A comparative study on the removal of cylindrospermopsin and microcystins from water with NF-TiO2-P25 composite films with visible and UV–vis light photocatalytic activity
A comparative study on the removal of cylindrospermopsin and microcystins from water with NF-TiO2-P25 composite films with visible and UV–vis light photocatalytic activity
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DOI：
10.1016/j.apcatb.2012.03.010
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发表时间：
2012-06
影响因子：
22.1
通讯作者：
M. Pelaez;F. Falaras;A. Kontos;A. A. Cruz-A.;K. O’Shea;P. Dunlop;J. Byrne;D. Dionysiou
中科院分区：
文献类型：
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作者：
M. Pelaez;F. Falaras;A. Kontos;A. A. Cruz-A.;K. O’Shea;P. Dunlop;J. Byrne;D. Dionysiou
在这项研究中，为了开发与最先进的材料相比具有更高光效率和可见光响应的光催化剂材料，研究了赢创Aeroxy®P25-TiO2(P25)纳米粒子在改进的溶胶-凝胶工艺中的作用，以产生复合氮和氟掺杂的TiO2-P25 (NF-TiO2-P25)薄膜。在溶胶中添加 P25 纳米粒子会导致更高的 BET 表面积、孔体积、孔隙率和总 TiO2 质量，以及热处理后薄膜的更大厚度和粗糙度。显微镜技术证实了形成的 NF-TiO2 溶胶凝胶和具有不同平均尺寸的 P25 纳米颗粒的部分烧结。在显微拉曼光谱中证实了仅来自 NF-TiO2 的锐钛矿和来自 P25 的锐钛矿-金红石混合物的明确区域的存在。在可见光和紫外可见光下，使用 NF-TiO2 和 NF-TiO2-P25 薄膜评估了四种微囊藻毒素（微囊藻毒素-LR、-RR、-LA 和 -YR）和圆柱藻蛋白酶的光催化降解效果。在酸性条件下（pH 3.0），微囊藻毒素的一般反应性为：MC-LA>MC-LR≥MC-YR>MC-RR，其中 NF-TiO2-P25 薄膜实现了最高的初始降解率（当可见光照射时，溶胶中的 P25 为 5gL−1，当紫外-可见光照射时，溶胶中的 P25 为 15gL−1）。所有膜在 pH 3.0 时圆柱精蛋白的吸附都可以忽略不计。尽管如此，在紫外可见光下发现了显着的光催化去除作用，最大 P25 负载薄膜表明降解是由光生活性氧的参与介导的，而不是由正空穴的捕获反应介导的。
In this investigation, in order to develop photocatalyst materials with improved photo-efficiency and visible light response compared to the state of the art materials, the role of Evonik Aeroxide®P25-TiO2(P25) nanoparticles incorporated in a modified sol–gel process to yield composite nitrogen and fluorine doped TiO2-P25 (NF-TiO2-P25) films was investigated. The addition of P25 nanoparticles in the sol leads to higher BET surface area, pore volume, porosity and total TiO2mass, as well as larger thickness and roughness of the films after heat treatment. Microscopy techniques confirmed partial sintering of NF-TiO2sol–gel formed and P25 nanoparticles having different average size. The existence of well defined regions of only anatase from NF-TiO2and anatase–rutile mix from P25 was verified in the micro-Raman spectra. The photocatalytic degradation of four microcystins (microcystin-LR, -RR, -LA and -YR) and cylindrospermopsin was evaluated with NF-TiO2and NF-TiO2-P25 films under visible and UV–vis light. The general reactivity for the microcystins under acidic conditions (pH 3.0) was: MC-LA>MC-LR≥MC-YR>MC-RR where the highest initial degradation rate was achieved with the NF-TiO2-P25 films (5gL−1of P25 in sol when irradiated with visible light and 15gL−1of P25 in sol when irradiated with UV–vis light). Cylindrospermopsin showed negligible adsorption at pH 3.0 for all films. Nevertheless, significant photocatalytic removal was found under UV–vis light with maximum P25 loaded films indicating that the degradation was mediated by the involvement of photogenerated reactive oxygen species and not by the trapping reaction of the positive hole.