Photoluminescence of colloids of pristine MgAl layered double hydroxides

We present an unexpected photoluminescence (PL) phenomenon for colloids of pristine MgAl layered double hydroxides (LDHs). Moreover, the PL spectra displayed little dependency on LDH platelet size, excitation wavelength or colloid concentration. The possible mechanism was discussed mainly in terms of specific surface areas, numerous surface defects and excited electron-hole recombination.