Nano-zero-valent irons (nZVI) have shown great potential to function as universal and low-cost magnetic adsorbents. Yet, the rapid agglomeration and easy surface corrosion of nZVI in solution greatly hinders their overall applicability. Here, carboxylated cellulose nanocrystals (CCNC), widely available from renewable biomass resources, were prepared and applied for the immobilization of nZVI. In doing so, carboxylated cellulose nanocrystals supporting nano-zero-valent irons (CCNC-nZVI) were obtained via an in-situ growth method. The CCNC-nZVI were characterized and then evaluated for their performances in wastewater treatment. The results obtained show that nZVI nanoparticles could attach to the carboxyl and hydroxyl groups of CCNC, and well disperse on the CCNC surface with a size of ~10 nm. With the CCNC acting as corrosion inhibitors improving the reaction activity of nZVI, CCNC-nZVI exhibited an improved dispersion stability and electron utilization efficacy. The Pb(II) adsorption capacity of CCNC-nZVI reached 509.3 mg·g^–1 (298.15 K, pH = 4.0), significantly higher than that of CCNC. The adsorption was a spontaneous exothermic process and could be perfectly fitted by the pseudo-second-order kinetics model. This study may provide a novel and green method for immobilizing magnetic nanomaterials by using biomassbased resources to develop effective bio-adsorbents for wastewater decontamination.

纳米零价铁（nZVI）已显示出作为通用和低成本磁性吸附剂的巨大潜力。然而，nZVI在溶液中的快速团聚和容易的表面腐蚀大大阻碍了它们的整体适用性。在这里，制备了可从可再生生物质资源广泛获得的羧化纤维素纳米晶体（CCNC），并将其用于nZVI的固定化。这样，通过原位获得了支持纳米零价铁的羧化纤维素纳米晶体（CCNC-nZVI）生长方法。对CCNC-nZVI进行表征，然后评估其在废水处理中的性能。获得的结果表明，nZVI纳米粒子可以附着在CCNC的羧基和羟基上，并以约10 nm的大小很好地分散在CCNC表面上。CCNC作为腐蚀抑制剂可改善nZVI的反应活性，CCNC-nZVI表现出改善的分散稳定性和电子利用效率。CCNC-nZVI的Pb（II）吸附容量达到509.3 mg·g ^–1（298.15 K，pH = 4.0），明显高于CCNC。吸附是自发的放热过程，可以通过拟二级动力学模型完美拟合。这项研究可以通过使用基于生物质的资源开发用于废水净化的有效生物吸附剂，为固定磁性纳米材料提供一种新颖而绿色的方法。