Synthesis and properties of layered double hydroxides intercalated with cinnamic acid series organic UV ray absorbents

Organic ultraviolet (UV) ray absorbents such as cinnamic acid (CA), 3,4-dimethoxycinnamic acid (DMOCA) and p-hydroxycinnamic acid (PHCA) were intercalated into Zn2Al layered double hydroxides (Zn2Al-LDHs) by co-precipitation reaction. The organic–inorganic nanocomposites, Zn2Al-LDH/CA, Zn2Al-LDH/DMOCA and Zn2Al-LDH/PHCA were obtained. XRD patterns showed that the basal spacing of Zn2Al-LDH/CA, Zn2Al-LDH/DMOCA and Zn2Al-LDH/PHCA was 1.80, 1.91 and 1.76 nm, respectively. The UV-VIS transmittance spectra of thin films of the samples indicated that all Zn2Al-LDH/organic UV absorbent nanocomposites showed excellent UV ray absorption ability. The catalytic activity studies showed their catalytic activity for the air oxidation of castor oil greatly decreased when the organic UV ray absorbents were intercalated into the interlayer spaces of the Zn2Al-LDHs.