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对 pH 2～ 1 1 .6和 0 .0 1 mol/L或 0 .1mol/LNaNO3 溶液中 ,δ MnO2 对Au Cl4-,AuCl2 -和Au(S2 O3 ) 2 3 -表现出不同程度的吸附 .在pH 4和两种电解质条件下δ MnO2 吸附AuCl4-和Au(S2 O3 ) 2 3 -后表面金的最大吸附密度分别为 0 .1 8～ 0 .2 1和 0 .2 8μmol/m2 ,金的表面覆盖率约等于或低于 1 % . 3种金络合物的吸附均表现为随pH上升而减少 ,符合阴离子的吸附规律 ;其吸附大小次序为 :Au(S2 O3 ) 2 3 ->AuCl4->AuCl2 -;3种金的本征平衡常数logKint为 1 .1 7～ 2 .71 ,均大大地高于铜和镉的本征吸附常数 ;δ MnO2 优先吸附AuCl4-的水解混合配体络合物 ,并形成内圈表面络合物 .
Δ MnO2 showed different degrees of adsorption on Au Cl4-, AuCl2 - and Au (S2 O3) 2 3 - in pH 2 ~ 11.6 and 0.1 mol / L or 0.1 mol / L NaNO 3 solution. The maximum adsorption densities of Au 4 O 4 and Au (S 2 O 3) 2 3 after adsorption of δ MnO 2 at pH 4 and two electrolytes were 0.18 ~ 0.21 and 0.28 μmol / Of the surface coverage is about equal to or less than 1% .All adsorptions of the three gold complexes showed a decrease with increasing pH, in line with the adsorption law of anions; the adsorption order of the Au (S2O3) 2 3 -> AuCl4-> AuCl2-. The intrinsic equilibrium constants logKint of the three gold species are between 1.7-1.2.71, which are much higher than the intrinsic adsorption constants of Cu and Cd. The δ MnO2 preferentially adsorbs AuCl4- Complex, and form the inner ring surface complex.