Harnessing Ag-decorated electrospun Ta-doped CeO2 nanofibers for superior acetone detection with unparalleled humidity resistance

Abstract

The imperative to detect acetone (CH₃COCH₃) in the absence of humidity interference is underscored by its expansive utility in environmental and healthcare contexts. To address this, a novel sensor comprising Ag-decorated Ta-doped CeO₂ (STC) hollow nanofibers has been engineered through a meticulous process of electrospinning, followed by the decoration of Ag nanoparticles via UV irradiation. The fabricated STC-2 sensor (1 mol% Ag @ Ta-doped CeO₂) presents a remarkable response of 36.6 to 100 ppm acetone at 170℃, 15.3-fold superior to that of its pristine CeO₂ counterpart, fast response time (19.53 s), exceptional selectivity, repeatability, and long-term stability. Impressively, the STC-2 sensor maintains a considerable response of 2.0 to acetone even at a minimal level of 0.5 ppm, with the theoretical lowest of detection limit of 9.9 ppb. In addition, the STC-2 sensor is resistant to moisture, attributed to the hydrophobic Ag (110) nanoparticles and the innovative "U-shaped" groove heterojunction which forms a potential barrier between CeO₂ and Ag as well as Ta₂O₅ and Ag. Meanwhile, density functional theory calculations affirm the STC sensors' predilection for high O₂ and acetone adsorption energy while maintaining low affinity to H₂O molecules. These findings herald the potential of "U-shaped" groove heterojunction in advancing humidity-resistant gas sensors.