Search

Sida rhombifolia leaf extract was used to synthesize heterostructured nanocomposites Ag@CuO/ZnO and Ag@CuO/SnO2 by sol–gel combustion method followed by calcination. Through this ecofriendly approach, we could minimize the utilization of toxic chemicals as the bioactive components present in the plant extract act as capping and complexing agents. XRD studies indicated the formation of various crystalline phases of the congeners of the heterostructured nanocomposites. FESEM studies revealed irregular aggregates for AZC of particle size between 100 and 500 nm whereas uniformly arranged distorted spheres for ASC. The UV-DRS spectra helped to assess the reduced band gap energy from tau plot. The PL emission peaks of ZnO and SnO2 point towards the crystal defects in their lattices. The as-prepared ternary nanocomposites have resistivity to the growth of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeroginosa, Streptococcus mutans and Staphylococcus aureus with greater inhibition zones which showed their superior antibacterial activity. They are proved to be excellent photocatalysts for the degradation of hazardous organic dyes into harmless products and reduction of aromatic compounds into useful chemicals. Thus, the facile, low-cost and environmentally sustainable green synthesis provides Ag@CuO/ZnO and Ag@CuO/SnO2 nanocomposites with multifunctional efficacy. [ABSTRACT FROM AUTHOR]

We report the synthesis of nanocomposites of SnO2 with Co3O4, MnO2 and Fe2O3 by co-precipitation method. They are denoted as SnO2/ Co3O4 (SC), SnO2 /MnO2 (SM) and SnO2/Fe2O3 (SF). X-ray diffraction studies indicated the formation of Fe2O3, Co3O4 and MnO2 crystal phases and tetragonal structure of SnO2. FE SEM studies confirmed the formation of binary nanocomposites in which distorted spheres or tubes are embedded in a matrix of agglomerated structures of SnO2 nanoparticles. The UV–Vis-DRS studies revealed the formation of coupled nanocomposites with decreased bandgap energy of the binary systems. The less intense PL peaks point towards the enhanced photocatalytic efficiency of the nanocomposites for the degradation of hazardous organic dyes like methylene blue and malachite green. The formation of hydroxyl radicals was confirmed by the fluorescence test using coumarin probe. High photocurrent measurements also demonstrated good photocatalytic efficiency. The as prepared nanocomposites could be used to bring about the conversion of toxic organic pollutant 4-nitrophenol to 4-aminophenol under green conditions. They showed hostile effect towards the growth of various bacteria which indicated the synergistic effect of the coupled binary metal oxides. The fabrication of heterostructured metal oxide nanocomposites with potential applications as efficient catalyst in effluent treatment and antibacterial agent is a promising strategy. [ABSTRACT FROM AUTHOR]