UV activated metal oxides for chemiresistive-type gas sensors have been recently studied aiming to lower
the working temperature and thus lower the power consumption. In this work, the mesoporous hollow
ZnO microspheres were prepared by template-assisted method and examined for VOCs detection with
UV LED illumination at lower temperatures than 150 ◦C. The as-synthesized ZnO based sensor indicated
an excellent response and selectivity to different concentrations of ethanol (10–1000 ppm) with lowpowered
UV LED (2 mW) at 80 ◦C. The response time is only ∼6 s while the recovery is a little sluggish
(∼94 s). The enhanced sensing performance could be attributed to the mesoporous hollow microstructure
ofthe synthesizedZnO and UVactivateddifferentialphotoctalytic oxidationreactions atthe shallow oxide
surface regions. The repeatability and long term stability of the sensor and the sensor response were also
investigated. A comparison with the conventional thermal-activated gas sensing of the hollow ZnO was
also conducted and the photo-activated gas sensing mechanism was discussed