Easily scalable synthesis of Ni nanosols suitable for the hydrogenation of 4-nitrophenol to p-aminophenol under mild condition

Abstract

Ni nanoparticles with a dimension ranging between 80 and 200nm were synthesized by a microwave-assisted polyol route. The reaction was carried out at 200°C in diethylenglycol (DEG) in the presence of a binary chelating agent system (polyvinylpyrrolidone PVP and dodecylamine DDA), in order to obtain stable and highly concentrated nanosols whose ratio was carefully optimized. Stable suspensions were produced with the future prospect of improving the performance of the anodic layer in solid oxide fuel cells (SOFCs), in which the metal is employed as catalyst. Studying the influence of different reaction times on the final product, it was possible to identify the reaction path that goes through the formation, after 10min, of crystalline Ni-glycolate that turns completely into crystalline Ni metal after 20min. The as obtained Ni nanoparticles were characterized by XRD, TG–DTA, FT-IR, TEM. Preliminary tests on their catalytic and electrochemical activities were carried out by studying the hydrogenation of 4-nitrophenol (4-NP) to p-aminophenol (4-AP) in the presence of NaBH4 as probe reaction and by calculating the electrochemically active surface area (AECSA) with cyclic voltammetry.