Department of Environmental Engineering, National Chung Hsing University, Taiwan.
Department of Chemical Engineering, National Chung Hsing University, 250 Kuo- Kuang Road, Taichung, Taiwan.
Carbohydr Polym. 2017 Oct 1;173:412-421. doi: 10.1016/j.carbpol.2017.06.015. Epub 2017 Jun 6.
While ferrocene (Fc) is a promising heterogeneous catalyst for activating persulfate (PS) to degrade organic contaminants, chemical reagent-grade Fc is nanoscale and direct usage of Fc leads to operational and recovery issues. In this study, chitosan (CS) is selected as a support to immobilize Fc as CS is abundant, and environmental benign fishery waste. The amine group of CS also allows the formation of covalent bond between Fc-based reagent (i.e., Fc-CHO) and CS to form Fc-modified CS (Fc-CS). This Fc-CS can be more advantageous than Fc because of its easier recovery by precipitation and filtration. To evaluate Fc-CS for PS activation, degradation of Amaranth (AMR) dye by PS is selected as a model test. The resulting Fc-CS exhibits a higher catalytic activity than pristine Fc possibly because Fc can be evenly dispersed on CS and CS can also exhibit affinity toward AMR. AMR can be also fully decomposed by Fc-CS activated PS. Through the Electron paramagnetic resonance (EPR) spectroscopic analysis, the AMR degradation can be attributed to both sulfate and hydroxyl radicals. Fc-CS had been also proven to activate PS for AMR degradation over multiple times without loss of catalytic activity. These features indicate that Fc-CS can be a promising catalyst and CS appears to be a naturally available and environmentally friendly waste-derived support for immobilizing Fc. The results and findings in this study are essential for CS-supported metal catalysts in environmental applications.
虽然二茂铁（Fc）是一种很有前途的非均相催化剂，可以激活过硫酸盐（PS）来降解有机污染物，但化学试剂级别的 Fc 是纳米级的，直接使用 Fc 会导致操作和回收问题。在这项研究中，壳聚糖（CS）被选为固定 Fc 的载体，因为 CS 丰富，而且是环境友好的渔业废弃物。CS 的氨基还允许 Fc 基试剂（即 Fc-CHO）和 CS 之间形成共价键，形成 Fc 修饰的 CS（Fc-CS）。由于 Fc-CS 更容易通过沉淀和过滤回收，因此它可能比 Fc 更具优势。为了评估 Fc-CS 对 PS 的激活作用，选择 PS 降解苋菜红（AMR）染料作为模型测试。所得的 Fc-CS 表现出比原始 Fc 更高的催化活性，这可能是因为 Fc 可以均匀分散在 CS 上，CS 也对 AMR 表现出亲和力。AMR 也可以被 Fc-CS 激活的 PS 完全分解。通过电子顺磁共振（EPR）光谱分析，AMR 的降解归因于硫酸根自由基和羟基自由基。Fc-CS 已被证明可以在多次使用而不损失催化活性的情况下激活 PS 降解 AMR。这些特征表明 Fc-CS 可以成为一种很有前途的催化剂，CS 似乎是一种天然存在且环保的废物衍生载体，可用于固定 Fc。本研究的结果和发现对于环境应用中的 CS 负载金属催化剂至关重要。
