Influences of MgO(001) and TiO₂(101) supports on the structures and properties of au nanoclusters

Due to the unique structures, photoelectric properties, good catalytic activity, and broad potential applications, gold nanoclusters (Au_n) received extensive attention in catalysis, bioengineering, environmental engineering, and so on. In the present work, the structures and properties of Au_n adsorbed on the MgO(001) and TiO₂(101) surfaces were investigated by density functional theory. The results showed that the catalytic properties of Au_n will be enhanced when Au_n is adsorbed on certain supports. Because the difference of the outer electronic structure of metals in supports, the direction of the charge transfer was different, thus inducing the different charge distribution on Au_n. When Au_n was adsorbed on MgO(001) [TiO₂(101)] surface, Au_n will have negative [positive] charges and thus higher catalytic activity in oxidation [reduction] reaction. The variation of surface charges caused by the support makes Au_n possess different catalytic activity in different systems. Moreover, the electronic structure of the support will make an obvious influence on the s and d density of states of Au_n, which should be the intrinsic reason that induces the variations of its structure and properties. These results should be an important theoretical reference for designing Au_n as the photocatalyst applied to the different oxidation and reduction reactions.