Vibrational study of Li-doped ZnO sprayed thin films along with sensors under ethanol vapor and photocatalytic applications

This work covers additional physical investigations on lithium-doped ZnO sprayed thin films regarding their both ethanol vapor sensing property as well as photocatalytic applications, in comparison with what have already been published on these films in terms of structural and nanomechanical studies as reported recently by the same authors in Journal of Materials Science: Materials in Electronics 30 (2), 1767–1785 (2019). Herein, vibrational study has been made on Li-doped ZnO sprayed thin films showing that Li doping does not affect vibration modes of ZnO undoped film. Moreover, the photocatalytic performance of Li-doped films has been tested against both Rhodamine B (RhB) and Methylene blue (MB) dyes under UV irradiation. It is found that film prepared using 2% Li content stands for an obvious efficiency power of UV radiation to degrade the dyes. Also, the impact of ( OH . ) and ( O 2 . - ) radicals on the photocatalytic mechanism was also investigated as a function of the surface roughness effect provided by means of the atomic force microscopy (AFM). A specific emphasis is put on the sensitivity of the ethanol detection by ZnO: Li sensors as a function of working temperature, polarization and gas concentration.