Ultrasensitive xylene sensor based on RuO2-modified BiVO4 nanosheets

Two-dimensional (2D) BiVO 4 nanosheets (NSs), featuring distinctive chemical properties and dangling-bond-rich surfaces, are promising for developing high-performance gas sensors. However, the previously reported 2D BiVO 4 NSs-based devices suffer from a low responsivity and poor selectivity. In this work, we introduce RuO 2 nanoparticles to boost the gas sensing properties of 2D BiVO 4 NSs-based sensor. Intriguingly, the RuO 2 -decoration changes the selectivity of the corresponding gas sensor from acetone to xylene. Compared to the pristine BiVO 4 sensor, the RuO 2 -BiVO 4 sensor displays a reduced optimal operating temperature of 260℃ and exhibits a response of 19.0–5 ppm xylene, reaching a five-fold enhancement. Simultaneously, the RuO 2 -BiVO 4 sensor also exhibits a rapid response and recovery time of 10 and 25 s respectively, as well as robust long-term stability with less than 5 % variation in response after a storage of 60 days. The improvement in sensing performance can be attributed to the RuO 2 -decoration from three aspects: heterojunction construction, surface state modulation and gas oxidation catalysis on the surface. This work not only provides a high-performance xylene sensing material but also provides insightful comprehension regarding the modification effects of RuO 2 .