| 1. |
- Ren, Peng, et al.
(författare)
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An Atomically Dispersed Mn-Photocatalyst for Generating Hydrogen Peroxide from Seawater via the Water Oxidation Reaction (WOR)
- 2023
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Ingår i: Journal of the American Chemical Society. - 0002-7863 .- 1520-5126. ; 145:30, s. 16584-16596
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we have fabricatedan aryl amino-substitutedgraphiticcarbon nitride (g-C3N4) catalyst with atomicallydispersed Mn capable of generating hydrogen peroxide (H2O2) directly from seawater. This new catalyst exhibitedexcellent reactivity, obtaining up to 2230 & mu;M H2O2 in 7 h from alkaline water and up to 1800 & mu;Mfrom seawater under identical conditions. More importantly, the catalystwas quickly recovered for subsequent reuse without appreciable lossin performance. Interestingly, unlike the usual two-electron oxygenreduction reaction pathway, the generation of H2O2 was through a less common two-electron water oxidation reaction(WOR) process in which both the direct and indirect WOR processesoccurred; namely, photoinduced h(+) directly oxidized H2O to H2O2 via a one-step 2e(-) WOR, and photoinduced h(+) first oxidized a hydroxide (OH-) ion to generate a hydroxy radical ((OH)-O-& BULL;), and H2O2 was formed indirectly by thecombination of two (OH)-O-& BULL;. We have characterized thematerial, at the catalytic sites, at the atomic level using electronparamagnetic resonance, X-ray absorption near edge structure, extendedX-ray absorption fine structure, high-resolution transmission electronmicroscopy, X-ray photoelectron spectroscopy, magic-angle spinningsolid-state NMR spectroscopy, and multiscale molecular modeling, combiningclassical reactive molecular dynamics simulations and quantum chemistrycalculations.
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| 2. |
- Rodrigues, Bruno Vinicius Manzolli, et al.
(författare)
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Selective electrochemical recoveries of Cu and Mn from end-of-life Li-ion batteries
- 2023
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Ingår i: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- Lithium-ion batteries (LIBs) are a tremendous achievement in the current energy storage landscape. However, there is an increasing demand for their implementation due to a variety of applications, such as mobile devices and a growing market of electric vehicles. Hence, the recycling of end-of-life batteries is one of the ways to satisfy the need for manufacturing new ones; however, this is challenging due to the lack of sustainable and efficient methods on a large scale. Electrochemical methods are widely used in the production of metals and alloys, therefore constituting a promising way for the recovery of critical metals present in cathode materials in LIBs. In this work, cathode materials have been collected from used LIBs from different sources and leached altogether with sulphuric acid and hydrogen peroxide. The resulting solution was treated electrochemically by applying a constant potential of-0.5 V for 20 h, which promoted the selective separation of copper and manganese at the cathode and anode sides, respectively. Complete and selective recoveries of Cu and Mn were proved by ICP-OES methods, while the purity of the obtained products was assessed by XRD, oS and SEM-EDS analysis. This investigation presents a great potential for the implementation of an electrochemical treatment to recover valuable metals in pure and ready to reuse form from spent LIBs, which can be easily scaled-up as an alternative to current non-green recovery processes.
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