Adsorption of water on NaNO3(001) surface from first-principles calculations

作者:Luo Jin Hua; Hu Ai Min; Wang Xiao Lin; Zhang Yun Hong*; Li Ze Sheng
来源:Journal of Colloid and Interface Science, 2013, 393: 340-346.
DOI:10.1016/j.jcis.2012.11.004

摘要

Density functional theory (DFT) calculations were applied to investigate the adsorption of water monomer, water clusters on NaNO3(001) surface. Single water molecule is more likely to locate on the bridge site with its H atom attracted by the O atom of nitrate ion and its O atom adjacent to Na+. Mulliken population analysis shows that fewer electrons transfer from the Na atom of substrate to water molecule. A systematic study of water clusters adsorption at high coverages ranging from 0.5 monolayer (ML), 0.75 ML, 1 ML, 1.25 ML, and 1.5 ML on NaNO3(001) surface was also investigated, and the results indicate that for 1 ML water adsorption on NaNO3(001) surface, a water chain is formed among four water molecules through hydrogen bonds. Interestingly, the water molecules are linked through hydrogen bonds to form a 14-membered macrocyclic water ring for 1.5ML adsorption on NaNO3(001) surface. Our estimated O-H symmetric stretching frequency (nu(O-H)) will have blueshift with decrease of water coverage, which is consistent with the tendency given by experiments.