A study of the surface oxidation of galena using cyclic voltammetry

Gardner, JR; Woods, R.

doi:10.1016/s0022-0728(79)80177-1

Cited by 114 publications

(40 citation statements)

References 11 publications

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“…The copper sulfide mineral system is an important source of copper in ore, as well as being a possible product of the leaching of other ternary copper chalcogenides such as chalcopyrite (4,5). Leaching of higher copper polymorphs such as digenite and anilite have been shown to leach to CuS 2 (2).…”

Section: Introductionmentioning

confidence: 99%

Formation Processes of Chemically Deposited Copper Sulfide Thin Films

2006

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Copper sulfide thin films and particles were prepared by chemical bath deposition. Bath compositions were altered as well as mechanical processes such as stirring of solutions during the deposition process to determine the effect on the resulting films. The films and particles that were formed homogeneously in the bath solutions were analysed by Raman spectroscopy, electron microscopy, X-ray diffraction and electrochemistry. By changing one of the complexing agents, films and particles with varying copper:sulfur ratios were formed. Films that were deposited while the solution stirred formed a thinner layer than those in which the solution was static during the deposition process. The effect of changing specific parameters included an improvement in adhesion properties, a decreased amount of particulate growth within the bath solution, a decrease in the thickness and roughness of the resulting films, and a change in stoichiometry, although these property changes were not always observed in the same system.

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Section: Introductionmentioning

confidence: 99%

Formation Processes of Chemically Deposited Copper Sulfide Thin Films

2006

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“…In the absence of Se, the PME with galena present in the cavity exhibits a cathodic peak at −440 mV (labeled C 0 in Figure 3a). This peak is likely indicative of the reduction of oxidized surface elemental S via the following reaction taken from [48][49][50]:…”

Section: Cyclic Voltammetry Of Galena With and Without Se(iv)mentioning

confidence: 99%

Electrochemical, Spectroscopic, and Computational Investigations on Redox Reactions of Selenium Species on Galena Surfaces

et al. 2019

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Despite previous studies investigating selenium (Se) redox reactions in the presence of semiconducting minerals, Se redox reactions mediated by galena (PbS) are poorly understood. In this study, the redox chemistry of Se on galena is investigated over a range of environmentally relevant Eh and pH conditions (+0.3 to −0.6 V vs. standard hydrogen electrode, SHE; pH 4.6) using a combination of electrochemical, spectroscopic, and computational approaches. Cyclic voltammetry (CV) measurements reveal one anodic/cathodic peak pair at a midpoint potential of +30 mV (vs. SHE) that represents reduction and oxidation between HSeO3− and H2Se/HSe−. Two peak pairs with midpoint potentials of −400 and −520 mV represent the redox transformation from Se(0) to HSe− and H2Se species, respectively. The changes in Gibbs free energies of adsorption of Se species on galena surfaces as a function of Se oxidation state were modeled using quantum-mechanical calculations and the resulting electrochemical peak shifts are (−0.17 eV for HSeO3−/H2Se, −0.07 eV for HSeO3−/HSe−, 0.15 eV for Se(0)/HSe−, and −0.15 eV for Se(0)/H2Se). These shifts explain deviation between Nernstian equilibrium redox potentials and observed midpoint potentials. X-ray photoelectron spectroscopy (XPS) analysis reveals the formation of Se(0) potentials below −100 mV and Se(0) and Se(−II) species at potentials below −400 mV.

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“…Gardner and Woods studied the redox chemistry of a single crystal sample of galena in aqueous solutions as a function of pH. It was found that in acidic HClO4 solutions anodic oxidation led to a soluble Pb species with a layer of amorphous sulfur forming on the electrode which restructures to become porous and enable further surface dissolution [17]. In basic solutions (pH 6.8 to 11) the principal product was lead oxide with some thiosulfate and sulfur.…”

Section: Figure 2: (A) Voltammogram Of 103 Mg Of Galena Paste On a Pmentioning

confidence: 99%

Paint casting: A facile method of studying mineral electrochemistry

Abbott

Bevan

Baeuerle

et al. 2017

Electrochemistry Communications

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The electrochemical properties of minerals are often difficult to study due to the need to maintain an electrical contact with the current collector. In this study it is shown that a paste of the powdered mineral can easily be made by mixing it with an ionic liquid and painting this onto an electrode surface. This enables voltammograms with high resolution and relatively low resistive artefacts to be obtained. The oxidative and reductive charge can be correlated to the loading of mineral on the electrode.

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A study of the surface oxidation of galena using cyclic voltammetry

Cited by 114 publications

References 11 publications

Formation Processes of Chemically Deposited Copper Sulfide Thin Films

Formation Processes of Chemically Deposited Copper Sulfide Thin Films

Electrochemical, Spectroscopic, and Computational Investigations on Redox Reactions of Selenium Species on Galena Surfaces

Paint casting: A facile method of studying mineral electrochemistry

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