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 CeO 2 /WO 2.9 composites with a tunable structure and thickness are originally fabricated by innovating different additional quantities of H 2 WO 4 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 CeO 2 (1.26) at 200 ℃. The unique surface double oxygen defect engineering between CeO 2 and WO 2.9 has a remarkable role in enhanced gas sensing, formation of the CeO 2 -WO 2.9 heterojunction, and effective surface/interface transport mechanism. The electron transfer between WO 2.9 and CeO 2 driven by oxygen defects on the surface of CeO 2 can easily facilitate the interconversion between Ce 3+ and Ce 4+ . This work provides a new insight and the facile fabrication pathway for constructing double oxygen defects-derived CeO 2 -based heterostructures for developing novel n -butanol gas sensors with excellent sensing performance at room temperature.