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- Heterocyclic dithiocarbamate complex of manganese and the adducts of the complex with 1,10-phenanthroline and 2,2-bipyridyl respectively were synthesized and characterized. The complexes were used as single-source precursors for the preparation of MnS nanoparticles via thermolysis in oleylamine (OLA) and dodecanethiol (DT). The optimized reaction parameters have resulted in the formation of α-MnS and γ-MnS nanoparticles depending on the dispersion medium and the nature of the precursor. The same precursors were also used for the deposition of MnS thin films by the aerosol-assisted chemical vapour deposition (AACVD) method in varying solvents and temperatures. The morphology and phase of the synthesized nanoparticles were shown to be affected by the precursor type and the nature of the surfactants. TEM images show the formation of nanoparticles of various morphologies ranging from spherical monodispersed to large elongated pointed rods, depending on the precursor type. SEM images showed that the morphology of the deposited thin films is affected by precursor type and the deposition temperature. Worm-like to rod-like films were observed on TEM images at 350 ◦C, which changes to spherical or cubic films at 450 ◦C. Magnetic measurements at room temperature showed the α-MnS and γ-MnS nanoparticles in paramagnetic states due to Mn2+moments. The susceptibility for the γ-phase is at least double that of the α-phase. Finite and small hysteretic effects in low fields are indicative of small ordered antiferromagnetic phases due to negative exchange interaction between Mn2+ions.
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- Copper sulfide thin films and nanoparticles have been prepared via aerosol assisted chemical vapour deposition and solvothermal hot injection routes, respectively. Both routes employed heterocyclic amine based benzoylthioureato-copper(II) complexes as single source precursors. Copper sulfide thin films of diverse morphologies ranging from cubic to snowy or irregular crystallites depending on the deposition temperature were observed. Powder X-ray diffraction studies of the as deposited thin films have indicated the formation of hexagonal and cubic phases of copper sulfide. In the case of the nanoparticles, Roxbyite (Cu1.75S) phase was obtained in dodecanethiol at temperatures of 150, 190 and 230 °C. However, a preferred growth of nanoparticles was observed in the presence of oleylamine whereas the roxbyite phase was obtained at temperatures of 150, 200 and 250 °C. Also transmission electron microscopy showed the formation of close to spherical, hexagonal nano-disk and rod shaped nanoparticles.
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- 2025| Springer NatureMn2+-, Ni2+-, and Co3+-doped pyrrhotite nanoparticles were synthesized via the hot injection thermolysis method. The optical and structural properties of the pure and doped pyrrhotite nanoparticles were studied using UV–visible spectroscopy. Powder X-ray diffractometry (p-XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the particles. p-XRD studies showed that doping had no effect on the basic structure of the nanoparticles. The doped nanoparticles showed the formation of single-phase monoclinic type pyrrhotite (Fe1-xS) structure. UV–visible spectroscopy revealed that the incorporation of Ni2+, Fe3+, and Co3+ ions as dopants decreases the energy bandgap of the pyrrhotite nanoparticles. TEM images showed an increase in nanoparticle sizes with the incorporation of dopants. Both elemental mapping and EDX analysis of the doped nanoparticles reveal the presence of Mn2+, Ni2+, and Co3+ doping ions in the pyrrhotite lattice.
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- 2021| Scientific and Techn...Cadmium dithiocarbamate and cadmium ethyl xanthate complexes were synthesized and characterized by microanalysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses. The complexes were employed as molecular precursors for the fabrication of CdS nanoparticles in hexadecylamine (HDA) and oleylamine (OLA) at a temperature of 250 C. Spherical and oval shaped particles with sizes ranging from 9.93±1.89 to 16.74±2.78 nm were obtained in OLA while spherical, oval and rod shaped particles with sizes ranging from 9.40±1.65 to 29.90±5.32 nm were obtained in HDA. Optical properties of the nanoparticles showed blue shifts as compared to the bulk CdS, with the OLA capped nanoparticles slightly more blue shifted than the corresponding HDA capped nanoparticles. Results of crystallinity patterns revealed hexagonal phase of CdS.
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- A series of Fe(III), Co(III), Ni(II), Cu(II), Zn(II) and In(III) N-morpholine-N'-benzoyl thiourea complexes have been synthesized and characterized by elemental analysis, thermal analysis, infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy and single-crystal X-ray crystallography. Thermogravimetric analysis shows that all the complexes undergo a two-step decomposition process except for the iron(III) complex and the indium(III) complexes, which show three-step and one-step decompositions, respectively. The complexes are thermally stable up to approximately 300°C. The ligand coordinates the various metal ions in a bidentate (L-kO,S) chelating mode, facilitated by deprotonation of the acidic amide (–C(O) N'HC (S)) moiety. This mode of coordination allows for the facile formation of neutral bis/tris-6-membered chelates of type [M(L-kS,O)x] where x = 2 or 3 for divalent or trivalent metal ions, respectively.
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- Increasing demand for sustainable energy has boosted the exploration of inexpensive and efficient catalysts. Transition metal sulfides have been proven as efficient electrocatalysts for energy storage or energy generation applications. Herein, cubic phase α-MnS and transition metal (Cu2+, Fe3+, and Ni2+) doped MnS nanoparticles were synthesized via the hot injection method from their piperazinyl dithiocarbamate complexes, respectively. The morphology of pristine and TM-doped MnS nanoparticles was studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis, while optical and structural properties were studied using UV–visible spectroscopy and powder X-ray diffraction (p-XRD), respectively. p-XRD analysis confirmed the successful incorporation of dopants into MnS lattice structure and suitability of heterocyclic dithiocarbamate complexes for phase/composition controlled synthesis of nanomaterials. The effect of doping on electrocatalytic properties was also investigated. The MnS-based electrodes doped with Ni and Fe presented satisfactory specific capacitances of 840 and 900 F/g at 2 mV/s scan rate. In addition, the testing for electrocatalysis for the water-splitting process demonstrated that Ni–MnS had a superior performance for HER with a η of 132 mV at 10 mA/cm2 and Tafel slope of 44 mV/dec. On the other hand, Fe–MnS showed better performance towards OER with a η of 280 mV at 10 mA/cm2 and a Tafel slope of 60 mV/dec.
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