Visible Light-activated Room Temperature NO2 Sensing with Au-ZnO Nanorod Array Thin Films

Increasing light absorption is of crucial importance for optimizing light-activated gas detection. However, the relevant research is still rather rare. Herein, high performance NO
₂
gas sensing with plasmonic Au NPs decorated ZnO (AuZnO) nanorod array under visible light illumination at room temperature is demonstrated. It is achieved by the localized surface plasmon resonance (LSPR) and increased surface oxygen vacancies. The influence of light wavelength on the sensing behaviors was systematically investigated. It is found that the Au NPs decoration can largely promote the visible-activated gas sensing behaviors. In addition, the as-prepared sensors demonstrate robustness toward repeatability and selectivity in NO
₂
sensing properties. Moreover, the sensing mechanism based on LSPR was discussed.