Surface double oxygen defect engineering in button-shaped porous CeO2/WO2.9 heterostructures for excellent n-butanol detection at room temperature

In the present work, a series of CeO2/WO2.9 composites with a tunable structure and thickness are originally fabricated by innovating different additional quantities of H2WO4 during the hydrothermal process. Optimal Ce/W-0.25 sensors have a higher response value of 23.68 to 100 ppm n-butanol at room temperature than that of pure CeO2 (1.26) at 200 ℃. The unique surface double oxygen defect engineering between CeO2 and WO2.9 has a remarkable role in enhanced gas sensing, formation of the CeO2-WO2.9 heterojunction, and effective surface/interface transport mechanism. The electron transfer between WO2.9 and CeO2 driven by oxygen defects on the surface of CeO2 can easily facilitate the interconversion between Ce3+ and Ce4+. This work provides a new insight and the facile fabrication pathway for constructing double oxygen defects-derived CeO2-based heterostructures for developing novel n-butanol gas sensors with excellent sensing performance at room temperature.