Synthesis of ultra-small Rh nanoparticles congregated over DNA for catalysis and SERS applications.

Exploration of rare earth metals for the Surface Enhanced Raman Scattering (SERS) is greatly preferred to identify probe molecules even at nano molar level. Highly stable Rh nanoparticles (NPs) which are ultra-small size have been prepared within 20 min of reaction time as a colloidal solution using a bio-molecular scaffold DNA and NaBH as a reducing agent under room temperature. While keeping metal ion concentration fixed and by making difference in DNA concentration, three different sets of Rh@DNA such as 0.

An electrochemical sensor for homocysteine detection using gold nanoparticle incorporated reduced graphene oxide.

In this work, we report a methodology for the quantification of Homocysteine (HcySH) at neutral pH (pH-7.0) using Au nanoparticles incorporated reduced graphene oxide (AuNP/rGO/GCE) modified glassy carbon electrode. The modified electrode was characterized using SEM and XRD techniques.

Morphology dependent catalysis and surface enhanced Raman scattering (SERS) studies using Pd nanostructures in DNA, CTAB and PVA scaffolds.

Palladium nanoparticles (Pd NPs) of three different morphologies viz., nanocubes with cetyltrimethylammonium bromide (CTAB), nanowires with polyvinyl alcohol (PVA) and Pd NPs with deoxyribonucleic acid (DNA) scaffolds were synthesized by UV-irradiation. Catalysis and surface enhanced Raman scattering (SERS) studies were done with the synthesized morphologically distinct Pd nanostructures for the very first time.

Self-Assembled Molecular Hybrids of CoS-DNA for Enhanced Water Oxidation with Low Cobalt Content.

Water oxidation in alkaline medium was efficiently catalyzed by the self-assembled molecular hybrids of CoS-DNA that had 20 times lower Co loading than the commonly used loading. The morphological outcome was directed by varying the molar ratio of metal precursor Co(Ac) and DNA and three different sets of CoS-DNA molecular hybrids, viz. CoS-DNA(0.

Shape-selective catalysis and surface enhanced Raman scattering studies using Ag nanocubes, nanospheres and aggregated anisotropic nanostructures.

Three morphologies of silver nanoparticles (Ag NPs) such as nanocubes, aggregated anisotropic Ag NPs, and nanospheres were prepared using polystyrene sulfonate (PSS) and citrate as stabilizing agents utilizing a simple wet-chemical and microwave heating route respectively. Ag nanocubes were prepared within one min through microwave heating whereas anisotropic Ag NPs and spherical Ag NPs via 5 and 30min of normal stirring at room temperature (RT) respectively. The shape effect of three different morphologies of Ag NPs were examined in catalysis reaction and in surface enhanced Raman scattering (SERS) studies.

Core-Oxidized Amorphous Cobalt Phosphide Nanostructures: An Advanced and Highly Efficient Oxygen Evolution Catalyst.

We demonstrated a high-yield and easily reproducible synthesis of a highly active oxygen evolution reaction (OER) catalyst, "the core-oxidized amorphous cobalt phosphide nanostructures". The rational formation of such core-oxidized amorphous cobalt phosphide nanostructures was accomplished by homogenization, drying, and annealing of a cobalt(II) acetate and sodium hypophosphite mixture taken in the weight ratio of 1:10 in an open atmosphere. Electrocatalytic studies were carried out on the same mixture and in comparison with commercial catalysts, viz.

Tuning of intrinsic antiferromagnetic to ferromagnetic ordering in microporous α-MnO by inducing tensile strain.

By employing first principles density functional calculations, we investigated an α-MnO compound with a tunnel framework, which provides an eminent platform to alter the intrinsic antiferromagnetic (AFM) to ferromagnetic (FM) ordering, through the introduction of chemical or mechanical tensile strain. Our calculations further showed that the strength of FM ordering increases until 10% triaxial tensile strain. Since long range FM ordering is induced, it is realized to be superior as compared to the experimentally observed short-range FM ordering in oxygen-deficient compound.

Ultra-small rhenium nanoparticles immobilized on DNA scaffolds: An excellent material for surface enhanced Raman scattering and catalysis studies.

Highly Sensitive and ultra-small Rhenium (Re) metal nanoparticles (NPs) were successfully stabilized in water by the staging and fencing action of the versatile biomolecule DNA that resulted in two distinct aggregated chain-like morphologies with average grain sizes of 1.1±0.1nm and 0.

First principles calculations on oxygen vacant hydrated α-MnO2 for activating water oxidation and its self-healing mechanism.

Understanding the mechanism behind water oxidation is the prime requirement for designing better catalysts for electrochemical energy devices. In this work, we demonstrate by employing first principles calculations that an initial step of water oxidation is observed to be associated with the dissociation of water dimers into hydronium and hydroxide ions, in the tunnel of a hydrated α-MnO2 compound with an oxygen vacancy. The former ion is intercalated within the network, while the latter ion occupies the oxygen vacant site and interacts strongly with the Mn atoms.

An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO2-RuO2-TiO2 anodes), lead to discoloration by 92% and 89%, respectively, in 100min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition.

Shape-selective synthesis of Sn(MoO4)2 nanomaterials for catalysis and supercapacitor applications.

