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Lithium intercalation compounds, such as the complex metal oxide, lithium nickel manganese cobalt oxide (LiNi x Mn y Co 1−x−y O 2 , herein referred to as NMC), have demonstrated their utility as energy storage materials. In response to recent concerns about the global supply of cobalt, industrially synthesized NMCs are shifting toward using NMC compositions with enriched nickel content. However, nickel is one of the more toxic components of NMC materials, meriting investigation of the toxicity of these materials on environmentally relevant organisms. Herein, the toxicity of both nanoscale and microscale Ni-enriched NMCs to the bacterium, Shewanella oneidensis MR-1, and the zooplankton, Daphnia magna , was assessed. Unexpectedly, for the bacteria, all NMC materials exhibited similar toxicity when used at equal surface area-based doses, despite the different nickel content in each. Material dissolution to toxic species, namely nickel and cobalt ions, was therefore modelled using a combined density functional theory and thermodynamics approach, which showed an increase in material stability due to the Ni-enriched material containing nickel with an oxidation state >2. The increased stability of this material means that similar dissolution is expected between Ni-enriched NMC and equistoichiometric NMC, which is what was found in experiments. For S. oneidensis , the toxicity of the released ions recapitulated toxicity of NMC nanoparticles. For D. magna , nickel enrichment increased the observed toxicity of NMC, but this toxicity was not due to ion release. Association of the NMC was observed with both S. oneidensis and D. magna. This work demonstrates that for organisms where the major mode of toxicity is based on ion release, including more nickel in NMC does not impact toxicity due to increased particle stability; however, for organisms where the core composition dictates the toxicity, including more nickel in the redesign strategy may lead to greater toxicity due to nanoparticle-specific impacts on the organism.
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MnO, Co and Ni Nanoparticle Synthesis by Oleylamie and Oleic Acid
Background: Magnetic nanoparticles are attracting much attention toward easyoperation and size controllable synthesis methods. We develop a method to synthesize MnO, Co,CoO, and Ni nanoparticles by thermal decomposition of metal 2,4-pentanedionates in the presenceof oleylamine (OLA), oleic acid (OA), and 1-octadecene (ODE). Methods: Similar experimental conditions are used to prepare nanoparticles except for the metalstarting materials (manganese 2,4-pentanedionate, nickel 2,4-pentanedionate, and cobalt 2,4-pentanedionate), leading to different products. For the manganese 2,4-pentanedionate startingmaterial, MnO nanoparticles are always obtained as the reaction is controlled with differenttemperatures, precursor concentrations, ligand ratios, and reaction time. For the cobalt 2,4-pentanedionate starting material, only three experimental conditions can produce pure phase CoOand Co nanoparticles. For the nickel 2,4-pentanedionate starting material, only three experimentalconditions lead to the production of pure phase Ni nanoparticles. Results: The nanoparticle sizes increase with the increase of reaction temperatures. It is observedthat the reaction time affects nanoparticle growth. The nanoparticles are studied by XRD, TEM,and magnetic measurements. Conclusion: This work presents a facile method to prepare nanoparticles with different sizes,which provides a fundamental understanding of nanoparticle growth in solution.
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- Award ID(s):
- 1912876
- PAR ID:
- 10403386
- Date Published:
- Journal Name:
- Current Chinese Chemistry
- Volume:
- 2
- Issue:
- 2
- ISSN:
- 2666-0016
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Lithium nickel manganese cobalt oxide (Li x Ni y Mn z Co 1−y−z O 2 , 0 < x , y , z < 1, also known as NMC) is a class of cathode materials used in lithium ion batteries. Despite the increasing use of NMC in nanoparticle form for next-generation energy storage applications, the potential environmental impact of released nanoscale NMC is not well characterized. Previously, we showed that the released nickel and cobalt ions from nanoscale Li 1/3 Ni 1/3 Mn 1/3 Co 1/3 O 2 were largely responsible for impacting the growth and survival of the Gram-negative bacterium Shewanella oneidensis MR-1 (M. N. Hang et al. , Chem. Mater. , 2016, 28 , 1092). Here, we show the first steps toward material redesign of NMC to mitigate its biological impact and to determine how the chemical composition of NMC can significantly alter the biological impact on S. oneidensis . We first synthesized NMC with various stoichiometries, with an aim to reduce the Ni and Co content: Li 0.68 Ni 0.31 Mn 0.39 Co 0.30 O 2 , Li 0.61 Ni 0.23 Mn 0.55 Co 0.22 O 2 , and Li 0.52 Ni 0.14 Mn 0.72 Co 0.14 O 2 . Then, S. oneidensis were exposed to 5 mg L −1 of these NMC formulations, and the impact on bacterial oxygen consumption was analyzed. Measurements of the NMC composition, by X-ray photoelectron spectroscopy, and composition of the nanoparticle suspension aqueous phase, by inductively coupled plasma-optical emission spectroscopy, showed the release of Li, Ni, Mn, and Co ions. Bacterial inhibition due to redesigned NMC exposure can be ascribed largely to the impact of ionic metal species released from the NMC, most notably Ni and Co. Tuning the NMC stoichiometry to have increased Mn at the expense of Ni and Co showed lowered, but not completely mitigated, biological impact. This study reveals that the chemical composition of NMC nanomaterials is an important parameter to consider in sustainable material design and usage.more » « less
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.2174/2666001601666211110093947
