Preferential growth of nickel hydroxide through the controlled release of base from acrylamide-crotonic acid hydrogels

Abstract

This work describes the use of acrylamide/crotonic acid hydrogels as a NaOH dosing system to regulate the preferential growth of Ni(OH)2 nanoparticles. For this purpose, acrylamide/crotonic acid hydrogels were synthesized, in different proportions, in aqueous solutions to 10% monomers, with 1% cross-linking agent, 2% initiator and 3% accelerator. The swelling kinetics was determined at 25 ​°C in distilled water and in aqueous NaOH solutions with pH 13. The hydrogel with NaOH was introduced in NiCl2 solutions, and an easily removable green solid was formed on the surface. It was observed that hydrogels swollen before equilibrium promote the growth of Ni(OH)2 a by stacking blades, as detected by the intensity of the plane (001), while hydrogels that reached equilibrium promote lateral growth along the plane (100). Therefore, hydrogel is able to regulate the preferential growth of Ni(OH)2 particles that were also tested a photocatalyst in the degradation of diclofenac in aqueous solution.