| 1. |
- Birdsong, Björn K., et al.
(författare)
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Large-scale synthesis of 2D-silica (SiOx) nanosheets using graphene oxide (GO) as a template material
- 2023
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 15:31, s. 13037-13048
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Tidskriftsartikel (refereegranskat)abstract
- Graphene oxide (GO) was used in this study as a template to successfully synthesize silicon oxide (SiOx) based 2D-nanomaterials, adapting the same morphological features as the GO sheets. By performing a controlled condensation reaction using low concentrations of GO (<0.5 wt%), the study shows how to obtain 2D-nanoflakes, consisting of GO-flakes coated with a silica precursor that were ca. 500 nm in lateral diameter and ca. 1.5 nm in thickness. XPS revealed that the silanes had linked covalently with the GO sheets at the expense of the oxygen groups present on the GO surface. The GO template was shown to be fully removable through thermal treatment without affecting the nanoflake morphology of the pure SiOx-material, providing a methodology for large-scale preparation of SiOx-based 2D nanosheets with nearly identical dimensions as the GO template. The formation of SiOx sheets using a GO template was investigated for two different silane precursors, (3-aminopropyl) triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS), showing that both precursors were capable of accurately templating the graphene oxide template. Molecular modeling revealed that the choice of silane affected the number of layers coated on the GO sheets. Furthermore, rheological measurements showed that the relative viscosity was significantly affected by the specific surface area of the synthesized particles. The protocol used showed the ability to synthesize these types of nanoparticles using a common aqueous alcohol solvent, and yield larger amounts (∼1 g) of SiOx-sheets than what has been previously reported.
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| 2. |
- Hoogendoorn, Billy W., et al.
(författare)
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Cellulose-assisted electrodeposition of zinc for morphological control in battery metal recycling
- 2022
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Ingår i: Materials Advances. - : Royal Society of Chemistry (RSC). - 2633-5409.
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose nanofibers (CNF) are demonstrated as an effective tool for converting electrodeposits into more easily detachable dendritic deposits useful in recycling zinc ion batteries via electrowinning. The incorporation of CNF at concentrations ranging from 0.01 to 0.5 g/L revealed a progressively extensive formation of a nacre-like dendritic zinc structure that did not form in its absence. Increasing CNF-concentrations from 0.01 to 0.5 g/L resulted in more extensive dendritic structures forming. The explanation to the observed phenomenon is the CNFs ability to strongly interact with the metal ions, i.e., restricting the mobility of the ions towards the electrowinning electrode. At the highest concentration of CNF (0.5 g/L), in combination with the lowest current density (150 A/m2), the electrodeposition was limited to the extent that formed deposits were almost non-existent. The electrodeposition in the presence of CNF was further evaluated at different temperatures: 20, 40 and 60°C. The dendritic formation was increasingly suppressed with increasing temperatures, and at a temperature of 60°C, the electrodeposited morphologies could not be differentiated from the morphologies formed in the absence of the cellulose. The results stemmed from a greater mobility of the metal ions at elevated temperatures, while at the same time suggests an inability of the CNF to strongly associate the metal ions at the elevated temperatures. High-pressure blasted titanium electrodes were used a reference material for accurate comparisons, and electron microscopy (FE-SEM) and X-ray diffraction were used to characterize the zinc morphologies and crystallite sizes, respectively. The article reports the first investigation on how dispersions of highly crystalline cellulose nanofibers can be used as a renewable and functional additive during the recycling of battery metal ions. The metal-ion/cellulose interactions may also allow for structural control in electrodeposition for other applications.
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| 3. |
- Hoogendoorn, Billy W., et al.
(författare)
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Cellulose nanofibers (CNFs) in the recycling of nickel and cadmium battery metals using electrodeposition
- 2023
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Ingår i: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 5:19, s. 5263-5275
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose nanofibers (CNFs) were employed in the aqueous electrodeposition of nickel and cadmium for battery metal recycling. The electrowinning of mixed Ni-Cd metal ion recycling solutions demonstrated that cadmium with a purity of over 99% could be selectively extracted while leaving the nickel in the solution. Two types of CNFs were evaluated: negatively charged CNFs (a-CNF) obtained through acid hydrolysis (−75 μeq. g−1) and positively charged CNFs (q-CNF) functionalized with quaternary ammonium groups (+85 μeq. g−1). The inclusion of CNFs in the Ni-Cd electrolytes induced growth of cm-sized dendrites in conditions where dendrites were otherwise not observed, or increased the degree of dendritic growth when it was already present to a lesser extent. The augmented dendritic growth correlated with an increase in deposition yields of up to 30%. Additionally, it facilitated the formation of easily detachable dendritic structures, enabling more efficient processing on a large scale and enhancing the recovery of the toxic cadmium metal. Regardless of the charged nature of the CNFs, both negatively and positively charged CNFs led to a significant formation of protruding cadmium dendrites. When deposited separately, dendritic growth and increased deposition yields remained consistent for the cadmium metal. However, dendrites were not observed during the deposition of nickel; instead, uniformly deposited layers were formed, albeit at lower yields (20%), when positively charged CNFs were present. This paper explores the potential of utilizing cellulose and its derivatives as the world's largest biomass resource to enhance battery metal recycling processes.
