Publications by authors named "Paul D McNaughter"

A methodology to use laser printing, a form of electrophotography, to print metal chalcogenide complexes on paper, is described. After fusing the toner to paper, a heating step is used to cause the printed metal xanthate complexes to thermolyze within the toner and form three target metal chalcogenides: CuS, SnS, and ZnS. To achieve this, we synthesize a poly(styrene---butyl acrylate) thermopolymer that emulates the thermal properties of a commercial toner and is also solution processable with the metal xanthate complexes used: [Zn(SCOEt)], [Cu(SCOEt)·(PPh)], and [Sn(SCOEt)].

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High-quality Cu(Zn,Fe,Cd)SnS (CZFCTS) thin films based on the parent CZTS were prepared by aerosol-assisted chemical vapor deposition (AACVD). Substitution of Zn by Fe and Cd significantly improved the electrical transport properties, and monophasic CZFCTS thin films exhibited a maximum power factor (PF) of ∼0.22 μW cm K at 575 K.

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Orthorhombic SnS exhibits excellent thermoelectric performance as a consequence its relatively high Seebeck coefficient and low thermal conductivity. In the present work, polycrystalline orthorhombic SnS thin films were prepared by aerosol-assisted chemical vapor deposition (AACVD) using the single source precursor dibutyl-(diethyldithiocarbamato)tin(IV) [Sn(CH)(SCN(CH))]. We examined the effects of the processing parameters on the composition, microstructure, and electrical transport properties of the SnS films.

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Article Synopsis
  • Researchers successfully created the first high-entropy nanoparticles using a mix of lanthanide oxysulfides (Pr, Nd, Gd, Dy, Er) through a thermolysis process.
  • Analysis via powder X-ray diffraction and electron microscopy confirmed the uniformity and distribution of lanthanides within the particles.
  • The nanoparticles exhibited a noticeable blue shift in absorption and photoluminescence spectra compared to bulk samples, which indicates quantum confinement effects, supported by both experimental and theoretical insights into their electronic properties.
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Cadmium sulfide (CdS) is an important semiconductor for electronic and photovoltaic applications, particularly when utilized as a thin film for window layers in CdTe solar cells. Deposition of thin-film CdS through the decomposition of single-source precursors is an attractive approach due to the facile, low-temperature, and rapid nature of this approach. Tailoring the precursor to affect the decomposition properties is commonly employed to tune desirable temperatures of decomposition.

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Facile phase selective synthesis of CuInS (CIS) nanostructures has been an important pursuit because of the opportunity for tunable optical properties of the phases, and in this respect is investigated by hot-injection colloidal synthesis in this study. Relatively monodispersed colloidal quantum dots (3.8-5.

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Manganese(II) xanthate complexes of the form [Mn(SCOR)(TMEDA)], where TMEDA = tetramethylethylenediamine and R = methyl (), ethyl (), -propyl (), -butyl (), -pentyl (), -hexyl (), and -octyl (), have been synthesized and structures elucidated using single-crystal X-ray diffraction. Complexes - were used as molecular precursors to synthesize manganese sulfide (MnS). Olelyamine-capped nanocrystals have been produced hot injection, while the doctor blading followed by thermolysis yielded thick films.

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Four 3d-4f hetero-polymetallic complexes [FeLn((OCH)CR)(OCBu)(HO)] (where Ln = La ( and ) and Gd ( and ); and R = Me ( and ) and Et ( and )) are synthesized and analyzed using elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and SQUID magnetometry. Crystal structures are obtained for both methyl derivatives and show that the complexes are isostructural and adopt a defective dicubane topology. The four heavy metals are connected with two alkoxide bridges.

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Effective electron-hole separation is a key to enhance photoenergy conversion of semiconductor quantum dot (QD)-sensitized plasmonic solar cells. However, in contrast to intense studies on electron transfer, hole transfer from QDs and consequent chemical reactions with donors in electrolytes remain unclear. Herein, in situ electrochemical surface-enhanced Raman scattering (SERS) measurement on a PbS QD-sensitized TiO/Au/TiO photoelectrode indicated formation of -octasulfur (α-S) via tuning the electrochemical potential.

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Alkyl-xanthato gallium(iii) complexes of the form [Ga(SCOR)], where R = Me (1), Et (2), Pr (3), Pr (4), Bu (5), Bu (6) and Bu (7), have been synthesized and fully characterised. The crystal structures for 1 and 3-7 have been solved and examined to elucidate if these structures are related to their decomposition. Thermogravimetric analysis was used to gain insight into the decomposition temperatures for each complex.

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The synthesis of the complete range of (Bi Sb )S solid solutions, where 0 ≤ ≤ 1, by the variation of the mole ratio of bismuth and antimony piperidine dithiocarbamate complexes is reported. There was a near linear expansion of and lattice parameters as the mole ratio of the antimony precursor was increased. The composition of the particles directionally followed the amount of precursor ratio used.

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Selenium and sulfur derivatives of lead(ii) acylchalcogourato complexes have been used to deposit PbSxSe1-x thin films by AACVD. By variation of the mole ratio of sulfur and selenium precursors in the aerosol feed solution the full range of compositions of PbSxSe1-x was obtained, i.e.

