Hectogram-scale green synthesis of hierarchical 4A zeolite@CuO x (OH) (2-2 x ) (0 ≤ x < 1) nanosheet assemblies core-shell nanoarchitectures with Superb Congo red adsorption performance.

Delicate design of hierarchical nanoarchitectures has become a highly effective strategy to develop novel adsorbents with improved adsorption capacity. Herein, hectogram-scale green fabrication of hierarchical 4A zeolite@CuO x (OH) (2-2 x ) (0 ≤ x < 1) nanosheet assemblies core-shell nanoarchitectures (4A-Cu- T , T was the calcination temperature) with terrific Congo red (CR) dye adsorption performance was achieved through a simple, template-free and surfactant-free hydrothermal approach. A series of characterization techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction and photoelectron spectroscopy demonstrated that all resultant adsorbents featured a core-shell structure with 4A zeolite as core ingredients and CuO x (OH) (2-2 x ) (0 ≤ x < 1) nanosheet assemblies as shell components. The adsorption experimental results pointed out that 4A-Cu-300 with a maximum adsorption capacity of 512.987 mg g -1 showed the best adsorption performance amongst all as-prepared adsorbents, and the adsorption capacity of shell component-CuO x Cu(OH) (2-2 x ) (0 ≤ x < 1) nanosheet assemblies was calculated up to 3685.500 mg g -1 . The shell thickness and phase ratio of CuO and Cu(OH) 2 in CuO x (OH) (2-2 x ) (0 ≤ x < 1) nanosheet assemblies played key roles in improving the adsorption capacity. The successive tests suggested that the "carbon deposition" resulted in the decreased adsorption capacity of first-regenerated adsorbents, but little variance in adsorption performance among regenerated samples demonstrated the good stability of such adsorbents. This work unlocks a method for the rational design of high-performance adsorbents via delicate decoration of poor-performance materials with nanosheet assemblies, which will endow the non-active materials with enhanced adsorption properties.