Enhancing the sensing performance of WO2.72 toward n-butanol via loading CeO2 nanoparticles

Abstract

Developing n-butanol gas sensors that are simple, stable, sensitive, and humidity-resistant is very important. WO_2.72 nanomaterials have the potential to detect volatile organic compounds (VOCs) due to the abundance of oxygen vacancies and excellent thermal stability. Unfortunately, gas sensors prepared with only WO_2.72 nanomaterials have the disadvantages of low sensitivity, poor humidity resistance ability, and slower response–recovery rate. In this study, CeO₂ nanoparticle-modified WO_2.72 nanoflowers (WO_2.72–x wt% CeO₂) with unique morphologies were synthesized by the solvothermal method and ultrasonic stirring treatment. Characterization results show that the WO_2.72–10 wt% CeO₂ sample was found to possess a larger specific surface area (S_BET) and considerably more oxygen vacancies as compared to the other samples. Then, the n-butanol gas sensors were fabricated using WO_2.72–x wt% CeO₂ samples. As compared with other sensors, it was found that the WO_2.72–10 wt% CeO₂ sensor responded to as high as 103.9 to 50 ppm concentration of n-butanol at 160 °C. Due to the special electronic structure of the rare earth element Ce, the humidity resistance of the WO_2.72–10 wt% CeO₂ sensor was much improved. Additionally, the WO_2.72–10 wt% CeO₂ sensor exhibited a fast response/recovery time (31/78 s) for n-butanol, and the response values remained virtually the same in 5 repetitions and in 15 days stability tests.