Efficient, fast response, and low cost sensor for NH3 gas molecules based on SnO2: CuO/macroPSi nanocomposites

Abstract

In the present study, a procedure of the inserting of SnO2:CuO nanoparticles with different CuO nanoparticles contents within a macroporous silicon layer (macroPSi) gas sensor was prepared and successfully investigated. The macroPSi was effectively fabricated by laser assisted etching process, and CuO nanoparticles loaded with SnO2 with a high value of surface area were successfully synthesized by the spray pyrolysis method. Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FE-SEM) manifested a novel morphology for CuO Bucky particles inside the pores and a nano nail like structure for SnO2 with a small average grain size of CuO Bucky particles with 30% content. This morphology of nanocomposites improved the sensing performance for NH3 gas. A higher sensitivity with a very swift response and recovery times of 4 s and 55 s, respectively, was obtained with 150 ppm of NH3 gas at the room temperature. This improvement in gas sensor performance is strongly related to the higher specific surface areas and smaller particle size with a higher surface roughness of SnO2 and CuO nanoparticles within the nanocomposites.