Facile synthesis of lattice-defective and recyclable zirconium hydroxide coated nanoscale zero-valent iron for robust arsenite removal
Facile synthesis of lattice-defective and recyclable zirconium hydroxide coated nanoscale zero-valent iron for robust arsenite removal
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DOI：
10.1016/j.seppur.2022.122085
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发表时间：
2022-12
影响因子：
8.6
通讯作者：
Xiaoyao Fan;Lihang Ma;Shu-po Liu;Yujie Xie;Siqi Lu;Z. Tan;Jun‐Pil Ji;Ming‐Lai Fu;Baoling Yuan;Yi-bo Hu
中科院分区：
文献类型：
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作者：
Xiaoyao Fan;Lihang Ma;Shu-po Liu;Yujie Xie;Siqi Lu;Z. Tan;Jun‐Pil Ji;Ming‐Lai Fu;Baoling Yuan;Yi-bo Hu
开发了一种新型核壳结构的氢氧化锆包覆纳米零价铁（NZVI@Zr（OH）4）吸附剂，用于去除水中的砷（As（III））。为优化NZVI@Zr（OH）4的性能，研究了水含量和Zr用量对涂层效率、抗腐蚀稳定性和As（III）去除率的影响。结果表明，包覆率为200wt%（Zr/Fe）的Zr（OH）4壳层可完全包覆NZVI表面，在有氧条件下可保护NZVI芯层免受水溶液腐蚀，并保持其铁磁性。由于NZVI具有较强的铁磁性，当Zr含量高达44.5wt%时，磁饱和值可达32.3emu/g，可同时保证快速磁选回收和较高的As（III）吸附容量。在室温下合成的Zr（OH）4壳层具有弱结晶性和介孔结构。Zr（OH）4壳层表面存在丰富的氧晶格缺陷和未配位的Zr（IV），可用于化学吸附去除As（III）。结果表明，NZVI@Zr（OH）4的容量（380. 0 mg-As·g-1或853. 2 mg-As·g-Zr-1）远高于市售Zr（OH）4和其他磁性Zr基材料，且不受pH值变化、环境阴离子和天然有机物共存的影响。因此，NZVI@Zr（OH）4是一种有前途的材料，可以应用和回收，以去除As（III）在不同的水条件下。
A novel core-shell structured adsorbent, zirconium hydroxide coated nanoscale zerovalent iron (NZVI@Zr(OH)4), was developed for aqueous arsenite (As(III)) removal. The effects of water content and Zr dose for the coating process on the coating efficiency, anti-corrosion stability, and As(III) removal were investigated to optimize the performance of NZVI@Zr(OH)4. The Zr(OH)4shell with a coating ratio of 200 wt% (Zr/Fe) was demonstrated to completely cover the NZVI surface, which can protect the NZVI core from aqueous corrosion in aerobic conditions and maintain its ferromagnetism. Due to the strong ferromagnetism of NZVI, a magnetism saturation value of 32.3 emu/g could be obtained with a high Zr content of 44.5 wt%, which could concurrently guarantee the quick magnetic separation for recycling and the high As(III) adsorption capacity. The Zr(OH)4shell synthesized at room temperature possesses a weak crystalline and mesoporous structure. Abundant oxygen lattice defects with the uncoordinated Zr(IV) on the surface of Zr(OH)4shell could be utilized for the As(III) removal via chemisorption. As a result, the NZVI@Zr(OH)4performed a much higher capacity (380.0 mg-As·g−1or 853.2 mg-As·g-Zr−1) than commercial Zr(OH)4and other magnetic Zr-based materials, which was not affected by the pH variation and the co-existed environmental anions and natural organic matters. Therefore, NZVI@Zr(OH)4is a promising material that can be applied and recycled to remove As(III) under diverse aqueous conditions.