Electronic structure of ZnO photo-catalyst; A DFT study

To calculate electronic properties of ZnO in wurtzite phase, using the r-PBE GGA method, the ABINIT code has been used. Our analysis shows that ZnO has a hexagonal structure with cell parameters of a = 3.27 and c = 5.23 angstrom which are in line with the previous DFT-GGA results. Also, corresponding to the experimental results, the numerical calculated value of 2.4 eV for the band gap showed more accurate results than the previous GGA and LDA accounting. The analysis of the calculated band structure shows that ZnO in the wurtzite phase has a direct band gap. While it results in much absorption coefficient but decreases the photo-induced electron-hole life time and demotes the photocatalytic activity consequently.