Influence of Morphology and Crystallinity on Surface Reactivity of Nanosized Anatase TiO2 Studied by Adsorption Techniques. 2. Solid鈥揕iquid Interface

详细信息    查看全文

• 作者：Mouhamad Ali Ahmad ; Benedicte Prelot ; Fabien Dufour ; Olivier Durupthy ; Angelina Razafitianamaharavo ; Jean Marc Douillard ; Corinne Chaneac ; Fr茅d茅ric Villi茅ras ; Jerzy Zajac
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：March 7, 2013
• 年：2013
• 卷：117
• 期：9
• 页码：4459-4469
• 全文大小：536K
• 年卷期：v.117,no.9(March 7, 2013)
• ISSN：1932-7455

文摘

The aim of this study was to provide new insight into the evaluation of the effect of the crystallinity, size, and morphology of TiO₂-anatase nanoparticles on their acid鈥揵ase properties at the solid鈥搇iquid interface. This was achieved through monitoring the evolution in the surface charge density with the solution acidity and point of zero net proton charge (PZNPC) for a set of anatase nanoparticles with a mean size in the 5鈥?0 nm range and various shapes. Different anatase nanoparticles were obtained by a sol鈥揼el synthesis approach using different precursors, pH conditions, and various inorganic or organic additives. The measured PZNPC values were found to vary more than one pH unit depending on the degree of crystallinity and presence of differently exposed surfaces. To discriminate slight differences in the surface reactivity at the solid鈥搘ater interface, high-resolution titration curves of surface charge for each anatase sample were recorded, and a fine analysis by the titration derivative isotherm summation (TDIS) method and proton affinity distributions (PADs) was performed. They provided accurate data on the strength (pK position) of various local domains of proton adsorption with their relative surface contributions in relation with the particle morphology. The increase in the proportion of sites that are more present on the {101} faces or that of medium acid sites largely present on the {100} faces shifted the point of zero net proton charge to more acidic pH values for particles possessing a majority of such surfaces. In addition to these experiments, the relative acidity of the surface sites on the different surfaces of anatase was evaluated with the multisite complexation model (i.e., MUSIC model) applied to the theoretically optimized surfaces, and a comparison was drawn.