Composition-dependent band structure parameters and band-gap bowing effect in a caesium lead mixed halide system: a cyclic voltammetry investigation.

Cyclic voltammetry techniques have been employed to study the effect of halide substitution on the band edge parameters and band gap bowing effect in the case of CsPbX [X = I, Br, Cl] perovskite nanocrystals (PNCs). A series of compositions, CsPbI, CsPb(I-Br), CsPbBr, CsPb(Br-Cl) and CsPbCl, have been prepared by a hot injection method. From powder XRD and HR-TEM analysis, the formation of a highly crystalline, cubic phase of the perovskite having size in the range from 7-20 nm has been confirmed.

Siderophore mediated mineralization of struvite: A novel greener route of sustainable phosphate management.

Efficient and sustainable removal of phosphate ions from an aqueous solution is of great challenge. Herein we demonstrated a greener route for phosphate recovery through struvite formation by using bacterial siderophore. This method was efficient for removal of phosphate as low as 1.

γ-Ray-Assisted Synthesis of a Pt-Sn Composite Loaded on Graphene-Graphitic Carbon Nitride Hybrid: A Cocktail Electrocatalyst for the Methanol Oxidation Reaction.

The composite of Pt with transition metals is viewed as the most promising anode material for direct methanol fuel cell (DMFC) applications. Besides the decrease in the Pt loading, these multimetallic structures help in circumventing CO poisoning issues associated with a Pt catalyst. Herein, we prepared and loaded Pt-Sn bimetallic nanoparticles on an electron-rich and stable substrate consisting of graphitic nitride (GCN) and graphene oxide (GO)/reduced graphene oxide (r-GO) hybrid composites.

Covalent conjugation of single-walled carbon nanotube with CYP101 mutant for direct electrocatalysis.

Covalent linkage between the single-walled carbon nanotube (SWCNT) and CYP101 through a specific site of the enzyme can provide a novel method of designing efficient enzyme electrodes using this prototype cytochrome P450 enzyme. We have chemically modified the SWCNT with linker 4-carboxy phenyl maleimide (CPMI) containing maleimide functional groups. The enzyme was covalently attached on to the SWCNT through the maleimide group of the linker (CPMI) to the thiolate group of the surface exposed Cys 58 or Cys 136 of the CYP101 forming a covalently immobilized protein on the nanotube.

Experimental and Theoretical Study into Interface Structure and Band Alignment of the CuZn Cd SnS Heterointerface for Photovoltaic Applications.

To improve the constraints of kesterite CuZnSnS (CZTS) solar cell, such as undesirable band alignment at p-n interfaces, bandgap tuning, and fast carrier recombination, cadmium (Cd) is introduced into CZTS nanocrystals forming CuZn Cd SnS through cost-effective solution-based method without postannealing or sulfurization treatments. A synergetic experimental-theoretical approach was employed to characterize and assess the optoelectronic properties of CuZn Cd SnS materials. Tunable direct band gap energy ranging from 1.

High sensitive determination of dopamine through catalytic oxidation and preconcentration over gold-multiwall carbon nanotubes composite modified electrode.

Electrochemical properties of dopamine, uric acid and ascorbic acid have been investigated using gold nano particles (AuNPs) decorated functionalized multiwall carbon nanotubes (MWCNTs) nano composite modified electrode. MWCNTs were acid functionalized to introduce -COOH functionalities. The functionalized MWCNTs were used as support materials and were decorated with gold nano particles of 20 nm in size.

Point contact Andreev reflection studies of a non-centro symmetric superconductor ReZr.

ReZr, a non-centrosymmetric superconductor is an interesting system as recent experimental evidence suggests that the superconducting state breaks time reversal symmetry. This implies a mixing of spin singlet-triplet states leading to a complex order parameter in this system. Here, we report point contact Andreev Reflection (PCAR) measurements on a single crystal of ReZr (superconducting transition temperature (T) = 6.

Coupling Energy Capture and Storage - Endeavoring to make a solar battery.

Storage of solar radiation is currently accomplished by coupling two separate devices, one that captures and converts the energy into an electrical impulse (a photovoltaic cell) and another that stores this electrical output (a battery or a supercapacitor electrochemical cell). This configuration however has several challenges that stem from a complex coupled-device architecture and multiple interfaces through which charge transfer has to occur. As such presented here is a scheme whereby solar energy capture and storage have been coupled using a single bi-functional material.

Boosting the Efficiency of Quantum Dot-Sensitized Solar Cells through Formation of the Cation-Exchanged Hole Transporting Layer.

In search of a viable way to enhance the power conversion efficiency (PCE) of quantum dot-sensitized solar cells, we have designed a method by introducing a hole transporting layer (HTL) of p-type CuS through partial cation exchange process in a postsynthetic ligand-assisted assembly of nanocrystals (NCs). High-quality CdSe and CdSSe gradient alloy NCs were synthesized through colloidal method, and the charge carrier dynamics was monitored through ultrafast transient absorption measurements. A notable increase in the short-circuit current concomitant with the increase in open-circuit voltage and the fill factor led to 45% increment in PCE for CdSe-based solar cells upon formation of the CuS HTL.

A novel inhibition based biosensor using urease nanoconjugate entrapped biocomposite membrane for potentiometric glyphosate detection.

A potentiometric biosensor based on agarose-guar gum (A-G) entrapped bio-nanoconjugate of urease with gold nanoparticles (AUNps), has been reported for the first time for glyphosate detection. The biosensor is based on inhibition of urease activity by glyphosate, which was measured by direct potentiometry using ammonium ion selective electrode covered with A-G-urease nanoconjugate membrane. TEM and FTIR analysis revealed nanoconjugate formation and its immobilization in A-G matrix respectively.

