Preparation and utilization of Keggin-type polyoxometalate intercalated Ni–Fe layered double hydroxides for enhanced adsorptive removal of cationic dye

Abstract

The Ni-Fe layered double hydroxide (LDH) intercalated by Keggin-type polyoxometalate (POM) of SiW 12 O 40 4− was investigated for the first time. The synthesized Ni-Fe LDH and Ni-Fe POM were characterized by XRD, FT-IR, and N 2 adsorption-desorption isotherm to identify the intercalation process as well as their surface morphology. The obtained results indicated that after intercalated by POM, the interlayer distance of the LDH expanded due to the insertion of POM anion and removal of some native NO 3 − anion in the interlayer space. Moreover, the increment of the BET surface area of the material after intercalation indicated the opening of the interlayer space that beneficial for the adsorption process. The study on the malachite green adsorption onto the synthesized materials showed that POM intercalated LDH has better adsorption capacity than the original LDH, where the adsorption kinetic was better described by pseudo second order model than the pseudo first order model.

Preparation of copper aluminum-biochar composite as adsorbent of malachite green in aqueous solution

“…Layered double hydroxide (LDH) is the anionic synthetic clay with general formula [M2+1−xM3+x (OH)2]+xAx/n−n •mH2O with M2+ containing divalent (Cu2+, Mg2+, Zn2+ and Ca2+) and M3+ containing trivalent metals ion (Al3+, Cr3+ and Fe3+) [16]. LDH has widely used as adsorbent to remove heavy metals, organic compounds, and dyes from wastewater.…”

“…According to Lesbani et al (2020), NiFe LDH has been modified by intercalation process using polyoxometalate to enhanced adsorptive removal of malachite green. The adsorption capacity of modified LDH is higher than pristine [16]. The composites treatment also used to improve the adsorption capacity of cationic dyes by incorporation of carbon-based compounds such as biochar into LDH [19].…”

Copper Aluminum Layered Double Hydroxide Modified by Biochar and its Application as an Adsorbent for Procion Red

“…Several methods have been studied to enhance the adsorption activity for dyes, such as LDH modifications. Lesbani and others [19] employed nickel-iron LDH intercalated with polyoxometalates to remove cationic dyes. The adsorption capacity of the modified LDH was higher than that of the pristine LDH.…”

Adsorptive Removal Methylene-Blue Using Zn/Al LDH Modified Rice Husk Biochar

“…The ∆H for the adsorption in the range of 17.309-23.697 kJ/mol and less than 100 kJ/mol. Thus the adsorption in this research is categorized as physical adsorption [29].…”