Investigating catechol adsorption to the ZnO (1010) surface with and without an oxygen vacancies using the DFT-D2 method

= 2.14 eV) was 1.95 Å, which is close to the bond length between Zn and O of the surface of ZnO. Additionally, a significant change in bond angle was also observed. This clearly shows the chemisorption phenomenon of catechol on the surface of ZnO. Nevertheless, catechol showed weaker chemisorption to the ZnOv surface only in a fully protonated state. In this case, the bond length between the O of catechol and the Zn of ZnO surface was found to be 2.31 Å. In both the surfaces (ZnO and ZnOv), Bader analysis reveals a charge transfer from the surface to the catechol molecule, leading to a reduction in the surface's overall positive charge. Electronic structure changes observed in the valence and conduction bands upon adsorption corroborate these findings. Experimental adsorption kinetics on ZnO nanoparticles further benchmark the DFT results, confirming chemisorption of catechol on the ZnO surface. This combined theoretical and experimental approach advances the understanding of molecule-ZnO surface interactions for the design of functional materials.