College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China.
Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Zhangzhou 363000, China; College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China.
Talanta. 2018 Apr 1;180:352-357. doi: 10.1016/j.talanta.2017.12.069. Epub 2017 Dec 24.
Using ammonium molybdate and thiourea as precursors, nitrogen-doped MoO was produced by a one-step carbonization and then fixed into the cellulose filter paper (NMCP) with acrylic resin as a fixative. NMCP was designed as a multifunctional nanocomposite, i.e., solid phase adsorbent for Fe(III) preconcentration, photocatalyst for iron species transformation and color interference removal, and colorimetric sensor for Fe(III) determination. After photocatalysis, the complex of Fe-humic substances could be transformed into Fe(III) ions, the interference of colored organic matter (e.g., aqueous humic substance) was removed, Fe(III) was enriched selectively onto NMCP with the coexistence of interference metal ions (e.g. Co(II) and Cd(II)) and then transformed into Fe(II) by hydroxylamine and photoreduction and for colorimetric analysis. The obstacle of o-phenanthroline colorimetric method was overcome. The photodegradation activity of MoO was improved 2.02 times by nitrogen doping with the optimal mass ratio, which was also 5.11 times of P25-TiO. The concentration of Fe(III) on NMCP was quantified by the gray-scale using smart phones and image processing software, without complicated equipment. Based on multifunctional NMCP, a fully integrated visual analysis system was proposed and suitable for the field detection of Fe(III) in natural water. The log-linear calibration curve for Fe(III) was in the range of 0.05-5mg/L with a determination coefficient (R) of 0.976 and detection limit of 15μg/L.
以钼酸铵和硫脲为前驱体，通过一步碳化法制备氮掺杂 MoO，并将其固定在以丙烯酸树脂为固定剂的纤维素滤纸（NMCP）上。NMCP 被设计为一种多功能纳米复合材料，即用于 Fe(III)预浓缩的固相吸附剂、用于铁物种转化和去除颜色干扰的光催化剂以及用于 Fe(III)测定的比色传感器。光催化后，Fe-腐殖质复合物可转化为 Fe(III)离子，有色有机物（如水中腐殖质）的干扰被去除，共存的干扰金属离子（如 Co(II)和 Cd(II)）可选择性地将 Fe(III)富集到 NMCP 上，然后通过羟胺和光还原转化为 Fe(II)并进行比色分析。克服了邻菲啰啉比色法的障碍。氮掺杂使 MoO 的光降解活性提高了 2.02 倍，最佳质量比为 5.11 倍，优于 P25-TiO。通过智能手机和图像处理软件对 NMCP 上的 Fe(III)浓度进行灰度量化，无需复杂的设备。基于多功能 NMCP，提出了一种完全集成的可视化分析系统，适用于天然水中 Fe(III)的现场检测。Fe(III)的对数线性校准曲线在 0.05-5mg/L 范围内，相关系数（R）为 0.976，检测限为 15μg/L。
