Theoretical study of nickel-doped zinc oxide interaction with methylene blue and methyl orange using DFT methods

In this research, the adsorption ofmethylene blue (MB) andmethyl orange (MO) on ZnOand nickeldopedZnO( Ni-ZnO) clusters was investigated through the density functional theory (DFT). The study included the interaction with ionizedMB, neutralMB, ionizedMOand neutralMO. In the case of Ni-dopedZnO, the twoprobabilities of nickelmultiplicities (1 and 3) have been included in the investigation.The interaction betweenwater and ZnOcluster aswell aswater with Ni-ZnOmultiplicity 1 andmultiplicity 3was also studied. The results showed that nickel doping can decrease the bandgap 25.38%which is promising to shift theUVsource to the visible range in the photocatalytic process. For photocatalyst application it will bring themore benefit because it requires the lower energy.Moreover, the nickel doped induce the dye adsorp stronger when the dye attached to dircetly the zinc ion.This guide to design the N-doped ZnOphotocatalystwith no nickel atoms on the surface of the photocatalyst.