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

Abstract

AgxPt100−x (x = 0, 25, 50, 75 and 100) nanoparticles were grown on the surface of magnetic graphene oxide nanosheets (Fe3O4@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 Fe3O4@GO‐AgxPt100−x catalysts were applied in the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol using sodium borohydride (NaBH4). The synthesized nanocomposites exhibited excellent catalytic performance in the reduction of 4‐NP with high recyclability for five consecutive runs. The Fe3O4@GO‐Ag75Pt25 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.

Green Synthesis of an Activated Carbon-Supported Ag and ZnO Nanocomposite for Photocatalytic Degradation and Its Antibacterial Activities

“…The reduction reaction of 4-nitrophenol was further tested with both AgNPs and ZnONPs. It is known that in alkaline medium, the absorption peak at 317 nm for 4-nitrophenol will be shifted to 400 nm due to the formation of nitrophenolate ions [23,24,61]. Therefore, the conversion of 4-nitrophenol to nitrophenolate ions catalyzed by AgNPs and ZnONPs can be tested by following the change of absorption peak of nitrophenolate ions at 400 nm, and that of 4-aminophenol at 317 nm [24].…”

“…4-Nitrophenol is extensively used in many industries to make explosives, wood protection products, dyes, and herbicides. 4-Nitrophenol is considered as a major pollutant due to its high solubility and stability in water [23]. Recently, the degradation of 4-nitrophenol has become an essential topic since it produces an extremely useful intermediate, 4-aminophenol, which is widely used in the synthesis of drugs such as paracetamol and acetaminophen [24].…”

On the Remarkable Performance of Silver‐based Alloy Nanoparticles in 4‐Nitrophenol Catalytic Reduction

“…Others reported on the electrocatalytic activity in the oxidation of methanol, formic acid, carbon monoxide, and the oxygen reduction reaction . Some studies focused on Ag−Pt BMNP preparation and characterization; However, very few reports have focused on Ag−Pt BMNP catalyzed reduction of 4‐NP . In this work, we produced various compositions of unsupported BMNPs of Au−Pt and Ag−Pt, providing tunable surface properties upon alloying to achieve an optimal catalyst‐reactant interaction specifically for enhancing the 4‐NP catalytic reduction.…”

Fabrication of carboxymethylated cellulose fibers supporting Ag NPs@MOF‐199s nanocatalysts for catalytic reduction of 4‐nitrophenol

“…4‐nitrophenol (4‐NP) compound has been identified as one of priority organic pollutants in both industrial and agricultural wastewater, whereas its reduction product, 4‐aminophenol (4‐AP) with less toxicity, has versatile industrial applications, such as intermediates for pharmaceutical, dyeing agents and anticorrosion lubricants . As a result, various methods have been employed to remove 4‐NP from wastewater, including chemical oxidation, biological treatment, membrane treatment, catalytic degradation, etc . Among them, the catalytic reduction of 4‐NP into 4‐AP has been regarded as a preferred one due to its inherent environmental friend and economic efficiency …”

“…However, owing to high surface energy, metal nanoparticles, including Ag NPs, are thermodynamically unstable and tend to aggregate, thus leading to a remarkable loss in their catalytic activity . In order to remedy this problem, it is suggested that the strategy of immobilizing metal NPs onto porous structures such as cellulose nanofibers, carbon materials and polymeric matrices is effective in decreasing the aggregation issue above.…”