Publications by authors named "Vincent O Nyamori"

In the title compound, CHNO, the N atoms of the pyridine rings exhibit a typical - arrangement: the dihedral angles between the central pyridine ring and the peripheral rings are 22.24 (4) and 2.38 (4)°.

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The practical utilization of TiO as a semiconductor in dye-sensitized solar cells (DSSCs) has been set back by poor visible light absorption, high charge carrier recombination, and low electrical conductivity, which reduce the power conversion efficiency (PCE) and sustainability of the device. In this respect, perovskites with excellent properties, such as large surface area, good optical properties, high electrical conductivity, and superior electrochemical stability, have recently emerged as promising alternatives capable of overcoming the drawbacks of TiO. Herein, SrSmFeCoO (SSFC) perovskites were prepared via the ball milling method at various milling times of 0, 5, and 10 h, and the obtained samples were denoted by SSFC-0, SSCF-5, and SSCF-10, respectively.

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Due to the finite nature, health and environmental hazards currently associated with the use of fossil energy resources, there is a global drive to hasten the development and deployment of renewable energy technologies. One such area encompasses perovskite solar cells (PSCs) that have shown photoconversion efficiencies (PCE) comparable to silicon-based photovoltaics, but their commercialisation has been set back by short-term stability and toxicity issues, among others. A tremendous potential to overcome these drawbacks is presented by the emerging applications of graphene derivative-based materials in PSCs as substitutes or components, composites with other functional materials, and enhancers of charge transport, blocking action, exciton dissociation, substrate coverage, sensitisation and stabilisation.

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Semiconductor materials have been recently employed in photovoltaic devices, particularly dye-sensitized solar cells (DSSCs), to solve numerous global issues, especially the current energy crisis emanating from the depletion and hazardous nature of conventional energy sources, such as fossil fuels and nuclear energy. However, progress for the past years has been mainly limited by poor electron injection and charge carrier recombination experienced by DSSCs at the photoanode. Thus, novel semiconductor materials such as bismuth oxide (BiO) have been investigated as an alternative photoanode material.

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In recent years, carbon-based materials, particularly carbon nanotubes (CNTs), have gained intensive research attention in the fabrication of organic solar cells (OSCs) due to their outstanding physicochemical properties, low-cost, environmental friendliness and the natural abundance of carbon. In this regard, the low sheet resistance and high optical transmittance of CNTs enables their application as alternative anodes to the widely used indium tin oxide (ITO), which is toxic, expensive and scarce. Also, the synergy between the large specific surface area and high electrical conductivity of CNTs provides both large donor-acceptor interfaces and conductive interpenetrating networks for exciton dissociation and charge carrier transport.

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Parasitic diseases remain a major public health concern for humans, claiming millions of lives annually. Although different treatments are required for these diseases, drug usage is limited due to the development of resistance and toxicity, which necessitate alternative therapies. It has been shown in the literature that parasitic lactate dehydrogenases (LDH) and malate dehydrogenases (MDH) have unique pharmacological selective and specificity properties compared to other isoforms, thus highlighting them as viable therapeutic targets involved in aerobic and anaerobic glycolytic pathways.

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Presently, artemisinin-based combination therapy (ACT) is the first-line therapy of Plasmodium falciparum malaria. With the emergence of malaria parasites that are resistant to ACT, alternative antimalarial therapies are urgently needed. In line with this, we designed and synthesised a series of novel N-(7-chloroquinolin-4-yl)-N'-(4,6-diphenylpyrimidin-2-yl)alkanediamine hybrids (6a-7c) and evaluated their inhibitory activity against the NF54 chloroquine-susceptible strain as a promising class of antimalarial compounds.

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Introduction: The aggressive search for renewable energy resources and essential pyrosynthetic compounds has marked an exponential rise in the thermal degradation of biomass materials. Consequently, clean and sustainable transport fuels are increasingly desirable in a highly industrialized economy, for energy security and environmental protection. For this reason, biomass materials have been identified as promising alternatives to fossil fuels despite the challenges resulting from the possible formation of toxic nitrogen-based molecules during biomass degradation.

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In the past few years, dye-sensitized solar cells (DSSCs) have received considerable research attention, as potential alternatives to the commonly used, but expensive, silicon-based solar cells owing to the low-cost, facile fabrication procedures, less impact on the environment, capability of working even under low incoming light levels, and flexibility of DSSCs. However, the relatively low power conversion efficiencies (PCEs) and poor long-term operational stability of DSSCs still limit their large-scale and commercial applications. As a consequence, this has prompted tremendous research effort towards the realization of high performance and sustainable devices, through tailoring of the properties of the various DSSC components, approaches such as introducing novel materials and new synthesis techniques.

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Considering its availability, renewable character and abundance in nature, this review assesses the opportunity of the application of biomass as a precursor for the production of carbon-based nanostructured materials (CNMs). CNMs are exceptionally shaped nanomaterials that possess distinctive properties, with far-reaching applicability in a number of areas, including the fabrication of sustainable and efficient energy harnessing, conversion and storage devices. This review describes CNM synthesis, properties and modification, focusing on reports using biomass as starting material.

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Diverse P,N-phosphine ligands reported to date have performed exceptionally well as auxiliary ligands in organometallic catalysis. Phosphines bearing 2-pyridyl moieties prominently feature in literature as compared to phosphines with five-membered N-heterocycles. This discussion seeks to paint a broad picture and consolidate different synthetic protocols and techniques for N-heterocyclic phosphine motifs.

