Correlation between photoluminescence spectra with gas sensing and photocatalytic activities in hierarchical ZnO nanostructures

Abstract

We synthesized ZnO architectures, including nanorods, porous plates, and flower-like architectures by using different types of zinc salts and surfactants in a hydrothermal process. Photoluminescence spectra demonstrate green emission enhancement owing to both oxygen vacancies and acceptor centers by the passive occupation of sodium ions on the ZnO surfaces. Gas-sensing devices are reported with an enhanced sensing response of nanorods of up to 13 times to NO₂ gas, with respect to ZnO belt-like architectures. In addition, we also measured a high performance in photocatalytic degradation of dye molecules. The correlation between structural defects and gas-sensing properties as well as photocatalytic activity was also discussed.