Nanostructured MoS/BiVO Composites for Energy Storage Applications.

We report the optimized synthesis and electrochemical characterization of a composite of few-layered nanostructured MoS along with an electroactive metal oxide BiVO. In comparison to pristine BiVO, and a composite of graphene/BiVO, the MoS/BiVO nanocomposite provides impressive values of charge storage with longer discharge times and improved cycling stability. Specific capacitance values of 610 Fg (170 mAhg) at 1 Ag and 166 Fg (46 mAhg) at 10 Ag were obtained for just 2.

CZTS x Se1-x nanocrystals: Composition dependent method of preparation, morphological characterization and cyclic voltammetry data analysis.

In this article, synthesis procedures of preparation of copper zinc tin sulpho-selenide (CZTS x Se1-x ) alloy nanocrystals and the data acquired for the material characterization are presented. This data article is related to the research article doi: http://dx.doi.

Electrocatalyst on insulating support?: Hollow silica spheres loaded with Pt nanoparticles for methanol oxidation.

Electrocatalytic oxidation of methanol on silica hollow spheres, loaded with platinum nanoparticles (Pt-SiO2-HS), is reported. The functionalized hollow silica spheres were prepared by the surfactant (lauryl ester of tyrosine) template-assisted synthesis. These spheres were loaded with platinum nanoparticles by γ-radiolysis.

A facile methodology for the design of functionalized hollow silica spheres.

A new amino acid derived amphiphile, lauryl ester of tyrosine (LET) is shown to provide a facile methodology for the preparation of hollow silica spheres. In a previous study on the interface adsorption, it was shown that phenolic OH group in LET plays a key role in the formation and stabilization of close packed structures, typically at the oil/water interface. Drawing an analogy between the air/water and the oil/water interface, we detail here a procedure where air droplets are capped with LET aggregated structures, and in turn they are utilized as viable templates in the production of hollow silica spheres.

Outer sphere electroreduction of CCl4 in 1-butyl-3-methylimmidazolium tetrafluoroborate: an example of solvent specific effect of ionic liquid.

Electrodics of CCl4 reduction in 1-butyl-3-methylimmidazolium tetrafluoroborate [BMIM][BF4] room temperature ionic liquid (RTIL) is reported. A convolutive analysis of the cyclic voltammograms suggests that CCl4 electroreduction follows stepwise (outer sphere) dissociative electron transfer pathway, rather than the sticky dissociative (inner sphere) electron transfer, as in the case of conventional organic solvents. This difference in the mechanism of electron transfer initiated bond cleavage is attributed to the solvent specific effects, namely, stabilization of CCl4*- intermediate radical anion in RTIL, which in turn decreases the electron transfer rate and thus the carbon-halogen bond cleavage rates.

Determination of band structure parameters and the quasi-particle gap of CdSe quantum dots by cyclic voltammetry.

Band structure parameters such as the conduction band edge, the valence band edge and the quasi-particle gap of diffusing CdSe quantum dots (Q-dots) of various sizes were determined using cyclic voltammetry. These parameters are strongly dependent on the size of the Q-dots. The results obtained from voltammetric measurements are compared to spectroscopic and theoretical data.

Electrochemical biosensor for catechol using agarose-guar gum entrapped tyrosinase.

An electrochemical biosensor using tyrosinase was constructed for the determination of catechol. The enzyme was extracted from a plant source Amorphophallus companulatus and entrapped in agarose-guar gum composite biopolymer matrix. Catechol was determined by direct reduction of biocatalytically liberated quinone species at -0.

Synthesis and characterization of stable organosols of silver nanoparticles by electrochemical dissolution of silver in DMSO.

Stable organosols of silver nanoparticles (AgNPs) without any capping agents have been synthesized by an electrochemical dissolution of a sacrificing silver electrode in dimethyl sulfoxide (DMSO). The peak at 425 +/- 5 nm observed in the UV-vis spectra was attributed to the surface plasmon resonance for silver. The formation of nanoparticles of silver was confirmed by X-ray diffraction analysis (XRD).

Synthesis and characterization of uncapped gamma-Fe2O3 nanoparticles prepared by flame pyrolysis of ferrocene in ethanol.

Nanoparticles of iron(III) oxide were synthesized by spontaneous combustion of ferrocene in ethanol solution using a simple spirit lamp. X-ray powder diffraction and electron diffraction analysis of the powder suggested the formation of gamma-Fe2O3 (Maghemite phase) having lattice constant 8.3539 +/- 0.

Development of electrochemical biosensor based on tyrosinase immobilized in composite biopolymeric film.

An electrochemical enzyme electrode for dopa and dopamine was developed via an easy and effective immobilization method. The enzyme tyrosinase was extracted from a plant source Amorphophallus companulatus and immobilized in a novel composite of two biopolymers: agarose and guar gum. This composite matrix-containing enzyme forms a self-adhering layer on the active surface of glassy carbon electrode, making it a selective and sensitive phenol sensor.

Electrochemistry and electrogenerated chemiluminescence from silicon nanocrystal quantum dots.

Reversible electrochemical injection of discrete numbers of electrons into sterically stabilized silicon nanocrystals (NCs) (approximately 2 to 4 nanometers in diameter) was observed by differential pulse voltammetry (DPV) in N,N'-dimethylformamide and acetonitrile. The electrochemical gap between the onset of electron injection and hole injection-related to the highest occupied and lowest unoccupied molecular orbitals-grew with decreasing nanocrystal size, and the DPV peak potentials above the onset for electron injection roughly correspond to expected Coulomb blockade or quantized double-layer charging energies. Electron transfer reactions between positively and negatively charged nanocrystals (or between charged nanocrystals and molecular redox-active coreactants) occurred that led to electron and hole annihilation, producing visible light.