Quantitative XANES Studies on Metastable Equilibrium Adsorption of Arsenate on TiO2 Surfaces
文献类型：期刊论文
| 作者 | He, Guangzhi ; Pan, Gang ; Zhang, Meiyi ; Wu, Ziyu |
| 刊名 | JOURNAL OF PHYSICAL CHEMISTRY C
 |
| 出版日期 | 2009-10-01 |
| 卷号 | 113期号:39页码:17076-17081 |
| 中文摘要 | Quantitative information on the electronic and geometric structures of adsorption complexes of arsenate on TiO2 surfaces was obtained on the basis of XANES analysis combined with DFT calculation. The density of states (DOS) showed that the As(V) K-absorption edge corresponded to the dipole transition from the As Is electron into the As(4p)-O(2p) antibonding molecular orbital, suggesting that the bonding between arsenate and TiO2 was primarily due to the interaction of As 4p and O 2p orbitals. Previous EXAFS studies indicated that both bidentate binuclear (BB) and monodentate mononuclear (MM) surface complexes coexisted in the As(V)-TiO2 adsorption system. DFT calculation showed that the XANES transition energy of the BB complex was significantly higher than that of the MM complex. Thus, quantitative information on adsorption microstructures call be obtained by measuring the blue-shift of the XANES absorption edge. XANES results of adsorption samples at different kinetic stages indicated that there was a structural evolution from the MM complex to the BB complex as the reaction processed to adsorption equilibrium. Therefore, the final proportion between BB and MM complexes in the real equilibrium state was fundamentally affected by surface coverage and kinetic pathways. This fact implied that the real equilibrium constant, when defined by macroscopic parameters of concentration and adsorption density (mol/m(2)), are generally inconstant in nature and hence cannot describe the real equilibrium properties of adsorption, because different microscopic metastable equilibrium adsorption structures that construct the real adsorption equilibrium cannot be counted for both mass and energy by the macroscopic parameter of surface concentrations (mol/m(2)). |
| WOS记录号 | WOS:000269999700037 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/21727]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | He, Guangzhi,Pan, Gang,Zhang, Meiyi,et al. Quantitative XANES Studies on Metastable Equilibrium Adsorption of Arsenate on TiO2 Surfaces[J]. JOURNAL OF PHYSICAL CHEMISTRY C,2009,113(39):17076-17081. |
| APA | He, Guangzhi,Pan, Gang,Zhang, Meiyi,&Wu, Ziyu.(2009).Quantitative XANES Studies on Metastable Equilibrium Adsorption of Arsenate on TiO2 Surfaces.JOURNAL OF PHYSICAL CHEMISTRY C,113(39),17076-17081. |
| MLA | He, Guangzhi,et al."Quantitative XANES Studies on Metastable Equilibrium Adsorption of Arsenate on TiO2 Surfaces".JOURNAL OF PHYSICAL CHEMISTRY C 113.39(2009):17076-17081. |
入库方式： OAI收割
来源：生态环境研究中心
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