Investigation of Rutile, Anatase, and Industrial Titania/Water Solution Interfaces using Potentiometric Titration and Microelectrophoresis

Heterogeneity of Hydroxyl and Deuteroxyl Groups on the Surface of TiO2Polymorphs

“…that the rutile to anatase ratio (in wt%) in commercial titania This result supports the views of Spanos et al (2) who is about 40:60. assumed that the surface of fumed titania consists of patches of rutile and anatase regions with independent acid-base 5.2. Acidity Constants of Surface Hydroxyls behavior, and the proton binding behavior of surface groups inside each region is identical with that of the corresponding At this level of analysis the pK spectra suggest the existence of similar proton binding groups on the surface of pure oxides (2).…”

“…[3]) with the N i , pK i parameters of surface sites for pure rutile one can estimate that about 7.5% of the fumed titania surface and anatase phases and the weighting coefficients, g i , shown is made of rutile-type sites, a figure which is close to that in Table 1. Figure 1 shows that the resulting fit of experimen-(10%) estimated by Spanos et al (2). We regard this as an tal points was not much different from that obtained by independent confirmation of the internal consistency of our direct fit with the N i and pK i values from the original Gauss quantitative analysis of proton affinity distributions.…”

“…model. SURFEQL software was used to determine the surface acidity constants (pK 1 , pK 2 ) and the concentration of…”

The Constant Capacitance Model and Variable Ionic Strength: An Evaluation of Possible Applications and Applicability

“…This will be referred to as the diffuse layer constraint. A similar constraint might be obtained assuming C 1 is known, resulting in C tot Ͻ C 1 [8] which will be referred to as the TLM constraint. Such constraints may be applied to the parameters obtained in this study or to parameters previously published.…”

“…Concerning the application of surface complexation models, there is a somewhat unfortunate development that neglects much of the insight gained in earlier work (2), so that purely diffuse layer models are nowadays applied to high I values, e.g., some cases in (6,7), or the CCM to low I data, e.g., (8,9). The actual failure of the diffuse double layer model (DLM) in many cases has not really become evident, because the data have often been plotted as "raw" data (TOTH vs pH, where the model fits to experimental data look appreciable).…”