H2S gas sensing enhancement of Au-decorated SnO2 nanospheres synthesized using hydrothermal and microwave methods

• Au-decorated SnO 2 nanospheres were synthesized using hydrothermal and microwave methods. • The SnO 2 spheres ranged from hundreds of nanometers to a microscale. • These gas sensing effects were approached by two disadvantage factors and five advantage factors. In this study, non-oriented Au-decorated SnO 2 nanospheres (NSs) were synthesized using hydrothermal and microwave methods. The SnO 2 spheres ranged from hundreds of nanometers to a microscale. The oxygen vacancy on the surface increased after Au adsorption on the surface of the SnO 2 NSs, ultimately showing a synergistic effect with the spillover effect of the existing Au catalyst. Specifically, at 100 °C and 200 °C, the response to 10 ppm H 2 S gas improved to 16.14 and 46.81, respectively. These gas sensing effects were approached individually by being divided into two disadvantages (oxygen adsorption and homojunction) and five advantages (oxygen vacancies, spill-over, surface area, H 2 S + SnO 2 reaction, and H 2 S + O 2 reaction). Based on this reference, we investigated SnO 2 NSs of various sizes and functions by adjusting the process variables.