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| 4. |
- Hoogendoorn, Billy W.
(författare)
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Exploring cellulose as a biomacromolecule for enhanced battery metal ion recovery/recycling
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The research focused on the effects of integrating nanocellulose in the solidification of metal ions into metal oxide particles or metallic electrodeposits. Firstly, the cellulose was isolated as highly crystalline ca. 15-25 nm thick and 500 nm long fibers from bacterial cellulose using acid hydrolysis and had a negative surface charge. Positively charged nanocellulose was also explored using cationic functional groups substituted onto the nanofiber surface. The effect of the isolated nanocellulose when preparing metal oxides via enforced precipitation of zinc metal ions into zinc oxide particles was investigated at ultra-low nanocellulose content ≤0.01 %. The result indicated that increased reaction yields of ~15 % and a reduction of particle sizes by up to 50 % could occur at nanocellulose concentrations of 0.01 %. The kinetics was studied and showed that the presence of cellulose consistently increased the consumption rates of zinc ions. If the reaction consumed a large fraction of the zinc-ions (>80%) within the first 15 min, continued growth of ZnO was also suppressed by the presence of nanocellulose. This was observed during the synthesis of sheet-like ZnO-particles, where an increase in reaction yield from 81 to 95 % hindered the growth of additional nanorods, which otherwise had formed after 15 min of the reaction. Further, nanocellulose was then evaluated for metal recovery reactions of Zn, Cd, and Ni using electrodeposition. Zinc and cadmium, which generally form separate, faceted metal particles during electrodeposition, grew large dendrites when nanocellulose was present in the electrolyte. In the case of cadmium, the formation of dendrites was correlated with increases in yield by up to 15 %. For nickel, which always deposited as uniform and non-faceted layers, the presence of nanocellulose did not result in dendritic deposits. While the presence of 0.05 % of nanocellulose did not affect the yield for negatively charged nanocellulose, positively charged nanocellulose decreased the deposited amount by up to ca. 20 %. The temperature was also used to tune the dendritic formation during the zinc deposition. The major finding was that while the zinc electrodeposition in the presence of nanocellulose at 20 or 40°C induced dendritic growth, a similar deposition at 60 °C did not, reverting the deposition towards promoting dense and faceted zinc particles. The research on integrating nanocellulose in metal oxide particle solidification and metal recovery using electrodeposition aligns with the United Nations' Sustainable Development Goals (SDGs), particularly Goal 12: Responsible Consumption and Production, and Goal 1: End poverty in all its forms everywhere, but also Goal 13: Climate Action. The use of nanocellulose as an additive can contribute to sustainable consumption and production practices, reducing waste and conserving natural resources. This approach can help to address the challenge of meeting growing demands for metals used in various industrial applications, particularly those associated with battery manufacturing. Recycling valuable metals using nanocellulose can reduce the environmental impact of mining and processing ores, contributing to sustainable resource management and contribute to poverty reduction for creating job opportunities. Furthermore, the use of nanocellulose in electrodeposition reactions will help to combat climate change by promoting more efficient and environmentally friendly metal recovery methods, potentially reducing the carbon footprint associated with traditional metal recovery and mitigate the environmental impacts of metal extraction and mining. Overall, the research on integrating nanocellulose in metal oxide particle solidification and metal recovery using electrodeposition demonstrates innovative and sustainable solutions for resource management, contributing to the UN's SDGs.
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| 5. |
- Hoogendoorn, Billy W., et al.
(författare)
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Formation of Different Zinc Oxide Crystal Morphologies Using Cellulose as Nucleation Agent in the Waste Valorization and Recycling of Zn-Ion Batteries
- 2023
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Ingår i: Rare Metal Technology 2023. - Cham : Springer.
