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.