Self-templated flower-like WO3-In2O3 hollow microspheres for conductometric acetone sensors

In this article, a novel flower-like WO3-In2O3 hollow heterostructure was successfully constructed by using an in situ etching method. The morphology characteristics revealed that the In2O3 nanoparticles with average sizes of 50 nm were evenly grown at the mesoporous WO3 hollow microsphere composed with self-assembly WO3 nanoplates (WO3 NPs). In order to evaluate advancements of well-designed heterojunction architecture, the gas sensing properties of varying sensors fabricated by pristine WO3, flower-like WO3 hollow sphere, and flower-like WO3-In2O3 hollow heterojunction to acetone gas were systematically investigated. The gas sensing consequences demonstrated that such SH-WO3-In2O3 structure achieved a higher acetone sensing performance with respect to that of pristine WO3 and SH-WO3 sensing materials, which could be ascribed to the promising synergistic effect between admirable flower-hollow structure and n-n type heterojunction configuration. More importantly, this investigation on fabricating well-designed WO3-In2O3 heterostructure may offer new insight and useful strategy to improve the sensing performance for certain metal oxide semiconductor-based gas sensing materials by reasonably utilizing the synergistic effect of structure and component.