Naslov
Electrochemical insights into spatial complexity of hematite - dicarboxylate interactions at the interface

Autori
Kędra, Karolina ; Begović, Tajana ; Łazarczyk, Marzena ; Namjesnik, Danijel ; Zarzycki, Piotr

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
27th Croatian Meeting of Chemists and Chemical Engineers and 5th Symposium Vladimir Prelog : Book of Abstracts / Marković, Dean ; Meštrović, Ernest ; Namjesnik, Danijel ; Tomašić, Vesna - Zagreb : Hrvatsko kemijsko društvo, 2021, 285-285

Skup
27. hrvatski skup kemičara i kemijskih inženjera (27HSKIKI)

Mjesto i datum
Veli Lošinj, Hrvatska, 05.10.2021. - 08.10.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Adsorption of soil organic matter (SOM) ; minerals surface ; hematite ; hematite/electrolyte electrical double layer ; diarboxylate ions ; surface charge density ; surface potential ; electokinetic potential

Sažetak
Adsorption of soil organic matter (SOM) at minerals surface is very important phenomena in the environment resulting in organic matter (OM) protection against degradation. Hematite is known to play important role in carbon accrual in the on Earth, however its role may be reversed in some conditions. To shed light on the interactions of organic matter with iron oxides, we investigated the properties of the hematite/electrolyte electrical double layer in the presence of dicarboxylate ions. Here by combining of three electrochemical descriptors (surface charge density (σ0), surface potential (Ψ0) and electokinetic potential (ζ) we gain new insight into pH-dependent malonates interactions with hematite surface in the solution. Malonates adsorb to hematite surface in a wide pH range between 3 and point of the zero charge (pHpzc = 8.7). However, the mode of coordination depends on a pH value. We distinguished two different malonates complexation types: inner-spherical complexes at pH below 4 and outer-spherical above pH 5. The surface charge and potential are sensitive to malonate concentration in acidic conditions. As the pH increases, we only observe the zeta potential sensitive to malonate ions as a response to their accumulation in the shear plane. The transition from the inner to the outer sphere geometries is smooth, suggesting that both types of complexes geometries exist simultaneously with a ratio depending on the pH.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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