Exploring ZnO/Montmorillonite photocatalysts for the removal of hazardous RhB Dye: A combined study using molecular dynamics simulations and experiments

Photocatalytic degradation of pollutants by nanocomposites is one of the most interesting methods used around the world. However, it is difficult for photocatalysts to provide excellent absorption of the photons of light, and at the same time recombination of the photogenerated electron-hole and agglomeration of the nanoparticles is applicable. Therefore, a catalyst is fulfilling these criteria by supporting on clay particles, such as ZnO/Montmorillonite (ZnO/Mt) nanocomposite which is synthesized in the present work by simple co-precipitation approach. Assessing the efficiency of the Rhodamine B (RhB) photocatalytic breakdown process is showed that the ZnO/Mt photocatalyst exhibited better photocatalytic performance in comparison to pure ZnO. The enhanced photocatalytic performance of the ZnO/Mt photocatalyst is attributed to the beneficial interaction between montmorillonite and ZnO nanoparticles. Further, theoretical analysis is conducted to examine the RhB dye adsorption on the ZnO/Mt photocatalyst. At the first, all used compounds are optimized by DFT-D calculations; the HOMO/LUMO and the total energy are also obtained. Then, the molecular dynamic (MD) simulation is used for ZnO adsorption on Montmorillonite (Mt) by using Monte Carlo adsorption locator module. After forming nanocomposite, the adsorption energy of RhB (Ead) on ZnO/Mt is applied, indicating that the adsorption process is a result of negative interaction energy. Additionally, the energy required for RhB to adsorb on ZnO/Mt is found to be greater than the energy required for RhB to adsorb on Mt alone.