Surface area of ferrihydrite consistently related to primary surface charge, ion pair formation, and specific ion adsorption

摘要: Abstract The specific surface area (SSA) of metal oxides is pivotal for scaling phenomena. For ferrihydrite (Fh), the SSA can be assessed by probing with ions that specifically adsorb (e.g. protons or phosphate). In approach, an appropriate material a known chemical behavior used as reference, accounting differences in e.g. sites and structure. As Fh nanomaterial, size-dependency many its properties requires consistent implementation data analysis modeling. present study, proton adsorption was measured NaNO3, NaCl, NaClO4 solutions using potentiometric titration methodology leads to internally primary set (H/Fe). interpretation, we employed size-dependent molar mass, mass density, composition (FeO1.4(OH)0.2·nH2O), well curvature since latter increases value Stern layer capacitance. Using well-crystallized goethite state-of-the-art multisite complexation modeling discloses underlying Fh. Similar goethite, significant variation electrolyte affinity constants (logK) found This largely explains pHPZC reported literature when KNO3 NaCl rather than NaNO3 solution. Our collection done materials aging history. same samples were also probed phosphate collected (PO4/Fe) interpreted CD model. yields values are those protons. ion rapid sensitive, it recommended tool determine materials. enables development thermodynamic database application natural systems.