Modification of Cu/Cr Layered Double Hydroxide by Keggin Type Polyoxometalate as Adsorbent of Malachite Green from Aqueous Solution

Modification of Cu/Cr layered double hydroxides (LDHs) has been conducted by intercalation using Keggin type polyoxometalate [a-SiW12O40]4- to form CuCr-[a-SiW12O40]. The materials were analyzed XRD, FTIR, and surface area analyses. Furthermore, used as selectivity adsorbents cationic dyes such malachite green, rhodamine-B methylene blue. green is more selective than others from an aqueous solution. adsorption showed that the capacity CuCr-[a-SiW12O40] was higher pristine LDHs. process followed pseudo second order kinetic model Langmuir isotherm adsorption. Qmax value reached 55.322 mg/g at 323 K after 100 minutes time. Thermodynamic parameters ΔG, ΔH ΔS confirm endothermic, spontaneous, favorable high temperatures. intercalated material structural stability toward reusability adsorbent