LAUSR

Abstract Designing and constructing heterostrucutres is the trend of enhancing sensing performance of metal oxide semiconductor based gas sensors. A new kind of porous Co 3 O 4 /Ta 2 O 5 heterostructure hollow nanospheres was successfully synthesized by the assistance of carbon colloidal nanospheres and following annealing. The Ta 2 O 5 nanostructures with ultrathin hollow spherical shell (∼5 nm) were attached with numerous Co 3 O 4 nanoparticles, forming heterojunction in the contact surface. The Ta 2 O 5 hollow spheres act as the supporting model, hindering the aggregation of Co 3 O 4 nanoparticles and possessing more specific surface area. For room temperature (25 °C) gas sensing application, the Co 3 O 4 /Ta 2 O 5 hollow nanospheres exhibited outstanding ethanol detecting properties. The gas response toward 10, 20, 50, and 100 ppm of ethanol achieved 20%, 50%, 90% and 180%, respectively. The Co 3 O 4 /Ta 2 O 5 hollow nanospheres also exhibited outstanding selectively and reliable stability, which can be attributed to the formation of the heterojunction in the contact surface of Co 3 O 4 and Ta 2 O 5 , leading to the extension of electron depletion layer.