In-situ deposited ZnO film-based sensor with controlled microstructure and exposed facet for high H2 sensitivity

A facile in-situ solution deposition method is used to fabricate ZnO film-based sensors with controlled microstructures and exposed facets. Three kinds of ZnO film-based sensors with different microstructures and exposed facets were grown on the KMnO4-activated electrode substrates by adjusting the supersaturation level of deposition solution. Among them, the tower-like ZnO film-based sensor with large (0001) exposed area exhibits a high H-2 sensitivity, which is attributed to its abundant oxygen vacancy defects. Moreover, it is found that a proper annealing treatment for the tower-like ZnO film based sensor increases its oxygen vacancies. The H-2 response value of the annealed tower-like ZnO sensor is 2 times higher than that of the non-annealed sensor, and the stability of the sensor is retained after the annealing treatment. (C) 2017 Elsevier B.V. All rights reserved.