Ligand-controlled fabrication of core-shell PdNi bimetallic nanoparticles as a highly efficient hydrogenation catalyst

Green synthesis of triclinic (anorthic) phase AgCoPO4 nanoparticles: optical studies and theoretical modelling

We report the plant-mediated synthesis, structural investigation, optical properties and theoretical modelling of a triclinic (anorthic) phase AgCoPO4 nanoparticles for the first time. As part of green chemistry, the secondary metabolites in the leaf extract of Canna indica were engaged as the reducing/capping agent for the metal nanoparticles. X-ray diffraction (XRD) revealed the presence of an anorthic AgCoPO4 phase, crystallised in a triclinic structure with P -1 space group. Optical studies using UV-vis spectroscopy and photoluminescence are reported. Transmission electron microscopy suggests the formation of quasi-nanocube morphology, unlike the conventional spherically-shaped nanoparticles via plant-mediated reduction method. Elemental composition of the nanohybrid was confirmed by energy-dispersive x-ray spectroscopy (E.D.S.). Evidence of crystallinity was supported by selected area electron diffraction (SAED). Study of the dynamic anisotropy of the nanohybrid at optimised state suggests its proposed application as optical material in colourimetric metal nanoparticles-mediated sensors.

Bimetallic Pd-Au/TiO2 Nanoparticles: An Efficient and Sustainable Heterogeneous Catalyst for Rapid Catalytic Hydrogen Transfer Reduction of Nitroarenes

Anilines are one of the important chemical feedstocks and are utilized for the preparation of a variety of pharmaceuticals, agrochemicals, pigments, and dyes. In this context, the catalytic reduction of nitro functionality is an industrially vital process for the synthesis of aniline derivatives. Herein, we report an efficient nanosized bimetallic Pd-Au/TiO₂ nanomaterial which is proved to be quite efficient for rapid catalytic hydrogen transfer reduction of nitroarenes into corresponding amines. Significantly, the reduction process is successful under solvent-free and mild green atmospheric conditions. Bimetallic Pd-Au nanoparticles served as the active center, and TiO₂ played as a support in hydrogen transfer from the source hydrazine monohydrate. Typical results highlighted that the reactions were very rapid and the products were obtained in good to excellent yields. Significantly, the process was successful in the presence of a very low amount catalyst (0.1 mol %). Furthermore, the reaction showed good chemoselectivity and compatiblity with double or triple bond, aldehyde, ketone, and ester functionalities on the aromatic ring. Typical results indicated the true heterogeneous nature of the Pd-Au/TiO₂ nanocatalyst, where the catalyst retained the activity, without loss of its activity.