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

The imperative to detect acetone (CH 3 COCH 3 ) 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 CeO 2 (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 CeO 2 ) presents a remarkable response of 36.6 to 100 ppm acetone at 170℃, 15.3-fold superior to that of its pristine CeO 2 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 CeO 2 and Ag as well as Ta 2 O 5 and Ag. Meanwhile, density functional theory calculations affirm the STC sensors' predilection for high O 2 and acetone adsorption energy while maintaining low affinity to H 2 O molecules. These findings herald the potential of "U-shaped" groove heterojunction in advancing humidity-resistant gas sensors. ● The STC hollow nanofibers were fabricated by electrospinning and UV Irradiation. ● The STC gas sensors behave a humidity-resistant and remarkable response to acetone. ● The enhanced response can be attributed to Ta doping and Ag modification. ● Moisture resistance was due to hydrophobic Ag (110) and the "U-shaped" junction. ● DFT confirmed STC sensors' strong O 2 and acetone adsorption, and low H 2 O affinity.