Hollow ZIF-8 nanomaterial prepared via core-shell etching exhibits exceptional adsorption performance for malachite green

Metal-organic frameworks (MOFs) have attracted widespread attention due to their distinctive structural attributes, such as expansive surface areas and the ease of chemical modification. These characteristics endow MOFs with a high degree of versatility, making them suitable for a broad array of applications. Core-shell MOF@MOF structures have emerged as a notable research area, offering a strategy to enhance MOF functionality by depositing one MOF layer over another. In this study, hollow ZIF-8 nanocomposites were successfully synthesized via the etching process of ZIF-67@ZIF-8 structures. It is noteworthy that the nanomaterial exhibits exceptional adsorption capacity, with a maximum adsorption capacity of 7746 mg/g for malachite green (MG), surpassing that of many previously reported adsorbents. Moreover, the recyclability of these nanocomposites is also excellent, demonstrating sustained effectiveness over five adsorption-desorption cycles. The study systematically investigated key factors that influence MG adsorption, such as the amount of adsorbent used and the initial concentration of MG. Additionally, a comprehensive analysis of adsorption kinetics was conducted to gain insights into the adsorption behavior of the nanocomposites. In conclusion, the hollow ZIF-8 nanomaterial prepared via core-shell etching offers a promising platform for the efficient removal of MG, meeting the urgent demand for high adsorption capacity of MG in water treatment.