Enhanced Sensing Ability of Brush-Like Fe(2)O(3)-ZnO Nanostructures towards NO(2) Gas via Manipulating Material Synergistic Effect

Brush-like α-Fe(2)O(3)–ZnO heterostructures were synthesized through a sputtering ZnO seed-assisted hydrothermal growth method. The resulting heterostructures consisted of α-Fe(2)O(3) rod templates and ZnO branched crystals with an average diameter of approximately 12 nm and length of 25 nm. The gas-sensing results demonstrated that the α-Fe(2)O(3)–ZnO heterostructure-based sensor exhibited excellent sensitivity, selectivity, and stability toward low-concentration NO(2) gas at an optimal temperature of 300 °C. The α-Fe(2)O(3)–ZnO sensor, in particular, demonstrated substantially higher sensitivity compared with pristine α-Fe(2)O(3), along with faster response and recovery speeds under similar test conditions. An appropriate material synergic effect accounts for the considerable enhancement in the NO(2) gas-sensing performance of the α-Fe(2)O(3)–ZnO heterostructures.