Preprations Of Layered Double Hydroxide-Based Composite Functional Materials And Their Properties

Layered double hydroxides (LDHs) are a large type of anionic layered functional materials, which have been intensively investigated recently because of their various applications such as catalysts, sorbents, lithium-ion battery electrodes, and carriers for cellular drug and gene delivery. In this present study, LDH-based composite functional materials were prepared, involving both ZnO/ZnAl2O4 composite microsphere used as photocatalyst and CaAl-dye-LDH/PVA composite nanofiber mat with fluorescent properties. The details involved are presented as follows.1. ZnO/ZnAl2O4 composite microsphere was fabricated by calcinating ZnAl-LDH precursor microsphere. The morphology, size distribution, surface area, pore size distribution were investigated by SEM BET and TEM. The results showed that ZnO/ZnAl2O4 microsphere maintained the hierachically spherical morphology of the corresponding precursor. Photocatalytic property evaluation showed that the ZnO/ZnAl2O4 composite microsphere exhibited enhanced photodegradation performance to methyl blue (MB) and methyl orange (MO), and a preferential photodegradation to MO of the mixture. The enhancement and selectivity were illustrated experimentally in terms of surface acidity. Our results may open up a means to produce promising highly efficient photocatalyst in large amounts.2. Composite nanofibrous mat of sulforhodamine B (SRB) intercalated CaAl-LDH and PVA was prepared by using electrospining. SEM observations showed that a low content of CaAl-SRB-LDH was found to alleviate the agglomerate of LDH. Fluorescent properties showed that within a range of pH value from 7.0 to 9.4 the composite mat exhibited a linear relatiohship against increasing pH value, which can be prosmisingly used for pH detection. In addition, the composite mat retained active in NaCl solution with concentration 400mg/ml which demonstrated a excellent anti-quenching property.