Size and shape-selective Sn(MoO4)2 nanomaterials have been synthesized for the first time using a simple hydrothermal route by the reaction of Sn(ii) chloride salt with sodium molybdate in CTAB micellar media under stirring at 60 °C temperature for about three hours. Needle-like and flake-like Sn(MoO4)2 nanomaterials were synthesized by optimizing the CTAB to metal salt molar ratio and by controlling other reaction parameters. The eventual diameter and length of the nanoneedles are ∼100 ± 10 nm and ∼850 ± 100 nm respectively.

Unprotected and interconnected Ru nano-chain networks: advantages of unprotected surfaces in catalysis and electrocatalysis.

Seedless, surfactantless and support-free unprotected, metallic, interconnected nano-chain networks of ruthenium nanoparticles (NPs) were successfully synthesized the reduction of ruthenium(iii) chloride (RuCl) with sodium borohydride (NaBH) at three different temperatures, 30 °C, 45 °C and 60 °C. The molar ratio of RuCl solution and borohydride was optimized to be 1 : 1.5 to produce stable colloids with the optimum final solution pH of 9.

Eco-friendly and facile integrated biological-cum-photo assisted electrooxidation process for degradation of textile wastewater.

The present article reports an integrated treatment method viz biodegradation followed by photo-assisted electrooxidation, as a new approach, for the abatement of textile wastewater. In the first stage of the integrated treatment scheme, the chemical oxygen demand (COD) of the real textile effluent was reduced by a biodegradation process using hydrogels of cellulose-degrading Bacillus cereus. The bio-treated effluent was then subjected to the second stage of the integrated scheme viz indirect electrooxidation (InDEO) as well as photo-assisted indirect electro oxidation (P-InDEO) process using Ti/IrO2-RuO2-TiO2 and Ti as electrodes and applying a current density of 20 mA cm(-2).

Synthesis and characterization of DNA fenced, self-assembled SnO2 nano-assemblies for supercapacitor applications.

Self-assembled, aggregated, chain-like SnO2 nano-assemblies were synthesized at room temperature by a simple wet chemical route within an hour in the presence of DNA as a scaffold. The average size of the SnO2 particles and the chain diameter were controlled by tuning the DNA to Sn(ii) molar ratio and altering the other reaction parameters. A formation and growth mechanism of the SnO2 NPs on DNA is discussed.

Electrochemical Determination of Chlorpyrifos on a Nano-TiO₂Cellulose Acetate Composite Modified Glassy Carbon Electrode.

A rapid and simple method of determination of chlorpyrifos is important in environmental monitoring and quality control. Electrochemical methods for the determination of pesticides are fast, sensitive, reproducible, and cost-effective. The key factor in electrochemical methods is the choice of suitable electrode materials.

Bio-molecule assisted aggregation of ZnWO4 nanoparticles (NPs) into chain-like assemblies: material for high performance supercapacitor and as catalyst for benzyl alcohol oxidation.

ZnWO4 nanoparticles (NPs) that are assembled and aggregated together as chain-like morphology have been synthesized via the reaction of Zn(II) salt solution with sodium tungstate in the presence of the DNA scaffold under 5 min of microwave heating. The reaction parameters have been tuned to control the size of the individual particles and diameter of the chains. The significance of different reaction parameters and specific growth mechanism for the formation of particles is elaborated.

DNA-encapsulated chain and wire-like β-MnO2 organosol for oxidative polymerization of pyrrole to polypyrrole.

A DNA-encapsulated chain and wire-like β-MnO2 organosols have been synthesized utilizing a two-phase water-toluene extraction procedure at room temperature (RT). The β-MnO2 organosol was prepared by transferring KMnO4 and DNA from aqueous solution separately to an organic solvent (toluene) using a phase transfer catalyst, mixing both organic solutions together, and subsequent reduction with NaBH4. The eventual diameters of the MnO2 particles in chain-like and wire-like morphologies were ∼1-2 nm and ∼1.

Enhanced catalytic and SERS activities of CTAB stabilized interconnected osmium nanoclusters.

A new route for the formation of osmium nanoparticles (NPs) having different morphologies like aggregated clusters, chain-like networks, and small spheres are reported. The synthesis was done by utilizing a simple wet-chemical method at room temperature (RT) by the reaction of OsO4, cetyl trimethyl ammonium bromide (CTAB), 2,7-dihydroxynaphthalene (2,7-DHN) and NaOH under 30 min of reaction. The diameter of the individual particles in all the morphologies was ∼1-3 nm.

Enhanced catalytic and supercapacitor activities of DNA encapsulated β-MnO₂ nanomaterials.

A new approach is developed for the aqueous phase formation of flake-like and wire-like β-MnO2 nanomaterials on a DNA scaffold at room temperature (RT) within a shorter time scale. The β-MnO2 nanomaterials having a band gap energy ∼3.54 eV are synthesized by the reaction of Mn(II) salt with NaOH in the presence of DNA under continuous stirring.

DNA mediated wire-like clusters of self-assembled TiO₂ nanomaterials: supercapacitor and dye sensitized solar cell applications.

A new route for the formation of wire-like clusters of TiO₂ nanomaterials self-assembled in DNA scaffold within an hour of reaction time is reported. TiO₂ nanomaterials are synthesized by the reaction of titanium-isopropoxide with ethanol and water in the presence of DNA under continuous stirring and heating at 60 °C. The individual size of the TiO₂ NPs self-assembled in DNA and the diameter of the wires can be tuned by controlling the DNA to Ti-salt molar ratios and other reaction parameters.