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Konferensbidrag (refereegranskat)abstract
- The formation of zinc oxide particles of different hierarchical morphologies was investigated. By performing elemental analysis on samples extracted from the supernatant solution during precipitations yielding two distinctly different morphologies, the consumption of zinc ions was used to follow the liquid-to-solid phase formation. While a rapid Zn-ion consumption was synonymous with the formation of predominantly oxygen terminated flower-shaped ZnO-particles, with half of the zinc ions being precipitated during the first minute, less than 10% of the zinc ions were converted to sea urchin-shaped ZnO-particles (with mixed terminations) after 1 min of the reaction. The unique ZnO-particle morphologies may therefore be related to the precipitation rates, which can be further explored as a tool for understanding how ZnO-particles with differently facetted surfaces form. Interestingly, the different formation rates remained with identical patterns when 0.5 g/L cellulose (0.005 wt%) was added to the reactions as nucleating agent for improved yields. The controlled formation of specific functional ZnO-particle surfaces is an important method for recycling inexpensive zinc waste from batteries to high value materials useful in a variety of catalytic applications.
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| 6. |
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| 7. |
- Hoogendoorn, Billy W., et al.
(författare)
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Ultra-low Concentration of Cellulose Nanofibers (CNFs) for Enhanced Nucleation and Yield of ZnO Nanoparticles
- 2022
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 38:41, s. 12480-12490
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose nanofibers (CNFs) were used in aqueous synthesis protocols for zinc oxide (ZnO) to affect the formation of the ZnO particles. Different concentrations of CNFs were evaluated in two different synthesis protocols producing distinctly different ZnO morphologies (flowers and sea urchins) as either dominantly oxygen-or zinc-terminated particles. The CNF effects on the ZnO formation were investigated by implementing a heat-treatment method at 400 degrees C that fully removed the cellulose material without affecting the ZnO particles made in the presence of CNFs. The inorganic phase formations were monitored by extracting samples during the enforced precipitations to observe changes in the ZnO morphologies. A decrease in the size of the ZnO particles could be observed for all synthesis protocols, already occurring at small additions of CNFs. At as low as 0.1 g/L CNFs, the particle size decreased by 50% for the flower-shaped particles and 45% for the sea-urchin-shaped particles. The formation of smaller particles was accompanied by increased yield by 13 and 15% due to the CNFs' ability to enhance the nucleation, resulting in greater mass of ZnO divided among a larger number of particles. The enhanced nucleation could also be verified as useful for preventing secondary morphologies from forming, which grew on the firstly precipitated particles. The suppression of secondary growths' was due to the more rapid inorganic phase formation during the early phases of the reactions and the faster consumption of dissolved salts, leaving smaller amounts of metal salts present at later stages of the reactions. The findings show that using cellulose to guide inorganic nanoparticle growth can be predicted as an emerging field in the preparation of functional inorganic micro/nanoparticles. The observations are highly relevant in any industrial setting for the large-scale and resource-efficient production of ZnO.
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| 8. |
- Xiao, Xiong, et al.
(författare)
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Ultrasound-assisted extraction of metals from Lithium-ion batteries using natural organic acids
- 2021
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 23:21
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Tidskriftsartikel (refereegranskat)abstract
- An ultrasound-assisted extraction (leaching) method of valuable metals from discarded lithium-ion batteries (LiBs) is reported. Mild organic citric or acetic acids were used as leaching agents for a more environmentally-friendly recovery of the lithium, nickel, cobalt, and manganese from the discharged and crushed lithium nickel-manganese-cobalt oxide (NMC) LiBs. The extraction was performed with the presence/absence of continuous ultrasound (US) energy supplied by a 110 W ultrasonic bath. The effect of temperature (30-70 °C), reducing agent concentration (H2O2: 0-2.0 vol%), as well as choice of specific acid on the metal dissolution were investigated. The US leaching decreased the leaching time by more than 50% and improved the leached percentage of Li, Mn, Co, and Ni due to the local heat and improved mass transfer between solid and liquid interfaces in the process. The X-ray diffraction results of residues from the US leaching further confirmed an improved dissolution of the crushed layered NMC structure, resulting in the significant improvement of the leached amounts of the valuable metals. Furthermore, it is demonstrated that using citric acid eliminated the need of additional reducing agents and suppressed the dissolution of copper (Cu) due to its inhibitor effect on the Cu surface, i.e. compared with using acetic acid as leaching reagent. Overall, it is shown that recovery of the battery metals can be facilitated and carried out in a more energy-efficient manner at low temperatures (50 °C) using ultrasound to improve metal ions mass transportation in the residue layers of the NMC during the organic acid leaching.
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