Visible-light photoreduction, adsorption, matrix conversion and membrane separation for ultrasensitive chromium determination in natural water by X-ray fluorescence
Visible-light photoreduction, adsorption, matrix conversion and membrane separation for ultrasensitive chromium determination in natural water by X-ray fluorescence
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DOI：
10.1016/j.snb.2015.12.022
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发表时间：
2016-04
影响因子：
8.4
通讯作者：
Feng-ying Zheng;Xiaofeng Lin;Huiwu Yu;Shunxing Li;Xuguang Huang
中科院分区：
文献类型：
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作者：
Feng-ying Zheng;Xiaofeng Lin;Huiwu Yu;Shunxing Li;Xuguang Huang
将纳米TiO 2固定在纤维素滤纸上，与酸性紫43（TCP-AV）进行表面自组装，并将其用作光催化剂、固相吸附剂、滤膜和化学传感器。由于TCP-AV的紫外-可见光响应范围扩大到750 nm，在可见光照射下，96.0%的Cr（VI）可被光还原为无毒、不动的Cr（III）。TCP-AV对Cr（VI）的光转化作用使天然水中的Cr（VI）和Cr（III）都能富集到TCP-AV上，吸附率达92.7%，这是由于TCP-AV的吸附容量大于4.66mg，且酸性紫43（阴离子染料）与阳离子Cr（III）之间具有较强的电吸引力所致。经基体转换和基体效应消除后，用X射线荧光法直接测定总铬，检出限（3σ，n= 11）从2 mg L− 1提高到0.59 μg L−1。方法的线性范围为2-100 μg L− 1，用于真实的水样中总铬的测定。
Nano-TiO2was immobilized onto cellulose filter paper, surface self-assembled with acid violet 43, denoted as TCP-AV, and used as a photocatalyst, solid phase adsorbent, filter membrane, and chemical sensor. Because the UV–vis wavelength response range of TCP-AV was expanded to 750 nm, 96.0% of Cr(VI) could be photoreduced to nontoxic and immobile Cr(III) under visible-light irradiation. After phototransformation of Cr(VI), both Cr(VI) and Cr(III) in natural water could be enriched onto TCP-AV with an adsorption ratio of 92.7%, which was due to the high adsorption capacity of TCP-AV (more than 4.66 mg) and the strong electric attraction between acid violet 43 (an anionic dye) and cationic Cr(III). After matrix conversion and matrix effects elimination, total chromium was determined directly by X-ray fluorescence, which detection limit (3σ,n= 11) was improved from about 2 mg L−1to 0.59 μg L−1. This proposed method with linear range of 2–100 μg L−1was successfully applied for total chromium determination in real water samples.