LAUSR

Abstract This work reports the preparation of Na-doped ZnO (Na-ZnO) as a promising photocatalyst under sunlight through a very simple precipitation method. The crystal and electronic structures of the prepared Na-ZnO were characterized by experimental techniques and Density Functional Theory (DFT) calculations. Where the DFT calculations revealed that the effect of Na-doping on the ZnO electronic structure is consistent with the experimental observations and the bandgap value found to be decreasing. Under direct sunlight, the as-prepared Na-ZnO decolorized more than 99.5% of the methylene blue dye (MB) after 1.5 h and led to mineralization of 98.3% of it after 3 h. While pure ZnO decolorized only 35% of MB dye at the same conditions. The prepared Na-ZnO has a promising photocatalytic activity at different pH's and high photostability reaching to 7 recycle with the same efficiency. Finally, the primary active species produced during the photocatalytic reaction were determined and the photocatalytic mechanism was elucidated.