Babita Baruwati

Nanoparticle-supported and magnetically recoverable nickel catalyst: a robust and economic hydrogenation and transfer hydrogenation protocol

A magnetic nanoparticle-supported leach-proof Ni catalyst was readily prepared from inexpensive starting materials which catalyzes various hydrogenation and transfer hydrogenation reactions; high catalytic activity and ease of recovery using an external magnetic field are additional eco-friendly attributes of this catalytic system.

Self-Assembly of Metal Oxides into Three-Dimensional Nanostructures: Synthesis and Application in Catalysis

Nanostructured metal (Fe, Co, Mn, Cr, Mo) oxides were fabricated under microwave irradiation conditions in pure water without using any reducing or capping reagent. The metal oxides self-assembled into octahedra, spheres, triangular rods, pine, and hexagonal snowflake-like three-dimensional morphologies. Pine-structured nano-iron oxides were studied as a novel support for various catalytic organic transformations.

Glutathione promoted expeditious green synthesis of silver nanoparticles in water using microwaves

Silver nanoparticles ranging from 5–10 nm in size have been synthesized under microwave irradiation conditions using glutathione, an absolutely benign antioxidant that serves as the reducing as well as capping agent in aqueous medium. This rapid protocol yields the nanoparticles within 30–60 s at a power level as low as 50 W. The effect of microwave power on the morphology of ensuing silver nanoparticles is investigated for this green and sustainable procedure which is adaptable for the synthesis of palladium, platinum and gold nanoparticles.

Magnetically separable nanocomposites with photocatalytic activity under visible light for the selective transformation of biomass-derived platform molecules

Novel magnetically separable TiO2-guanidine-(Ni,Co)Fe2O4 nanomaterials were prepared and characterised by a series of techniques including XRD, SEM, TEM, N2 physisorption as well as XPS and subsequently tested for their photocatalytic activities in the selective transformation of malic acid in aqueous solution. The modification with guanidine, which remarkably decreases the band gap of the metal oxide, was found to have a significant effect in the photocatalytic activity of the materials under visible light, showing a remarkably superior activity to that of the commercial Degussa P25. These materials are also envisaged to have interesting photocatalytic activities under sunlight.

Magnetically separable nanoferrite-anchored glutathione: aqueous homocoupling of arylboronic acids under microwave irradiation

A highly active, stable and magnetically separable glutathione-based organocatalyst provided very good to excellent yields to symmetric biaryls in the homocoupling of arylboronic acids under microwave irradiation.

High value products from waste: grape pomace extract--a three-in-one package for the synthesis of metal nanoparticles.

Metal nanoparticles of Au, Ag, Pd, and Pt have been synthesized in aqueous media using red grape pomace as a reducing agent and a capping agent. The particles are formed within a few seconds when exposed to microwave irradiation at a power level as low as 50 W. Particles could be formed at room temperature, but they tend to be amorphous in nature except for gold. A detailed study on the morphology of the ensuing particles with various reaction conditions has been carried out.

Visible light induced photobleaching of methylene blue over melamine-doped TiO2 nanocatalyst

TiO(2) doping with N-rich melamine produced a stable, active and visible light sensitized nanocatalyst that showed a remarkable efficiency towards the photobleaching of a model compound - methylene blue (MB) in aqueous solution. The photobleaching followed a mixed reaction order kinetics with the distinctive induction and acceleration periods.

Nanostructured Membranes for Enzyme Catalysis and Green Synthesis of Nanoparticles

Macroporous membranes functionalized with ionizable macromolecules provide promising applications in high capacity toxic metal capture, nanoparticle syntheses, and catalysis. Our low-pressure membrane approach has good reaction and separation selectivities, which are tunable by varying pH, ionic strength, or pressure. The sustainable green chemistry approach under ambient conditions and the evaluation of a reactive poly(acrylic acid) (PAA)-modified polyvinylidene fluoride (PVDF) membrane is described. Two distinct membrane types were obtained through different methods: 1) a stacked membrane through layer-by-layer assembly for the incorporation of enzymes (catalase and glucose oxidase), providing tunable product yields and 2) Fe/Pd nanoparticles for degradation of pollutants, obtained through an in situ green synthesis. Bioreactor-nanodomain interactions and mixed matrix nanocomposite membranes provide remarkable versatility compared to conventional membranes.

Chapter 7:Microwave-assisted Synthesis of Nanomaterials in Aqueous Media

This chapter summarizes the synthesis of a variety of nanomaterials under microwave irradiation conditions using water as a solvent. Production of different nanomaterials including Au, Ag, Pd, Pt, TiO2, ZnO, magnetic oxides and quantum dots have been discussed. The chapter tries to look into the possibilities and difficulties related with the methods reported by various research groups. Application of these nano-materials in catalysis was also reviewed.