Sea urchin-like Ag-alpha-Fe2O3 nanocomposite microspheres: synthesis and gas sensing applications

Sea urchin-like Ag-alpha-Fe2O3 nanocomposite microspheres are developed for gas sensing applications. Such hierarchical nanostructures were synthesized by a two step approach including a hydrothermal reaction and a subsequent incipient wetness impregnation process. The large Brunauer-Emmett-Teller (BET) area and highly porous structure of the hierarchical architecture and the chemical and electronic sensitization effect of Ag nanoparticles endow the Ag-alpha-Fe2O3 nanocomposite microspheres with enhanced gas-sensing properties in comparison to pristine alpha-Fe2O3 sensors. The possible formation mechanism of the sea urchin-like nanostructures, and their sensing mechanism are discussed.