Construction of chitosan/wurtzite multiple sites on mesoporous halloysite and selective removal of Al(III) from rare earth ions solution: Microcalorimetry investigation

Herein, organic/inorganic multiple adsorption sites were constructed on halloysite to intensify the selective adsorption performance of the adsorbent for Al(III) in rare earth solutions. The adsorption heat behavior and thermodynamics of the composite for different ion systems were investigated using microcalorimetry. The results showed that chitosan formed a mesoporous membrane on the acid-treated calcined halloysite (Hal H) substrate through a strong electron interaction between the nitrogen atom of the amino group and the oxygen atom of Si O structure on Hal H. Wurtzite was loaded onto the chitosan mesoporous membrane as nanoparticles and partially oxidized to the ZnO phase of wurtzite. [email protected] demonstrated excellent adsorption capacity ( q max (Al 3+ ) was 102.04 mg/g), selectivity performance (Ks was 1583.06), adaptation to varying ion concentrations and structural stability in the mixed solution. Solution pH, ion concentration and temperature significantly affected the adsorption heat behavior and thermodynamics of the composite in different ion systems. The efficient selective adsorption of Al(III) by [email protected] was achieved through chelation with the amide and amino groups of chitosan and chemical interaction with sulfur groups of wurtzite. This work exemplifies a promising strategy for designing novel mineral materials with strong selective adsorption properties for the separation of Al(III) and rare earth ions.