Light-activated room-temperature gas sensor based on surface and structural engineering of 3D ordered nanostructure

Abstract

A semiconductor metal oxide (SMOs)-based gas sensor has been investigated due to their high sensitivity to harmful gases in atmosphere. Especially, the developments of nanotechnology enable the fabrication of SMOs into nanostructure with higher gas sensing performance. However, there are still limitation to utilize SMOs -based gas sensor such as low gas selectivity due to high gas sensitivity to various gases and high operating temperature requirements. In order to address such issues of SMOs, various chemical and structural approaches have been suggested and applied. In this thesis, I report the fabrication strategy for room temperature gas sensor using 3D hierarchical nanostructure and the base research on surface and structure engineering of SMOs for improving gas sensing ability of SMOs. The comprehensive study for better understanding the role of catalyst on metal oxide is reported with enhanced gas sensing performance with noble metal nanoparticles and graphene quantum dots. In the structural respects, the light-absorption enhancement for photo-activated room temperature gas sensing was achieved by structural engineering of periodic 3D nanostructure. With the integration to micro-LED device, realizing fabrication of low power consumption light-activated gas sensor. As a conclusive work, 3D ZnO/ZIF-8 hierarchical nanostructure is fabricated in ordered periodic nanostructure. The gas filter behavior of metal-organic framework at the surface of metal oxide was demonstrated for high gas selectivity and sensitivity. The high-performance photo-activated room temperature gas sensor were fabricated as optimized 3D nanostructure with catalytic metal-organic framework.