Single-Crystal Mesoporous ZnO Thin Films Composed of Nanowalls

This paper presents a controlled, large scale fabrication of mesoporous ZnO thin films. The entire ZnO mesoporous film is one piece of a single crystal, while high porosity made of nanowalls is present. The growth mechanism was proposed in comparison with the growth of ZnO nanowires. The ZnO mesoporous film was successfully applied as a gas sensor. The fabrication and growth analysis of the mesoporous ZnO thin film give general guidance for the controlled growth of nanostructures. It also provides a unique structure with a superhigh surface-to-volume ratio for surface-related applications.