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Evaluation of Intrinsic Ionization and Complexation Constants of TiO 2 and Mg‐Fe Hydrotalcite‐like Compounds
Author(s) -
Hou WanGuo,
Ren Carolyn
Publication year - 2006
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200690249
Subject(s) - chemistry , extrapolation , hydrotalcite , int , charge (physics) , analytical chemistry (journal) , surface charge , effective nuclear charge , organic chemistry , ion , mathematical analysis , physics , mathematics , quantum mechanics , catalysis , computer science , operating system
The intrinsic surface reaction constants, p K int a1 , p K int a2 , p * K int C and p * K int A , were evaluated by a modified double extrapolation (MDE) for TiO 2 without structural charge and Mg‐Fe hydrotalcite‐like compounds (HTlc) with structural charge, respectively. The results of intrinsic surface reaction constants for TiO 2 were compared with those obtained by class double extrapolation (CDE) in literature. Furthermore, the values of intrinsic surface reaction constants obtained by MDE were used to simulate the charging behaviors of the materials. The following conclusions were obtained. For TiO 2 without structural charge, the p K int a1 and p K int a2 evaluated by MDE are equal to those by CDE, however the p * K int C and p * K int A evaluated by MDE are much different from those by CDE. In principle, the results of the p * K int C and p * K int A evaluated by MDE are more accurate than those by CDE. The values of intrinsic surface reaction constants obtained by MDE can excellently simulate the charging curves for TiO 2 with the triple layer model (TLM). For HTlc with positive structural charge, the results of * K int C =0 and * K int A →∞ were obtained by MDE, which means the inert electrolyte chemical binding does not exist; the point of zero net charge (PZNC) of c ‐independence also exist as the same as solid without structural charge, and the pH PZNC obtained by the acid‐base titration can excellently be simulated and the surface charging tendency can be simulated to a great extent using the p K int a1 and p K int a2 evaluated by MDE and the diffuse layer model (DLM).