NO₂ detection and redox capacitance reaction of Ag doped SnO₂/rGO aerogel at room temperature

A new material of Ag-SnO₂/rGO aerogel is fabricated by the sol-gel method and freeze-drying technique. The SnO₂ particles are tightly arranged on the rGO sheets to form a p-n heterojunction, and the rGO aerogel possesses abundant pore structures for effective adsorption. Besides, the Ag particles are dispersed on the surface as a catalyst to improve the internal electron mobility, further promoting the gas-sensing performance. To be noted, the Ag-SnO₂/rGO aerogel can exhibit a response of 2.13 towards 50 ppm NO₂ at RT instead of heating conditions, and shows a cyclic capacitance property of redox. Moreover, the non-linear growth between gas concentration and response is observed, which proves the chemical adsorption that results in the high selectivity.