The main source of nitroaromatic compounds in the nature is anthropogenic activities. In this present report, a facile and green method was employed to fabricate highly efficient catalysts to turn toxic nitroaromatics to more safe and precious aminoromatics. The novel Fe 3 O 4 /Ag@Ca–Al LDH hybrid (FAL hybrid) synthesized by the magnetite and Ag nanoparticles supported on layer double hydroxide (LDH) through electrostatic adsorption and composite of this hybrid synthesized by stabilization with starch via an in situ growth method. Furthermore, the synthesis of magnetite/ LDH/ xanthan bionanocomposite and the comparison of that with starch based bionanocomposite reveald the role of support by LDH and starch in decrease the size as well as the agglomeration of particles. The elemental composition, thermal behavior, crystal structure, morphology and size distribution of FAL hybrid and Fe 3 O 4 /Ag@Ca?Al LDH@Starch bionanocomposite (FALS-BNC) characterized by FT-IR spectroscopy, TGA, X-ray diffractometry, FE-SEM, EDX, elemental mapping, and TEM analysis. The FALS-BNC TEM images showed nanoparticles with a size of ?5nm and homogeneous distribution of hybrid within biopolymer. Besides, TGA revealed the effective role of starch in the thermal resistance of bionanocomposite and also showed a greater char yield against xanthan bionanocomposite. The reduction reaction of 4-nitrophenol in the presence of Fe 3 O 4 /Ag@Ca–Al LDH hybrid and FALS-BNC catalysts completed in 420 and 480 seconds and indicated that both of them have high catalytic activity due to their large surface areas and well distribution of Ag nanoparticles through the LDH and biopolymer. The comparison rate kinetics study between 4-nitrophenol and 2-nitrophenol showed that the FALS-BNC has higher potential in the case of the para derivative. More than that, FAL hybrid reduced 3-nitroanilin, 4-nitroanilin and 1,2-dinitrobenzene up to 98%. At the end, the catalysts recovered easily by the magnetic field and reused at least five times, maintaining relatively good activity.
