Search

This work reports the synthesis of Au doped iron oxide nanoparticles by co-precipitation method using a cationic polymer as a stabilizer and subsequent coating with graphene oxide (GO) to form the catalytically enhanced GO/Au-Fe3O4 nanoparticles. The nanoparticles were characterized using Fourier Transform Infrared (FT-IR) spectroscopy and X-ray diffraction analysis. The analysis confirms the synthesis of iron oxide nanoparticles and successive coating of GO. The synthesized nanoparticles were used as a catalyst for the reduction of 4-nitrophenol to 4-aminophenol. The effect of temperature on the catalytic activity was studied and the kinetic parameters were calculated. The iron oxide nanoparticles were found to be effective and highly reusable due to their magnetic nature. These nanoparticles can be recovered with the help of a magnet and can be separated effortlessly from the reaction medium after the completion of the reaction.

s Graphene oxide nanocomposites in polyethylene glycol (GO-PEG) were prepared by the ultrasonication assisted suspension. GO was synthesized by the modified Hummer’s method and was then dispersed in PEG to obtain the nanocomposites. The sonication time for the synthesis of the nanocomposites was varied to study its effect on the structural, optical and vibrational properties of the nanocomposites. The synthesized nanocomposites were characterized using UV–visible spectroscopy and Raman spectroscopy. The value of λmax for the synthesized nanocomposites was observed in the range of 230–250 nm. The D and G bands of carbon associated with GO were observed at 1360 cm−1 and 1588 cm−1, along with the 2D band in the micro-Raman spectrum of the GO-PEG nanocomposites.

Gold-Silver (Au-Ag) bimetallic alloy nanoparticles exhibit improved catalytic activity in comparison to the monometallic nanoparticles due to synergistic effect. In this work Au-Ag bimetallic alloy nanoparticles (BNPs) have been supported on alkali activated sand which acts as an inert support material, stabilizes the nanoparticles and prevents their agglomeration. In addition to providing high surface area for adsorption, sand is inexpensive and environmentally benign. Au-Ag alloy nanoparticles were prepared via co-reduction mechanism using polymer as a stabilising agent. Alkali activated sand was coated with the alloy nanoparticles using surface adsorption method. Efficient reduction of 4-Nitrophenol to 4-Aminophenol by NaBH4 in the presence of BNPs supported on alkali activated sand was investigated. Also, the heterogenous nature of the catalyst makes it highly reusable due to its effortless separation from the reaction medium.

In this work, Boron Nitride (BN) nano-particles have been synthesized by hydrothermal treatment using boric acid and an amine-based nitrogen source. BN, a structural analogue of carbon, has garnered considerable attention in the recent years due to its high thermal conductivity, chemical stability, low toxicity, large intrinsic band gap and chemical inertness. The synthesized nanoparticles are non-toxic and heavy metal free exhibiting strong blue fluorescence under UV illumination. The BN nanoparticles were characterized by Transmission Electron Microscopy (TEM), UV–Vis Spectroscopy and Fourier Transform Infrared Spectroscopy (FT-IR) and Zeta Potential measurement. FT-IR analysis revealed the formation of B–N, O–H and N–H bonds. In case of UV–Vis spectroscopy, absorption wavelength was observed at 264 nm. The synthesized nanoparticles may have potential applications in the field of fluorescence sensing and bio-imaging.