Enhanced Sensing Ability of Brush-Like Fe2O3-ZnO Nanostructures towards NO2 Gas via Manipulating Material Synergistic Effect

Abstract

Brush-like alpha-Fe2O3-ZnO heterostructures were synthesized through a sputtering ZnO seed-assisted hydrothermal growth method. The resulting heterostructures consisted of alpha-Fe2O3 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 alpha-Fe2O3-ZnO heterostructure-based sensor exhibited excellent sensitivity, selectivity, and stability toward low-concentration NO2 gas at an optimal temperature of 300 degrees C. The alpha-Fe2O3-ZnO sensor, in particular, demonstrated substantially higher sensitivity compared with pristine alpha-Fe2O3, along with faster response and recovery speeds under similar test conditions. An appropriate material synergic effect accounts for the considerable enhancement in the NO2 gas-sensing performance of the alpha-Fe2O3-ZnO heterostructures.