AgPt nanoparticles supported on magnetic graphene oxide nanosheets for catalytic reduction of 4‐nitrophenol: Studies of kinetics and mechanism

Ag x Pt 100− x ( x = 0, 25, 50, 75 and 100) nanoparticles were grown on the surface of magnetic graphene oxide nanosheets (Fe 3 O 4 @GO) for the first time. The as‐prepared nanocomposites were characterized using various techniques such as Fourier transform infrared spectroscopy, powder X‐ray diffraction, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller surface area analysis, vibrating sample magnetometry and thermogravimetric analysis. The Fe 3 O 4 @GO‐Ag x Pt 100− x catalysts were applied in the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol using sodium borohydride (NaBH 4 ). The synthesized nanocomposites exhibited excellent catalytic performance in the reduction of 4‐NP with high recyclability for five consecutive runs. The Fe 3 O 4 @GO‐Ag 75 Pt 25 nanocomposite exhibited the best catalytic activity with a rate constant as high as 140.6 × 10 −3 s −1 . The obtained kinetic data were modelled with the Langmuir–Hinshelwood equation. The energy of activation and thermodynamic parameters including enthalpy, entropy of activation and activation Gibbs free energy were calculated.