Introduction . In recent years, two-dimensional nanomaterials have been widely studied and used as attractive candidates for the construction of heterogeneous solid catalysts, electrodes, adsorbents, metal-sulfur batteries, etc1 , 2 , 3. Double-layered hydroxides known for more than a decade, are abundant in nature and easily extracted, and represent a large class of anion- and cation-exchangeable layered structures with the general formula [M 2+ (1-x) Mx 3+ (OH) 2 is](An...