Dual-Motor Oxygen-Deficiency-Engineering Al-Doped W<sub>18</sub>O<sub>49-<i>x</i></sub> Circular Nanorod Arrays for Parts per Billion-Level Acetone Detection.

Hu, Jinwu; Jin, Lin; Kou, Huirong; Li, Hui-Jun; Xu, Jingcheng; Hu, Qingmin; Li, Guisheng; Wang, Ding · Nano Lett · 2025

basic_science · Level V

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Abstract

Developing low-temperature gas sensors for parts per billion-level acetone detection in breath analysis remains challenging for non-invasive diabetes monitoring. We implement dual-defect engineering via one-pot synthesis of Al-doped W<sub>18</sub>O<sub>49-<i>x</i></sub> nanorod arrays, establishing a W-O<sub>v</sub>-Al catalytic mechanism. Al<sup>3+</sup> doping induces lattice strain to boost oxygen vacancy density by 31.74% while transforming passive O<sub>v</sub> sites into active centers that enhance α-chemisorbed oxygen capacity and accelerate O<sub>2</sub> dissociation into reactive O<sup>-</sup> species. This synergy strengthens acetone adsorption (density functional theory-confirmed adsorption energy of -1.607 eV) and directs selective oxidation to acetic/formic acid. Consequently, the Al-W<sub>18</sub>O<sub>49-<i>x</i></sub> sensor demonstrates exceptional performance, including a maximum response of 65-50 ppm of acetone at 200 °C, an ultralow limit of detection (LOD) of 10 ppb, and remarkable long-term stability and durability, highlighting its potential for clinical diabetes diagnosis. Integrated with machine learning algorithms, it successfully discriminates healthy and simulated diabetic breath, enabling non-invasive clinical screening.