Formation of nanograined Ag-Co3O4 core@shell structure to achieve enhanced xylene sensing characteristics

Xylene (C8H10) is a volatile organic compound as well as a pollutant which needs to be detected for various demands and applications. Herein, we report a unique core@shell (C-S) structure with core noble metal particles to incorporate catalytic elemnts. A nanograined Ag-Co3O4 C-S structure was prepared using a chemical synthesis method. Systematic xylene sensing studies were undertaken to prove the excellence of nanograined C-S structure. Various characterization techniques were used to confirm the synthesis of desired products with the expected features. The pristine sensor offered the highest performance to xylene at 350 °C, whereas nanograined Ag-Co3O4 C-S structure gas sensor worked at a lower temperature namely 250 °C. In addition, the maximum response of the pristine sensor to 50 ppm-xylene was about 1.26, whereas that of the nanograined Ag-Co3O4 C-S structure gas sensor was 2.47. Moreover, the latter sensor showed higher selectivity to xylene than the former sensor. The improved xylene sensing characteristics of the nanograined Ag-Co3O4 C-S structure gas sensor were caused by its high surface area, formation of Ag-Co3O4 heterojunctions, and catalytic effects of Ag nanoparticles. This study demonstrates the potential of this new system for sensing of xylene.