SAIP2026

Room temperature trace Acetone detection using W18O49-WO3 nanostructures

8 Jul 2026, 10:10

20m

Lecture Hall GH1 (University of the Western Cape)

Oral Presentation Track A - Physics of Condensed Matter and Materials Physics of Condensed Matter and Materials

Speaker

Jodinio Lemena (University of the Free State)

Description

We report the room-temperature (RT) detection of trace-level acetone using a W₁₈O₄₉-based gas sensor incorporating a minor secondary WO₃ phase. The sensing material was synthesized using the solvothermal method, yielding nanoparticles along with sparsely separated nanorods as photographed using SEM and TEM instruments. The intrinsic properties (i.e., crystal structure, and defect states) of the W18O49 /WO3 were examined using characterization techniques such as PXRD, PL, UV-vis and XPS. The sensor was exposed to a minimal concentration of 0.08 ppm acetone, leading to a response (Ra/Rg) of 1.04, while at 1.8 ppm, the response was 1.49, respectively. This performance ranks among the best W18O49 based acetone sensors which exclusively operated at high temperatures. Relative humidity (RH) measurements revealed that the sensor thrived in humid conditions, which to the best of our knowledge is novel with regard to W18O49 based sensors. Selectivity analysis of the W₁₈O₄₉-based gas sensor revealed superior sensing performance toward acetone compared to the six other tested analytes, namely ethanol, methanol, m-xylene, p-xylene, o-xylene, and benzene. The sensor response data was analyzed using PCA and kNN. PCA revealed clearly separated clusters for different gases, showing distinct response patterns. The combined PCA-kNN approach achieved 93% accuracy, demonstrating strong capability in distinguishing acetone from other VOCs. This highlights the benefit of combining nanostructured W18O49 sensing materials with Machine-Learning tools for reliable VOC detection in complex environments.