New antimony substituted Mg-Al layered double hydroxides

Area of Science:

• Materials Science
• Inorganic Chemistry
• Nanotechnology

Background:

• Antimony hydroxide (Sb(OH)3) has not been previously reported due to the thermodynamic preference for antimony oxide (Sb2O3).
• Antimony (III) hydroxide may exist as a hydrated molecular species in equilibrium with Sb2O3 under specific conditions, hindering Sb(3+)-containing layered double hydroxide (LDH) synthesis.

Purpose of the Study:

• To synthesize novel Sb(3+)-containing layered double hydroxides (LDHs).
• To investigate the substitution limit of Sb(3+) in Mg-Al LDH structures.

Main Methods:

• Partial substitution of Al3+ with Sb3+ in Mg-Al LDH.
• X-ray diffraction (XRD) analysis to determine lattice constants.
• Energy-dispersive X-ray spectroscopy (EDS) for chemical formula determination.

Main Results:

• Successful synthesis of Sb-substituted Mg-Al LDH with up to approximately 10% Sb substitution.
• Lattice constants increased with Sb substitution, indicating successful incorporation.
• Solubility limit of Sb3+ in LDH was determined to be around 10%, beyond which Sb2O3 impurity formed.
• Chemical formula Mg4Al(1-x)Sb(x)OH10(CO3)(1/2) x H2O (x ≈ 0.08) was determined.

Conclusions:

• The solubility limit of Sb3+ in LDH structures is approximately 10%.
• Novel Sb(3+)-substituted LDHs were successfully synthesized and characterized.
• This research opens possibilities for new antimony-based functional materials.