Point of Zero Charge, Iron Hydroxide-Solution Interface, Adsorption of Ions, Thermodynamics of Adsorption.
Abstract
The point of zero charge (PZC) of iron hydroxide has been determined between 30 and 60°C by measuring the distribution of the potential determining ions (H+, OH-) at the hydroxide-solution interfaces for six different electrolytes (LiCl, NaCl, KCl, LiNO3, NaNO3 and KNO3). For all these electrolytes a decrease in PZC has been observed. The cationic effect on the PZC of iron hydroxide (am) has been observed similar to lyotropic series i.e. Li+ > Na+ > K+. The investigated anionic effect for iron hydroxide is greater for nitrates than those of chlorides. Furthermore ΔH*, ΔS* and ΔG0* have been calculated by using Berube and DeBruyn equation.