Surface Modification of CuFe2O4 Nanotubes with Well-Dispersive Au Nanoparticles for Sensitive and Selective Xylene Gas Detection

Au-modified CuFe2O4 nanotubes (Au-CuFe2O4 NTs) were synthesized through a combination of electrospinning and liquid precipitation methods, resulting in the uniform surface modification of well-dispersive Au nanoparticles (NPs) with an average diameter of 3.4 nm. Gas-sensing results demonstrated that the Au-CuFe2O4 sensors (0.5–5 wt % Au) exhibited significantly enhanced responses to xylene gas. Specifically, the 2 wt % Au-modified sensor displayed the highest response (38.1 @ 100 ppm xylene) and excellent selectivity at 260 °C. The comprehensive influences of ambient humidity and Au content on the detection capability of xylene using Au-CuFe2O4 NTs were discussed systematically. The superior activity of Au-modified sensors compared to pristine CuFe2O4 NTs was confirmed by their improved recovery characteristics in the presence of a high concentration of xylene. These enhanced sensing performances can be mainly attributed to electronic sensitization of Au and the synergistic catalytic effect of Au and CuFe2O4, indicating the great potential of Au-CuFe2O4 NTs for sensitive and selective xylene detection.