Preparation and properties of hierarchical Al–Mg layered double hydroxides as UV resistant hydrotalcite

Abstract

Anti-ultraviolet Mg–Al hydrotalcite samples (MgAl–P-LDH) with 4-metoxybenzoic acid (PMOBA) ion intercalation were prepared by high temperature reduction method. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Visible absorption spectrophotometry, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry. SEM images indicate that the UV-resistant MgAl–P-LDH had a layered structure. The results of X-ray diffraction analysis showed that the purity of MgAl–P-LDH sample was higher. Compared to MgAl-LDH, the characteristic peak for MgAl–P-LDH shifted towards small angle of 2θ, and it was found that the PMOBA ions have been inserted into the interlayer of MgAl hydrotalcite. The infrared spectra also showed that PMOBA ions were successfully intercalated within Mg–Al hydrotalcite layer. The ultraviolet absorption of MgAl–P-LDH was better than that of PMOBA and MgAl-LDH with the wavelength range of 225–325 nm, and the maximum absorption over 80% was observed.