Herein, a simple wet-chemical pathway has been demonstrated for the synthesis of silver nanoparticle conjugated reduced graphene oxide nanosheets where dimethylformamide (DMF) is judiciously employed as an efficient reducing agent. Altogether, DMF reduces both silver nitrate (AgNO3) and graphene oxide (GO) in the reaction mixture. Additionally, the presence of polyvinylpyrolidone (PVP) assists the nanophasic growth and homogeneous distribution of the plasmonic nanoparticle Ag(0). Reduction of graphene oxide and the presence of aggregated Ag NPs on reduced graphene oxide (rGO) nanosheets are confirmed from various spectroscopic techniques. Finally, the composite material has been exploited as an intriguing platform for surface enhanced Raman scattering (SERS) based selective detection of uranyl (UO2(2+)) ion. The limit of detection has been achieved to be as low as 10 nM. Here the normal Raman spectral (NRS) band of uranyl acetate (UAc) at 838 cm(-1) shifts to 714 and 730 cm(-1) as SERS bands for pH 5.0 and 12.0, respectively. This distinguished Raman shift of the symmetric stretching mode for UO2(2+) ion is indicative of pronounced charge transfer (CT) effect. This CT effect even supports the higher sensitivity of the protocol toward UO2(2+) over other tested oxo-ions. It is anticipated that rGO nanosheets furnish a convenient compartment to favor the interaction between Ag NPs and UO2(2+) ion through proximity induced adsorption even at low concentration.

Blue solution of copper(II) acetylacetonate complex, [Cu(acac)(2)] in dichloromethane (DCM) and an aqueous alkaline solution of thioacetamide (TAA) constitute a biphasic system. The system in a screw cap test tube under a modified hydrothermal (MHT) reaction condition produces a greenish black solid at the liquid-liquid interface. It has been characterized that the solid mass is an assembly of hexagonal copper sulfide (CuS) nanoplates representing a hierarchical structure. The as-synthesized CuS nanoplates are well characterized by several physical techniques. An ethanolic dispersion of CuS presents a high band gap energy (2.2 eV) which assists visible light photocatalytic mineralization of different dye molecules. Thus a cleanup measure of dye contaminated water body even under indoor light comes true.

This paper reports the nucleation and growth of 2D δ-MnO 2 nanosheets from a simple wet chemical reaction at low temperature. The reaction between aqueous KMnO 4 and pure ethyl acetate constitutes a new a biphasic platform for product evolution. Then the synthesized δ-MnO 2 nanosheets undergo shape transformation to 1D α-MnO 2 nanowires in the same pot via a dissolution−recrystallization mechanism. The detailed growth mechanism of nanosheet formation and the morphology transformation are described in this paper. Moreover, this low temperature technique can be used to produce ultralong α-MnO 2 nanowires in industrial amounts which are difficult to synthesize by conventional high temperature methods. In this method, we have prepared 25.00 g of α-MnO 2 nanowires in our nanomaterial laboratory from 18 batches. Lastly, solvent-free catalytic activity of α-MnO 2 nanowires is investigated for the hydrolysis of benzonitrile to benzamide in one step.

Adsorption of dopamine (DA) on a Au core -Ag shell bimetallic nanocolloidal surface has been investigated using surface-enhanced Raman spectroscopy (SERS). The normal Raman spectra (NRS) of DA molecules in bulk and in aqueous solution have been investigated in depth. The vibrational signatures, as observed from the Raman and FTIR spectra of the molecule, have been assigned from the potential energy distributions. The pH-dependent NRS of the DA molecule in aqueous solution has been recorded to elucidate the protonation effect and preferential existence of different forms of the molecule. The pH-dependent SERS spectra of the molecule adsorbed on the bimetallic Au core -Ag shell nanocolloidal surface are also reported. The enhancement of bands in the pH-dependent SERS spectra suggests that the molecules are adsorbed onto the bimetallic Au core -Ag shell surface with the molecular plane tilted with respect to the silver surface of Au core -Ag shell bimetallic nanoparticles. The model study authenticates the spectral disposition and orientation of the molecule. Thus, experiment and theory keep abreast of the variety of DA structures envisaged from SERS studies on a new substrate.