Effects of Cation on the Structure and Spectrum Properties of LDHs Materials

The hydrotalcite (LDHs) materials with different kinds of M²⁺ and M³⁺ were prepared by hydrothermal method, and the crystal structure and spectral characteristics of the samples were characterized by X-ray diffraction and UV-VIS-NIR spectrophotometer. The results show that the crystal structure of the samples is related to the type of cations, and affects the NIR spectra of LDHs samples. The introduction of colored cations helps to regulate the spectral curves of hydrotalcite materials. The samples of Mg-Al-LDHs doped with Cr³⁺ has the similar spectral characteristics with natural green plants. Furthermore, fine spectral tuning of Mg-Al-Cr-LDHs samples can be achieved by using binary co-doping.