One-step fabrication of imprinted mesoporous cellulose nanocrystals films for selective separation and recovery of Nd(III)

Previously, we investigated imprinted silica films templated by cellulose nanocrystals for the selective adsorption of rare earth ions from acidic systems, but the cost of organosilane limits the application of silica film adsorbents. Considering the cost and outstanding properties of cellulose, converting this renewable biological resource into an adsorbent material is a vital step towards sustainable development. One-step fabrication of imprinted mesoporous cellulose nanocrystals films (IMCFs) was implemented via ionic imprinting technology and they were applied to efficiently and selectively separate neodymium ions [Nd(III)]. Transmission photographs clearly demonstrated there is a highly ordered mesoporous structure after removal of silicon source. Nitrogen adsorption measurements showed two obtained materials possess high specific surface area, providing a good premise for efficient separation. When employed as absorbents, the maximum adsorption capacity of IMCFs is almost three folds than that of NIMCFs, reaching 18.22 mg g⁻¹. The distribution coefficient of IMCFs for Nd(III) reached 435.46 mL g⁻¹, much higher than other interfering ions. Repeatability tests showed IMCFs retained 81.55% of initial adsorption capacity after five adsorption cycles. In summary, this work presents a new avenue to construct imprinted mesoporous cellulose nanocrystals films for separation of rare earth ions.