Temperature-Dependent Interfacial Performances of TiO₂-H₂O with Plasmonic Metal Clusters

Modification of TiO2 with a plasmonic metal is an effective way to improve the efficiency of hydrogen production by photoelectrochemical water splitting. In this work, we focused on the influence of Ag nanoparticles and the temperature rise induced by the thermoplasmonic effect on the interfacial performances of TiO2-H2O. First, we calculated the interfacial properties such as the water density, Helmholtz layer width, surface electrostatic potential, and water diffusion coefficient by molecular dynamics at 298–368 K based on the model of TiO2 loaded Ag20 clusters combined with the simulation of the density functional theory on the analysis of the adsorption energy, desorption time of water molecule, etc. The results show that the Helmholtz layer width and the surface electrostatic potential decrease upon loading Ag nanoparticles on the TiO2 surface, but the adsorption energy of water molecules increases and the delamination of water molecules weakens due to the interaction between Ag nanoparticles and water molecules on the TiO2 surface. With the increase of temperature, the adsorbed water molecules on the surface of Ag/TiO2 decrease, and there is little effect on the delamination structure of water molecules. The enhanced surface electrostatic potential and diffusion coefficient with temperature rise are favorable for the interfacial reaction, while the desorption time of water molecules decreases rapidly with temperature rise, resulting in the desirable temperature of about 318 K for the interface reaction.