Unraveling the Coordination Geometry of Copper(II) Ions in Aqueous Solution through Absorption Intensity

Gómez-Salces, Susana; Aguado, Fernando; Valiente, Rafael; Rodríguez, F.

doi:10.1002/ange.201202033

Cited by 9 publications

(1 citation statement)

References 24 publications

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“…The dissolution of copper is evident from the immediate blue coloration of the solution yet some precipitate remains. [ 51 ] Subsequently, citric acid is added in a 1:1 molar ratio, which allows the full dissolution of the copper (II) formate, and the pH is adjusted to 7 by means of ammonia. The addition of ammonia leads to ligand exchange, as the blue coloration deepens significantly as a result from the higher ligand field.…”

Section: Resultsmentioning

confidence: 99%

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production

Joos

Elen

Ham

et al. 2023

Advanced Sustainable Systems

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A new benign aqueous route toward bismuth‐containing photoelectrodes is proposed to eliminate the need for harmful organic solvents and/or acids. A CuBi2O4 photocathode is prepared by stabilizing the metal ions through complexation in pH neutral aqueous solutions. Merits of the proposed approach are elemental homogeneity (with unique doping possibilities) and ease of fabrication (e.g., high scalability). The prepared aqueous CuBi2O4 precursor forms a nearly phase‐pure kusachiite crystalline phase free of organics residuals and capable of water reduction due to its sufficiently negatively positioned conduction band at −0.4 V versus RHE. Deposition on fluorine doped tin oxide coated glass (FTO/glass) substrates and thermal treatment leads to uniform but granular films of CuBi2O4 with excellent control over stoichiometry and thickness, owing to the facile and non‐destructive synthesis conditions. Ultimately, the optimized CuBi2O4 photocathodes produce AM1.5G photocurrent densities of up to −1.02 mA cm−2 at 0.4 V versus RHE with H2O2 as an electron scavenger, competing with bare CuBi2O4 prepared through less benign non‐aqueous organic synthesis routes.

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Section: Resultsmentioning

confidence: 99%

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production

Joos

Elen

Ham

et al. 2023

Advanced Sustainable Systems

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Hydroxy‐Carboxylic Acids as Green and Abundant Ligands for Sustainable Recovery of Copper from a Multimetallic Powder: A Proof of Concept

Ostellari,

Tapparelli,

Bragaggia

et al. 2024

ChemSusChem

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The recovery of copper and other valuable metals had become increasingly strategic for the future of the global economy, particularly in regions lacking abundant mineral resources, such as most European countries. In this study, we investigated the viability of utilizing environmentally friendly, cost‐effective, abundant and bio‐based ligands, specifically carboxylic acids and their derivatives, for copper leaching in a low‐temperature hydrometallurgical process. Our investigation focused on elucidating the impact of substituents in the α position of hydroxy‐carboxylic acids on copper solubilization efficacy. Notably, hydroxy‐carboxylic acids, like malic acid and lactic acid, were evidenced as particularly promising ligands for leaching copper from a custom‐made multimetallic powder. By thoroughly characterizing the obtained complexes (Raman, UV‐Vis) and by supporting the experimental efforts by a Design of Experiment (DoE) approach, we optimized the leaching process. The influence of experimental parameters such as pH, temperature, leaching time, and Cu/ligand molar ratio on process yield (determined through Inductively Coupled Plasma – Optical Emission Spectroscopy, ICP‐OES, analysis) was thoroughly investigated. Additionally, we developed a subsequent copper recovery step by precipitating copper (II) hydroxide in an alkaline environment, guided by speciation diagrams tailored for each copper‐ligand system.

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Can metal ion complexes be used as polarizing agents for solution DNP? A theoretical discussion

2013

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Dynamic nuclear polarization (DNP) can be used to dramatically increase the NMR signal intensities in solutions and solids. DNP is usually performed using nitroxide radicals as polarizing agents, characterized by sharp EPR lines, fast rotation, fast diffusion, and favorable distribution of the unpaired electron. These features make the nitroxide radicals ideally suited for solution DNP. Here, we report some theoretical considerations on the different behavior of some inorganic compounds with respect to nitroxide radicals. The relaxation profiles of slow relaxing paramagnetic metal aqua ions [copper(II), manganese(II), gadolinium(III) and oxovanadium(IV)] and complexes have been re-analyzed according to the standard theory for dipolar and contact relaxation, in order to estimate the coupling factor responsible for the maximum DNP enhancement that can be achieved in solution and its dependence on field, temperature and relative importance of outer-sphere versus inner-sphere relaxation.

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Unraveling the Coordination Geometry of Copper(II) Ions in Aqueous Solution through Absorption Intensity

Cited by 9 publications

References 24 publications

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production

Hydroxy‐Carboxylic Acids as Green and Abundant Ligands for Sustainable Recovery of Copper from a Multimetallic Powder: A Proof of Concept

Can metal ion complexes be used as polarizing agents for solution DNP? A theoretical discussion

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Unraveling the Coordination Geometry of Copper(II) Ions in Aqueous Solution through Absorption Intensity

Cited by 9 publications

References 24 publications

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi2O4 Photocathodes for Solar Hydrogen Production

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi2O4 Photocathodes for Solar Hydrogen Production

Hydroxy‐Carboxylic Acids as Green and Abundant Ligands for Sustainable Recovery of Copper from a Multimetallic Powder: A Proof of Concept

Can metal ion complexes be used as polarizing agents for solution DNP? A theoretical discussion

Contact Info

Product

Resources

About

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi₂O₄ Photocathodes for Solar Hydrogen Production