Piasecki Wojciech, Lament Karolina
Department of Physical Education and Health, Józef Piłsudski University of Physical Education in Warsaw, Akademicka 2, 21-500 Biała Podlaska, Poland.
Molecules. 2024 Nov 26;29(23):5595. doi: 10.3390/molecules29235595.
We have shown that the adsorption of Cu ions on various metal oxides, depending on the pH of the solution, can be described assuming the formation of only two surface complexes with surface hydroxyl groups SOH: SOCu(OH) and SOCu. Using an ion-selective electrode for Cu, we determined the adsorption edges, i.e., the dependence of the amount of adsorbed metal expressed as a percentage depending on the solution pH for three oxides: TiO, AlO, and SiO. The measurements were carried out with high surface coverage where the ratio of the adsorption sites/copper ions in the system were from 2 to 3, depending on the oxide. Simultaneously, with the adsorption edge, the hydrogen surface charge density and the electrokinetic potential of the oxide particles were measured as a function of pH. These three types of experimental data were fitted all together using the surface complexation model (2-pK TLM). In modeling, it was not necessary to consider the precipitation of Cu(OH) on the oxide surface to obtain good agreement with the data. Additionally, it was shown that the presence of charged surface species SOCu (about 10% of total adsorbed copper) was crucial to fit the data for zeta potential.
我们已经表明，根据溶液的pH值，铜离子在各种金属氧化物上的吸附情况可以通过假设仅形成两种与表面羟基SOH的表面络合物来描述：SO Cu(OH)和SO Cu。使用铜离子选择性电极，我们确定了三种氧化物（TiO、AlO和SiO）的吸附边缘，即吸附的金属量以百分比表示对溶液pH值的依赖性。测量是在高表面覆盖率下进行的，系统中吸附位点/铜离子的比例根据氧化物的不同在2到3之间。同时，随着吸附边缘的变化，测量了氧化物颗粒的氢表面电荷密度和电动电势随pH值的变化。使用表面络合模型（2-pK TLM）将这三种类型的实验数据一起进行拟合。在建模过程中，无需考虑Cu(OH)在氧化物表面的沉淀即可与数据取得良好的一致性。此外，结果表明，带电表面物种SO Cu（约占总吸附铜的10%）的存在对于拟合zeta电位数据至关重要。
