enthalpies of the reaction. Temperature variation of reaction rate with different Au concentrations is shown. Peak theoretical response agrees with the experiment. Sigmoid functions are used to represent the burning of acetone as it reaches its autoignition temperature. The variation of reaction rate, response time, and recovery time with acetone gas concentration is calculated and compared with available experimental data. Au decorated SnO2 pyramid cluster has a shorter response time than pristine SnO2.