Insights into the adsorption mechanism of water at different coverage rates on talc (Mg3Si4O10(OH)2) (0 0 1) basal surface: A first-principles study

Abstract

Study on the interaction between water and mineral surface is significant for the understanding of the subsequent interfacial reactions during the flotation. In this work, the adsorption of water at different coverage rates on talc (001) basal surface was creatively researched by first-principles calculations. We found the single water adsorption on talc (001) basal surface was majorly through the H-bond between surface Os and water Hw and H-bond between surface Hs and water Ow with the adsorption energy ranges from −24.26 kJ/mol to −3.8 kJ/mol, and the bonding mechanism of H-bond was attributed to the orbital hybridization of H atom and O atom. Furthermore, we found more H-bonds were formed on talc surface with the increasing water coverage rates, and the average adsorption energy of water was gradually decreased. Thus, the adsorption of water on talc (001) basal surface was enhanced with the increasing water coverage rates, and the talc surface became more stable after water adsorption. Moreover, charge transfers from water to the talc surfaces occurred, and the work function of talc surfaces gradually decreased when the coverage rates of water were low while increased when the coverage rates of water were higher.