Zirconia (ZrO2) Embedded in Carbon Nanowires via Electrospinning for Efficient Arsenic Removal from Water Combined with DFT Studies

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• 作者：Jinming Luo ; Xubiao Luo ; Chengzhi Hu ; John C. Crittenden ; Jiuhui Qu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：July 27, 2016
• 年：2016
• 卷：8
• 期：29
• 页码：18912-18921
• 全文大小：602K
• 年卷期：0
• ISSN：1944-8252

文摘

To use zirconia (ZrO₂) as an efficient environmental adsorbent, it can be impregnated on a support to improve its physical properties and lower the overall cost. In this study, ZrO₂ embedded in carbon nanowires (ZCNs) is fabricated via an electrospinning method to remove arsenic (As) from water. The maximum adsorption capacity values of As(III) and As(V) on the ZCNs are 28.61 and 106.57 mg/g, respectively, at 40 °C. These capacities are considerably higher than those of pure ZrO₂ (2.56 and 3.65 mg/g for As(III) and As(V), respectively) created using the same procedure as for the ZCNs. Meanwhile, the adsorption behaviors of As(III) and As(V) on the ZCNs are endothermic and pH dependent and follow the Freundlich isotherm model and pseudo-first-order kinetic model. Both As(III) and As(V) are chemisorbed onto the ZCNs, which is confirmed by a partial density of state (PDOS) analysis and Dubinin–Radushkevich (D-R) model calculations. Furthermore, the ZCNs also possess the capability to enhance or catalyze the oxidation process of As(III) to As(V) using dissolved oxygen. This result is confirmed by a batch experiment, XPS analysis and Mulliken net charge analysis. Density functional theory (DFT) calculations indicate the different configurations of As(III) and As(V) complexes on the tetragonal ZrO₂ (t-ZrO₂)(111) and monoclinic ZrO₂ (m-ZrO₂)(111) planes, respectively. The adsorption energy (E_ad) of As(V) is higher than that of As(III) on both the t-ZrO₂(111) and m-ZrO₂ (111) planes (3.38 and 1.90 eV, respectively, for As(V) and 0.37 and 0.12 eV, respectively, for As(III)).