Layered Double Hydroxide Applications for Heavy Metal Removal

Layered double hydroxides (LDHs) represent a class of two-dimensional lamellar materials characterised by brucite-like metal hydroxide sheets separated by interlayer anions and water molecules. Their general formula, [M2+1–xM3+x(OH)2]x+·(An–)x/n·mH2O, allows for the substitution of divalent and trivalent metal cations to tune layer charge and interlayer composition. This tunability underpins their high anion-exchange capacity and designable surface chemistry, making LDHs highly effective in sequestering heavy metal cations from aqueous media. Removal mechanisms span reversible adsorption via electrostatic attraction and ion exchange, irreversible mineralisation through in-situ precipitation or structural collapse, and selective chelation upon functionalisation with organic ligands. Advances in intercalation of chelating agents, surface modification and hybridisation with carbon-based substrates have substantially enhanced adsorption kinetics, selectivity and recyclability. LDHs have demonstrated rapid uptake of copper, lead, cadmium, chromium and manganese ions across a range of pH values and ionic strengths. Practical applications include industrial wastewater treatment, soil remediation, recovery of valuable metals from agricultural effluents and process water in galvanic plants. Despite challenges such as limited surface area and potential metal leaching, ongoing innovations in composition, morphology control and composite formation continue to reinforce the global significance of LDHs as low-cost, scalable sorbents for heavy metal mitigation and resource recovery.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Layered Double Hydroxide Applications for Heavy Metal Removal publication trend

The graph below shows the total number of articles in layered double hydroxide applications for heavy metal removal across all publications each year (not limited to Nature Index journals).

Technical terms

Layered Double Hydroxide (LDH): A class of lamellar hydroxide materials with positively charged metal hydroxide layers and exchangeable interlayer anions.

Adsorption: The accumulation of ions or molecules at the surface or interlayer of a solid sorbent driven by physical or chemical interactions.

Intercalation: The reversible insertion of ions or molecules into the interlayer galleries of layered host materials.

Anion Exchange Capacity: The ability of a material to exchange interlayer anions with those in solution, critical for selective uptake of negatively charged or chelated species.

Surface Complexation: The formation of chemical bonds between sorbate ions and functional groups at the sorbent surface, enhancing selectivity and stability.

References

1. Recent advances in the detection and removal of heavy metal ions using functionalized layered double hydroxides: a review. Industrial Chemistry and Materials (2023).
2. Layered Double Hydroxides for Remediation of Industrial Wastewater from a Galvanic Plant. Crystals (2020).
3. Mixed Oxide Layered Double Hydroxide Materials: Synthesis, Characterization and Efficient Application for Mn2+ Removal from Synthetic Wastewater. Materials (2020).