Synthesis Of Magnetical Catalysts Based On Complex Of Ferroferric Oxide And Carbon Materials And Their Applications

This paper mainly studied a series of magnetic catalysts based on the composite of Fe₃O₄and carbon materials and their applications in Carbon-Carbon coupling reaction andelectrochemical catalytic reaction, which mainly contains three parts as follows:（1） Fe₃O₄@CF@Pd, the catalyst with high palladium （Pd） coverage （Pd mol%=25%）was prepared and used to catalyze the Suzuki coupling reaction. First, Fe₃O₄@CF, themagnetic support coated with polyhydroxy carbon film （CF） was synthesized by the thermaltreatment of glucose and Fe₃O₄nanoparticles. Then, Pd nanoparticle was deposited to thesupport by refluxing reduction. The effect of reaction time, base, Pd coverage and pH value tothe catalyst activity and reusability were studied. The results indicated that Fe₃O₄@CF@Pdcan catalyze Suzuki coupling reaction efficiently under proper conditions. The yield can be upto94.74%, and it still can be87.65%after three continuous times.（2） Palladium （Pd） catalyst Fe₃O₄-GO-Pd is prepared by a two-step process, thecomposition of the supporter Fe₃O₄-GO and the deposition of Pd nanoparticles. Proper base,best Pd capacity and pH value are discussed and the catalyst is demonstrated exhibiting muchbetter activity （the yield even up to100%） toward Suzuki coupling reaction compared withthe catalyst Fe₃O₄@CF@Pd （CF, for short of carbon film）. Moreover, due to the magneticsupporter, the catalysts can be easily separated by an external magnetic field, which greatlysimplify the recovery for catalysts. In addition, it can be reused for several times withoutsufficient loss of its catalytic activity, which should be attributed to the great specific surfacearea and excellent stability of graphene oxide （GO）.（3） A sensitive non-enzyme hydrogen peroxide （H₂O₂） sensor was fabricated based ongraphene-Fe₃O₄composite （GR-Fe₃O₄）. The GR-Fe₃O₄was synthesized by electrochemicalreduction of graphene oxide-Fe₃O₄composite （GO-Fe₃O₄） which was characterized by X-raydiffraction （XRD） and fourier transform infrared spectrophotometer （FTIR）. Electrochemicalinvestigations indicated that GR-Fe₃O₄exhibited high peak current and low overpotentialtowards the reduction of H₂O₂. GR-Fe₃O₄modified electrode displayed a wide linear range(5.0×10^-72.89×10^-3M), low limit of detection (1.3×10^-7M) and good selectivity for H₂O₂detection with a much higher sensitivity (22.27μA·mM^-1·cm^-2) than that of Fe₃O₄nanoparticles （NPs） or GO-Fe₃O₄modified electrode.