First-principles calculation of OH^-/OH adsorption on gold nanoparticles

The OH^- and OH adsorption structures on Au₅₅ and Au₁₃ nanoparticles surfaces are analyzed using density functional theory. The most stable OH^- adsorption site of Au₅₅ and Au₁₃ nanoparticles is found to be the vertex top site followed by the (111)-(100) edge bridge site. On the contrary, the stability order of OH adsorption is opposite to that of OH^-. The adsorption of OH^- is calculated to be weaker than that of OH, which shows different charge transfer and interactions with gold surface. Coadsorption on nanoparticles is studied to find that multiple OH^- species prefer the most stable sites of single OH^- adsorption. The hydrogen bonding between adsorbed OH^- on gold surface is a key factor in stabilizing the adsorbates on the Au surface.