Materials Chemistry and Physics 113 (2009) 491–496 Contents lists available at ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys Synthesis and characterization of (zinc-layered-gallate) nanohybrid using structural memory effect Mohd Zobir bin Hussein a,b,∗ , Mohammad Yeganeh Ghotbi a , Asmah Hj Yahaya b , Mohd Zaki Abd Rahman b a Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia b Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia article info Article history: Received 24 May 2008 Received in revised form 14 July 2008 Accepted 28 July 2008 Keywords: Nanostructures Oxides Heat treatment Layered hydroxide salt abstract The memory effect of calcined zinc hydroxide nitrate, with gallate anion solutions, was studied. The layered hydroxide salt material, zinc hydroxide nitrate was heat-treated at 150–800 ◦ C. XRD analysis showed the growth of the calcined materials in both thickness and diameter occurring simultaneously with increasing calcination temperature. Surface area analysis confirmed this growth. The rehydration behavior of the calcined material was investigated by placing the material in a solution containing gallate anions. The best result for layered hydroxide salt phase reconstruction was obtained for a sample heated at 500 ◦ C and treated with 0.1 mol L -1 anion. PXRD analysis showed the formation of a layered structure material after rehydration process. FTIR and TG confirmed the formation of the host–guest nanohybrid material produced. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Layered double hydroxides (LDHs) have been investigated extensively because of their potential use in industrial and med- ical applications [1,2]. LDHs are minerals with positively charged brucite-type layers of mixed metal hydroxides containing two or more cations. The layers are formed by partial replacement of M 2+ for trivalent M 3+ cations, which would result in positively charged inorganic layers. The excess charge of brucite-like layers can be neu- tralized by anions, which together with water molecules are located in the interlamellar spaces of the inorganic layers [3,4]. Thermal decomposition of LDHs will lead to the formation of well-mixed oxides and thus LDHs are used as precursors for the synthesis of metal oxide nanoparticles in various applications [5,6]. However, layered hydroxide salts, typically zinc hydroxide nitrate (Zn 5 (OH) 8 (NO 3 ) 2 ·2H 2 O) (Card 24-1460) whose structure bears similarity to that of LDHs and has layers constructed solely with one type of cation, has not been studied intensively [7–15]. The thermal decomposition of layered hydroxide salts would lead to the formation of single metal oxides in contrast to mixed metal oxides obtained from LDHs [13]. ∗ Corresponding author at: Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Tel.: +60 38 946 6801; fax: +60 38 943 5380. E-mail address: mzobir@fsas.upm.edu.my (M.Z.b. Hussein). The exposure of calcined LDHs (mixed oxides) to an aqueous solution containing initial anions or new anions may result in the reconstruction of hydrotalcite-like phase [2,16–19]. The so-called memory effect of calcined layered material has not been studied for the formation of zinc layered hydroxide salts as a single-metal hydroxide salt. Gallic acid, 3,4,5-trihydroxybenzoic acid (Fig. 1) is a natural product of the hydrolysis of tannins. It is one of the main phenolic components present in black tea and also exists in natural products such as gallnut, sumac and other plants. It is an anti-mutagenic, anti-carcinogenic and an antimicrobial agent [20–23]. In the present study, reconstruction of zinc oxide, the product of heat-treated zinc layered hydroxide salt (ZLH) in a solution con- taining gallate anions to form ZLH-gallate, an organic–inorganic nanohybrid material (ZLG), was carried out. ZLH was heated at various temperatures to obtain zinc oxide and the structural mem- ory effect was investigated by rehydration of the resultant zinc oxide in a gallate anion solution. Results from the PXRD diffractions patterns, FTIR spectra, TG–DTG curves, surface area and surface morphology studies are discussed here. 2. Experimental All solutions were prepared using de-ionized water. The initial ZLH was synthe- sized from 0.2 mol L -1 Zn(NO3)2 solution. The solution was kept at pH 7.0 ± 0.05 by dropwise additions of 0.2 mol L -1 NaOH solution with vigorous stirring. The precip- itate was filtered, washed with water and acetone and dried in an oven overnight at 70 ◦ C. The sample, ZLH was heated at 150, 200,400, 500, 600, and 800 ◦ C in an elec- tric furnace (Vulcan 3–130) at atmospheric pressure for 5h at a rate of 2 ◦ C min -1 . 0254-0584/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.matchemphys.2008.07.127