کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
592390 1453904 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Polymerization of silicate on TiO2 and its influence on arsenate adsorption: An ATR-FTIR study
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Polymerization of silicate on TiO2 and its influence on arsenate adsorption: An ATR-FTIR study
چکیده انگلیسی


• Molecular-level interaction of Si and As(V) on TiO2 was studied with in situ ATR-FTIR.
• The As(V) surface structure remained unchanged in the presence of Si.
• The As(V) adsorption released the adsorbed Si monomers and dimers.
• Si oligomers and polymers greatly inhibited As(V) adsorption.

The exposure risks of toxic arsenic in the environment are dependent on the adsorption and desorption processes at solid/aqueous interfaces, which could be greatly influenced by co-existing oxyanions such as silicate. In the present work, the adsorption of arsenate [As(V)], silicate (Si), and the influence of silicate on As(V) adsorption are investigated at the molecular level by in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Silicate monomer, dimer, oligomer, and polymer were detected on the TiO2 surface after 3 h, and silicate oligomer was the predominant surface species under the experimental conditions. The presence of silicate with different silicate and As(V) adsorption sequences did not interfere with As(V) surface species on TiO2, but only affected the As(V) adsorption capacity. For silicate, the adsorption of As(V) could greatly inhibit the formation of Si monomer and dimer on TiO2, but the silicate oligomer and polymer were not influenced by As(V) adsorption. The silicate oligomeric and polymeric surface species will gradually occupy the TiO2 surface sites to inhibit As adsorption and TiO2 regeneration. Our findings provide spectroscopic evidence and clearly elucidate the molecular-level interactions of silicate and As(V) on TiO2, which will further our understanding of the removal of As in groundwater.

Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Colloids and Surfaces A: Physicochemical and Engineering Aspects - Volume 469, 20 March 2015, Pages 180–186
نویسندگان
, , ,