RETRACTED: Synthesis, Optical and Structural Properties of Copper Sulfide Nanocrystals from Single Molecule Precursors

Abstract

We report the synthesis and structural studies of copper sulfide nanocrystals from copper (II) dithiocarbamate single molecule precursors. The precursors were thermolysed in hexadecylamine (HDA) to prepare HDA-capped CuS nanocrystals. The optical properties of the nanocrystals studied using UV–visible and photoluminescence spectroscopy showed absorption band edges at 287 nm that are blue shifted, and the photoluminescence spectra show emission curves that are red-shifted with respect to the absorption band edges. These shifts are as a result of the small crystallite sizes of the nanoparticles leading to quantum size effects. The structural studies were carried out using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy. The XRD patterns indicates that the CuS nanocrystals are in hexagonal covellite crystalline phases with estimated particles sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes, with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microspheres on the surfaces, and EDS spectra confirmed the presence of CuS nanoparticles.

Avaliação Do Precipitado Obtido Por Biosulfetogênese Da Drenagem Ácida De Mina

“…A presença majoritária de cristais de covellita indicam que a biosulfetogênese foi eficiente na produção do mineral. A presença de agregados com possível forma esférica também poderia ser associada a covellita, pois diferentes morfologias podem ser obtidas como, nanoesferas, nanotubos, nanofios, entre outros, de acordo com a variação (concentração dos reagentes, temperatura, pressão) no processo empregado [18][19][20], além da supersaturação produzir cristais de tamanhos nanométricos [17]. Porém, técnicas de maior acuracidade são necessárias para confirmação desta hipótese.…”

Biomimetic strategies to produce catalytically reactive CuS nanodisks

“…While great advances in synthesizing CuS structures have been achieved to control the plasmon, [12][13][14] band gap, 10,15 and morphology of these materials, 16 these methods generally require unsustainable conditions. [17][18][19][20] In this regard, CuS production typically requires harsh conditions, toxic organic solvents, 21 and/or complex instrumentation that can limit their long-term production. For instance, Chaudhuri and coworkers generated a library of CuS materials of varying shape and composition by using different ratios of chelating and nonchelating solvents in a solvothermal process.…”

RETRACTED: Ajibade, P.A.; Botha, N.L. Synthesis, Optical and Structural Properties of Copper Sulfide Nanocrystals from Single Molecule Precursors. Nanomaterials 2017, 7, 32

“…The Nanomaterials Editorial Office has been made aware that the published paper [1] was previously published in Results in Physics [2] by the same authors. In order to preserve academic integrity, the title paper [1] will be marked as retracted.…”

“…The decision to retract has been taken in agreement with the authors. The manuscript [1] was submitted shortly after the paper had been accepted [2] in Results in Physics , and prior to its publication. The issue resulted from an incorrect version submitted by the authors during the editorial process.…”

“…To ensure the addition of only high-quality scientific works to the field of scholarly publications, reference [1] is retracted and shall be marked accordingly.…”