Synthesis and characterization of SiO2-NiO xerogel nanocomposite prepared by sol–gel method for catalytic reduction of p-nitrophenol

Abstract

This manuscript describes the preparation and characterization of silica-nickel oxide (SiO2-NiO) xerogel nanocomposite and its catalytic application in the hydrogenation of p-nitrophenol. Hydrochloric acid and ammonium hydroxide were used as the acid and base catalyst, respectively during the synthesis of SiO2-NiO. The Fourier Transformation Infra-Red spectroscopic results supported the formation of the silica xerogel skeleton structure with corresponding characteristic peaks of siloxane linkage. The surface of SiO2-NiO xerogel nanocomposite was observed to be porous along with some irregular cracks. The X-Ray diffraction analysis showed that the SiO2-NiO xerogel nanocomposite was amorphous in nature. The synthesized xerogel nanocomposite was employed as a catalyst for the hydrogenation of p-nitrophenol with sodium borohydride in water. The rate of hydrogenation of p-nitrophenol was observed to be increased with the increased amount of catalyst as well as the temperature. The maximum reduction rate of p-nitrophenol was found as high as 0.26 min-1.