Poly(N-isopropylacrylamide)@graphene oxide-Ag responsive hydrogels. Characterization and smart tunable catalytic activity

Thermally responsive hydrogels have drawn significant research attention recently because of their simple use as smart catalyst. Here we design a series of responsive hydrogels that incorporate graphene oxide (GO)-Ag composites into thermo-responsive N-isopropylacrylamide (NIPAM) at different mass ratios. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and UV-visible absorption spectroscopy. Meanwhile, the PNIPAM/GO-Ag hydrogels showed high catalytic activity in the hydrogenation reaction of nitrophenol to aminophenol and acted as a tunable catalyst which the swelling and collapsing could be triggered by small temperature changes around the lower critical solution temperature (LCST) of the hydrogels. The present approach can shed new light on designing of catalytic material like GO-Ag composite responsive hydrogel with promising applications in catalysis.