Synthesis And Photochemical Properties Of Organic UV Ray Absorbents-Pillared Layered Double Hydroxide Composites

Several organic UV ray absorbers, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (HMBSA), 4-hydroxy-3-methoxycinnamic acid (HMCA) and 4, 4 ' -diaiminostilbene-2, 2 ' -disulfonic acid (DASDSA), in their anionic forms, were intercalated into the interlayer spaces of the Zn2Al-layered double hydroxides(Zn2Al-LDHs), the organic-inorganic composite materials, Zn2Al-LDH/HMBSA, Zn2Al-LDH/HMCA and Zn2Al-LDH/DASDSA, were obtained, and the organic anions in the interlayer still maintained their original structures. The Zn2Al-LDH/organic UV absorbent composites showed excellent UV-shielding ability and transparency in the visible light region by the UV-Vis film transmittance spectra. In addition, the photocatalytic activity of the Zn2Al-LDH/organic UV absorbent composites for phenol photodegradation was very low. When the organic UV ray absorbers in their anionic forms were intercalated into the layers of the Zn2Al-LDHs, their UV absorption ability increased further, and their oxidation catalytic activity for the air oxidation of castor oil greatly decreased.