Novel Metal Xanthate Precursors for Nanostructured Metal Sulfides

  • Mousa Hossin

Student thesis: Phd


During the last years, semiconducting materials especially transition metal sulfides have received significant attention due to their numerous applications such as in solar cells, electronic, optoelectronic, and thermoelectric devices. Therefore, materials researchers and chemists have been extensively exploring new manufacturing processes to generate high-quality, low-cost, time and energy saving nanomaterials. Various synthetic methods have been proposed for the fabrication of metal sulfide nanoparticles, but the single source precursors (SSPs) approach is usually favorable due to their suitability for the preparation of nano-dimensional materials and the possibility of a better control over phase composition. In this thesis, xanthate complexes of three main elements from row six in the Periodic Table including barium(II), lead(II) and bismuth(III) were synthesised and characterised. Theses complexes were utilized as molecular precursors for the formulation of binary and ternary metal sulfide nanoparticles. This work displays the synthesis of twelve alkylxanthatobismuth(III) complexes of the general formula of [Bi(S2COR)3] where R= Me, Et, nPr, iPr, nBu, sBu, iBu, nPent, iPent, nHex, nHept and nOct and their thermal decomposition and spectroscopic characterisation. Some of these compounds were applied as suitable SSPs for the synthesis of bismuth sulfide (Bi2S3) by solventless pyrolysis at 175 °C under nitrogen. Bi2S3 nanocrystals were studied in detail by using powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM) and Raman spectroscopy. Preferred crystallite orientation growth of Bi2S3 in the peak intensity of (021) plane is observed, when longer hydrocarbon chain complexes were used as SSPs. This thesis then describes the preparation of a series of Bi2S3-PbS alloys in the range of (0 ≤ x ≤ 1) via a solventless pyrolysis at 400 °C under nitrogen atmosphere using carefully selected tris(npropylxanthato)bismuth(III) and bis(npropylxanthato)lead(II) as molecular precursors. Then, the powder samples obtained from both complexes were studied employing several advanced characterisation methods to explore the impact of dopants on the morphological, stoichiometry and general structural features of the host material. Finally, a new range of novel bis(O-alkylxanthato)barium(II) complexes with different linear chain alkyl groups has been synthesised and their spectroscopic properties and crystal structures were measured, and used as SSPs for the formation of barium sulfide (BaS) at different temperatures ranging from 250 °C to 500 °C under inert conditions by a solid state deposition method. Characterisation of the final materials was accomplished by using p-XRD and SEM.
Date of Award31 Dec 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorDavid Collison (Supervisor) & David Lewis (Supervisor)


  • Bismuth sulfide
  • single-source precursor
  • Lead sulfide
  • Single molecular precursors
  • Barium sulfide
  • Semiconductor
  • Metal Sulfide
  • Xanthate
  • Nanomaterials

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