Phosphate adsorption onto TiO2 from aqueous solutions:: An in situ internal reflection infrared spectroscopic study
Phosphate adsorption onto TiO2 from aqueous solutions:: An in situ internal reflection infrared spectroscopic study
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DOI：
10.1021/la980894p
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发表时间：
1999-04-13
期刊：
影响因子：
3.9
通讯作者：
McQuillan, AJ
中科院分区：
文献类型：
--
作者：
Connor, PA;McQuillan, AJ
首次通过原位内反射红外光谱研究了水溶液中磷酸根离子在胶体 TiO2 薄膜上的吸附。磷酸盐与 TiO2 牢固结合，与溶液物质相比，吸附物质的红外光谱中 PO 伸缩带结构的巨大变化证明了这一点。 pH = 2.3 时磷酸盐在 TiO2 上的 Langmuir 结合常数为 (3.8 +/- 0.8) x 10(4) dm(3) mol(-1)，这与草酸盐和儿茶酚等二齿配体物种在 TiO2 上的结合常数相似。结合强度在吸附动力学中也很明显，显示出快速吸附和慢得多的解吸，正如预期的那样 强束缚物种。 pH = 8.3 时的动力学数据表明，磷酸盐吸附和解吸依赖于覆盖率。： 使用取代的磷酸盐物质进行的实验已证实磷酸盐与 TiO2 表面的 Ti(IV) 离子呈双齿结合。
The adsorption of phosphate ions from aqueous solution onto;thin films of colloidal TiO2 has been studied for the first time by in situ internal reflection infrared spectroscopy. Phosphate binds strongly to TiO2, as evidenced by the large changes in the PO stretching band structure in the infrared spectrum of the adsorbed species compared with the solution species. The Langmuir binding constant for phosphate onto TiO2 at pH = 2.3 is (3.8 +/- 0.8) x 10(4) dm(3) mol(-1), which is similar to the binding constants onto TiO2 for bidentate ligand species such as oxalate and catechol, The strength of the binding is also apparent in the kinetics of adsorption, showing fast adsorption and much slower desorption, as expected for a strongly bound species. The kinetics data at pH = 8.3 have indicated coverage-dependent phosphate adsorption and desorption.: Experiments with substituted phosphate species have confirmed the bidentate binding of phosphate to Ti(IV) ions at the TiO2 surface.