Nanofiber-Structured SnO₂/Co₃O₄ Modified Ta₂O₅ Heterojunction for Room-Temperature Ethanol Sensing

Ternary metal oxide SnO 2 /Co 3 O 4 has attracted much attention for its excellent sensitivity and structural stability. We prepared hollow, rough, and porous SnO 2 /Co 3 O 4 nanofibers using the electrostatic spinning technique in this study. These nanofibers were subsequently compounded with Ta 2 O 5 via the solvothermal method, resulting in the successful synthesis of nanofiber-structured Ta 2 O 5 @SnO 2 /Co 3 O 4 heterojunction materials with outstanding room-temperature ethanol sensing performance. The nanofiber structure of SnO 2 /Co 3 O 4 significantly enhanced the interface for active oxygen adsorption on the Ta 2 O 5 surface, thereby increasing the number of reactive sites for ethanol gas sensitivity. The Ta 2 O 5 @SnO 2 /Co 3 O 4 heterojunction can detect ethanol concentrations as low as 1 ppm at room temperature, with a response value of 6.53 for 100 ppm ethanol. The theoretical detection limit of ethanol for this material can be as low as 522 ppb, as determined by curve fitting. Nanofiber-structured Ta 2 O 5 @SnO 2 /Co 3 O 4 heterojunction materials exhibited comprehensive and excellent room-temperature gas-sensitive properties, suggesting that combining the morphology regulation and heterostructure can provide innovative strategies for room-temperature sensing.