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Electromotive force of photovoltaics is a key to define the output power density of photovoltaics. Multiple exciton generation (MEG) exhibited by semiconductor quantum dots (QDs) has great potential to enhance photovoltaic performance owing to the ability to generate more than one electron-hole pairs when absorbing a single photon. However, even in MEG-based photovoltaics, limitation of modifying the electromotive force exists due to the intrinsic electrochemical potential of the conduction band-edges of QDs.

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Black phosphorus is a two-dimensional material that has potential applications in energy storage, high frequency electronics and sensing, yet it suffers from instability in oxygenated and/or aqueous systems. Here we present the use of a polymeric stabilizer which prevents the degradation of nearly 68% of the material in aqueous media over the course of ca. 1 month.

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Article Synopsis
  • The research describes a straightforward method for creating uniform copper sulfide nanocrystals using new copper(I) xanthate precursors through a hot injection process.
  • The study identifies that the width of the nanocrystals varies based on the length of the xanthate chain in the precursors.
  • A computational analysis was conducted to explain the relationship between the energy of the precursor and the resulting width of the copper sulfide rods.
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Transition metal chalcogenides are an important family of materials that have received significant interest in recent years as they have the potential for diverse applications ranging from use in electronics to industrial lubricants. One of their most exciting properties is the ability to generate electricity from incident light. In this perspective we will summarise and highlight the key results and challenges in this area and explain how transition metal chalcogenides are a good choice for future sustainable photovoltaics.

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A series of lead(ii) alkylxanthates, [Pb(SCOR)] (R = ethyl (1), n-propyl (2), n-butyl (3), n-hexyl (4) or n-octyl (5)) have been prepared and explored as single source precursors for use in melt reactions to form lead sulfide. X-ray single crystal structures of (2), (3) and (4) were used along with previously reported structures to investigate the influence of structure and chain length on the materials produced. The complexes were decomposed at 150, 175 or 200 °C forming PbS nanocrystals as confirmed by XRD and TEM.

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We report the electrochemical detection of the redox active cardiac biomarker myoglobin (Mb) using aptamer-functionalized black phosphorus nanostructured electrodes by measuring direct electron transfer. The as-synthesized few-layer black phosphorus nanosheets have been functionalized with poly-l-lysine (PLL) to facilitate binding with generated anti-Mb DNA aptamers on nanostructured electrodes. This aptasensor platform has a record-low detection limit (∼0.

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An orally-administered vehicle for targeted, on-demand drug delivery to the gastrointestinal (GI) tract is highly desirable due to the high incidence of diseases of that organ system and harsh mechanical and physical conditions any such drug delivery vehicle has to endure. To that end, we present an iron oxide nanoparticle/wax composite capsule coating that protects the capsule contents from the highly variable chemical conditions of the GI tract. It can be triggered using magnetic hyperthermia initiated from an external AC magnetic field.

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An orally-administered system for targeted, on-demand drug delivery to the gastrointestinal (GI) tract is highly desirable due to the high instances of diseases of that organ system and harsh mechanical and physical conditions any such system has to endure. To that end, we present an iron oxide nanoparticle/wax composite capsule coating using magnetic hyperthermia as a release trigger. The coating is synthesised using a simple dip-coating process from pharmaceutically approved materials using a gelatin drug capsule as a template.

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Bi-phasic or multi-phasic composite nanoparticles for use in photocatalysis have been produced by a new synthetic approach. Sol-gel methods are used to deposit multiple layers of active material onto soluble substrates. In this work, a layer of rutile (TiO2) was deposited onto sodium chloride pellets followed by an annealing step and a layer of anatase.

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Composites of sulphur polymers with nanoparticles such as PbS, with tunable optical properties are reported. A hydrothermal route incorporating pre-formed nanoparticles was used, and their physical and chemical properties evaluated by transmission and scanning electron microscopy, thermogravimetric and elemental analyses. These polymers are easily synthesised from an industrial waste material, elemental sulphur, can be cast into virtually any form and as such represent a new class of materials designed for a responsible energy future.

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The synthesis of iron oxide nanocrystals from reagents taken from high street sources using thermal decomposition of an iron-fatty acid precursor in a high boiling point solvent in the presence of surfactants is presented. The nanocrystals were characterised using a variety of techniques including: electron microscopy, X-ray dispersive spectroscopy, infrared spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and magnetometry. Thermogravimetric analysis (TGA) is also used to compare the decomposition behaviour of iron oleate and iron palmitate, our nanoparticle precursors.

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The first photoactivated doped quantum dot vector for metal-ion release has been developed. A facile method for doping copper(I) cations within ZnS quantum dot shells was achieved through the use of metal-dithiocarbamates, with Cu(+) ions elucidated by X-ray photoelectron spectroscopy. Photoexcitation of the quantum dots has been shown to release Cu(+) ions, which was employed as an effective catalyst for the Huisgen [3+2] cycloaddition reaction.

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Herein, we report the synthesis of three covalently linked superparamagnetic nanocrystal-multi-walled carbon nanotube (MWCNT) composites. A generic strategy for amphiphilic polymer coating of nanocrystals and further functionalization for amide bond formation with the MWCNTs is discussed. This approach can in principle allow attachment of any colloidal nanocrystal to the MWCNTs.

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