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

Abstract

Sea urchin-like Ag–α-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–α-Fe₂O₃ nanocomposite microspheres with enhanced gas-sensing properties in comparison to pristine α-Fe₂O₃ sensors. The possible formation mechanism of the sea urchin-like nanostructures, and their sensing mechanism are discussed.