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Six ferrocenyl imidazole derivatives substituted with -Cl, -NO and -CH on the 2-position of the 1H-imidazole ring have been synthesized. Of the six compounds, the di-substituted ferrocenes, i.e.

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The greatest challenge in graphene-based material synthesis is achieving large surface area of high conductivity. Thus, tuning physico-electrochemical properties of these materials is of paramount importance. An even greater problem is to obtain a desired dopant configuration which allows control over device sensitivity and enhanced reproducibility.

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Background: The atmosphere has become a major transport corridor for free radicals and particulate matter from combustion events. The motivation behind this study was to determine the nature of particulate emissions and surface bound radicals formed during the thermal degradation of diesel blends in order to assess the health and environmental hazards of binary transport fuels.

Methodology: Accordingly, this contribution explored the interactions that occur when Croton megalocarpus biodiesel and fossil diesel in the ratio of 1:1 by weight were co-pyrolyzed in a quartz reactor at a residence time of 0.

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Pyrolysis of biodiesel at high temperatures may result in the formation of transient and stable free radicals immobilized on particulate emissions. Consequently, free radicals adsorbed on particulates are believed to be precursors for health-related illnesses such as cancer, cardiac arrest, and oxidative stress. This study explores the nature of free radicals and particulate emissions generated when Croton megalocarpus biodiesel is pyrolyzed at 600 °C in an inert environment of flowing nitrogen at a residence time of 0.

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This study presents the successful synthesis of a novel nanocomposite, namely a germanium quantum dot/nitrogen-doped graphene nanocomposite (GeQD/NGr), and its use in the modification of the photoactive medium of bulk heterojunction solar cells (BHJ-SCs). The nanocomposite was prepared in two sequential steps. Firstly, a reduced graphene oxide-germanium oxide nanocomposite (rGO-GeO) was synthesized by microwave-assisted solvothermal reaction.

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Graphene provides numerous possibilities for structural modification and functionalization of its carbon backbone. Localized magnetic moments can, as well, be induced in graphene by the formation of structural defects which include vacancies, edges, and adatoms. In this work, graphene was functionalized using germanium atoms, we report the effect of the Ge ad atoms on the structural, electrical, optical and magnetic properties of graphene.

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A series of three-dimensional (3D) porous nanocomposites, comprised of partially reduced graphene oxide (pRGO) and CO containing Mg-Al layered double hydroxide, were synthesized in two steps. In the first step, graphene oxide (GO) was fabricated by a modified Hummers' method, and, subsequently, in the second step layered double hydroxide (LDH) nanosheets were homogeneously grown on the surface of the GO sheets by an in situ crystallization approach, involving a facile coprecipitation technique. The alkaline medium used for the in situ growth of LDH on the GO surface resulted in the partial reduction of GO to pRGO, which was confirmed by XRD.

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The need for green synthesis of emerging industrial materials has led to the biosynthesis of nanoparticles from plants to circumvent the adverse by-products of chemical synthesis. In this study, the leaf extract of Detarium mirocarpum Guill & Perr, a small tree belonging to the family Fabaceae (Legume), was used to synthesize silver nanoparticles (DAgNPs). DAgNPs were characterized using spectroscopic techniques (Ultraviolet-Visible spectroscopy and Fourier Transform Infrared spectroscopy) which showed hydroxyl and carbonyl functional groups to be responsible for their synthesis.

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Imidazolium trans-[tetrachloridodimethylsulfoxideimidazoleruthenate(III)], NAMI-A, is a promising antimetastatic prodrug with high specificity for metastatic cancer cells. Limited activity of NAMI-A against primary tumor suggests that its use in combination with other anticancer drug(s) might present a more desirable therapeutic outcome. The mechanism of activation and action of this prodrug is still largely unknown.

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The asymetric unit of the title compound, [Fe(C5H5)(C17H13N2)], contains two independent mol-ecules whose conformations differ, especially in the 4-{(pyridin-4-yl)methyl-idene]amino}-phenyl unit where one is flipped by almost 180°. The cyclo-penta-dienyl rings of the ferrocene unit also exhibit different staggered conformations: in one mol-ecule the conformation is staggered by 9.43 (2)° and in the other by 24.

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The structure of the title compound, [Fe(C5H5)(C10H12N2)]I, consists of a 1-(ferrocen-1-ylmeth-yl)-3-methyl-imidazolium cation which is counter-balanced by an iodide anion. The cyclo-penta-dienyl (Cp) rings of the ferrocene unit have a slightly staggered conformation skewed from an ideal eclipsed conformation by an angle of 3.5 (6)°.

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The crystal structure of the title compound, [Fe(C(5)H(5))(C(10)H(12)N(2))]PF(6), consists of a ferrocene-1-methyl-(3-methyl-imidazolium) cation and a hexa-fluorido-phosphate anion. The ferrocenyl rings are skewed by 6.7 (4)° from the ideal eclipsed conformation.

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The crystal structure of the title salt, C(44)H(38)P(2) (2+)2BF(4) (-), consists of discrete dications inter-laced with the BF(4) (-) counter-ions. In each cation, both phospho-nium groups lie on the same side of the plane of the central benzene ring. The tetra-fluoro-borate anions are involved in intensive thermal motion, thus some B-F bond lengths [range 1.

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3-Ferrocenyl-2-(4-nitro-phen-yl)acrylonitrile.

Acta Crystallogr Sect E Struct Rep Online

September 2011

In the title compound, [Fe(C(5)H(5))(C(14)H(9)N(2)O(2))], the ferrocenyl rings exhibit an eclipsed conformation with a staggering angle of 15.9°, which is quite large compared to similar compounds.

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