Preparation, characterization and heterogeneous catalytic applications of GO/Fe₃O₄/HPW nanocomposite in chemoselective and green oxidation of alcohols with aqueous H₂O₂

Abstract

Fe 3 O 4 /HPW) was prepared by linking amino-functionalized Fe 3 O 4 nanoparticles (Fe 3 O 4 -NH 2 ) on the graphene oxide (GO), and then grafting 12tungstophosphoric acid (H 3 PW 12 O 40 ) on the graphene oxide-magnetite hybrid (GO-Fe 3 O 4 -NH 2 ). The obtained GO/Fe 3 O 4 /HPW nanocomposite was well characterized with different techniques such as FT-IR, TEM, SEM, XRD, EDX, TGA-DTA, AGFM, ICP and BET measurements. The used techniques showed that the graphene oxide layers were well prepared and the various stages of preparation of the GO/Fe 3 O 4 /HPW nanocomposites successfully completed. This new nanocomposite displayed excellent performance as a heterogeneous catalyst in the oxidation of alcohols with H 2 O 2 . The as-prepared GO/Fe 3 O 4 / HPW catalyst was more stable and recyclable at least five times without significantly reducing its catalytic activity.

Modified Nanocarbons for Catalysis

“…The immobilization of amino‐functionalized silica‐coated Fe 3 O 4 onto GO gave rise to the support material used for the immobilization of phosphotungstic acid. The so‐obtained material 172 was used as heterogeneous and magnetically recoverable catalyst for the oxidation of alcohols in aqueous H 2 O 2 (Scheme ) . Catalytic activity of material 172 in the oxidation of primary and secondary benzylic alcohols was very good with complete selectivity towards the formation of the corresponding aldehydes and ketones.…”

A Facile Synthesis of ZrOx-MnCO3/Graphene Oxide (GRO) Nanocomposites for the Oxidation of Alcohols using Molecular Oxygen under Base Free Conditions

“…On the contrary, GRO was found to be thermally unstable, wherein at 100 °C, it starts to lose absorbed moisture and volatile impurities. Approximately 43% of the weight was lost in the range of 200 to 370 °C, which could be due to pyrolysis of the oxygenated groups [41]. In comparison, the (1%)ZrOx-MnCO3 on the GRO support showed a much improved thermal stability.…”

The application of copolymer‐coated graphene oxide‐Fe3O4 in the highly efficient synthesis of 2′‐aminospiro[indeno[1,2‐b]quinoxaline‐11,4′‐[4'H] pyran]‐3′‐carbonitrile and 2′‐aminospiro[indeno‐2,4′‐[4'H]pyran]‐3′‐carbonitrile

“…They have found uses in sensors, superparamagnetic relaxometry, magnetic resonance imaging (MRI) in medicine, and the development of new, green, and reusable catalysts. [ In these applications, MNPs are coated by a layer of protective material made of organic or inorganic compounds, such as polymers, silica, some metals (e.g. gold), and some other modifiers.…”