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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFCovalent 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.
View Article and Find Full Text PDFElectrochemical 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.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFIn 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.
View Article and Find Full Text PDFElectrocatalytic 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.
View Article and Find Full Text PDFElectrodics 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.
View Article and Find Full Text PDFBand 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.
View Article and Find Full Text PDFStable 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).
View Article and Find Full Text PDFNanoparticles 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.
View Article and Find Full Text PDFReversible 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.
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