Construction of MnO2@ZIF-8 core-shell nanocomposites for efficient removal of Sr2+ from aqueous solution

Novel MnO 2 @ZIF-8 nanocomposites were synthesized for efficient adsorptive removal of Sr 2+ from aqueous solution. ZIF-8 nanoparticles with controlled morphology and size were first synthesized by using amino acids to modulate the crystal nucleation and growth. Then, a layer of MnO 2 nanoparticles were deposited on ZIF-8 surface by using the adsorbed amino acid molecules as binding sites to mediate MnO 2 mineralization and by adjusting the reactive KMnO 4 concentration to control the size and surface density of the MnO 2 nanoparticles . The as-prepared MnO 2 @ZIF-8 nanocomposites showed a core-shell structure and displayed superior performance in Sr 2+ adsorption and removal from aqueous solution. The adsorption process can be described well by the pseudo-second-order equation. The adsorption isotherm accords well with the Langmuir model and the maximum adsorption capacity can reach 65.7 mg/g. The study paves a new way to develop novel inorganic nanocomposites as highly efficient and potential adsorbents for the treatment of radionuclide-containing wastewater.