Detection of sulphur and polysulphides on electrochemically oxidized pyrite surfaces by X-ray photoelectron spectroscopy and Raman spectroscopy

Mycroft, J.R.; Bancroft, G.M.; McIntyre, N. S.; Lorimer, John W.; Hill, Ian R.

doi:10.1016/0022-0728(90)87332-e

Cited by 248 publications

(135 citation statements)

References 35 publications

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“…The realgar As 3d 5/2 peak is located at 43.1 eV lower than that of orpiment at 43.5 eV BE [16]. The BE of the S 2p 3/2 peak in realgar was 162.5 eV which can be interpreted as disulphide (S 2� 2 ) in realgar [17]. Also the S/As atomic ratio calculated was close to the expected value for As 4 were observed because their BEs of As 3d 5/2 are located at about 46.1 and 44.4-45.1 eV [18], respectively.…”

Section: Formation Of As 4 S 4 Nanocompositesmentioning

confidence: 91%

Preparation, characterisation and antimicrobial activities of polymer/realgar nanocomposites

Cheng

Zhang

2013

Journal of Experimental Nanoscience

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Preparation and study of homogeneous nanoparticles (NPs) have been an important area of research in recent years. In this work, we describe a polymerprotected method for the preparation and formation of realgar nanocomposites with various average diameters. Two types of macromolecules were selected and their interactions with nanorealgar were studied by spectrometric methods. It is found that the starch has a significant effect on the formation and growth of homogeneous nanorealgar with an average diameter of 30 nm. In the case of using polyvinylpyrrolidone (PVP) as a protecting polymer, the realgar NP size is in the range of 20-80 nm, with an average value of 55 nm. The polymer-protected nanorealgar shows superior antimicrobial activity against Escherichia coli and Staphylococcus aureus, whereas the bulky realgar colloid formed in aqueous solution has much less antimicrobial activity. The antimicrobial activity followed the order As 4 S 4 -starch NPs 4 As 4 S 4 -PVP NPs 4 As 4 S 4 NPs, which suggests small realgar NPs are more favourable.

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Section: Formation Of As 4 S 4 Nanocompositesmentioning

confidence: 91%

Preparation, characterisation and antimicrobial activities of polymer/realgar nanocomposites

Cheng

Zhang

2013

Journal of Experimental Nanoscience

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“…For calibration purposes, a Si wafer disc (521 cm −1 ) was used. The vibrational range was from 100 to 750 cm −1 , as the S n 2− , the S 0 , and main copper-bearing compounds show their main active modes within this interval [10,11]. At least 10 Raman spectra were collected for each sample.…”

Section: Surficial Analyses After the Biooxidation Of Mce*-rssmentioning

confidence: 99%

Bioelectrochemical Changes during the Early Stages of Chalcopyrite Interaction with Acidithiobacillus Thiooxidans and Leptospirillum sp.

2017

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Abstract:A bioelectrochemical study of charge transfer in the biofilm-chalcopyrite interface was performed to investigate the effect of surficial reduced sulfur species (RSS), in the form of non-stochiometric compounds or polysulfides (S n 2− ) and elemental sulfur (S 0 ) on a biofilm structure, during the earliest stages (1, 12 and 24 h) of chalcopyrite biooxidation by Acidithiobacillus thiooxidans alone and adding Leptospirillum sp. The surface of massive chalcopyrite electrodes was exposed to the bacteria, which were analyzed electrochemically, spectroscopically, and microscopically. At the studied earlier times, charge transfer and significant differences in the biofilm structure were detected, depending on the presence of Leptospirillum sp. acting on A. thiooxidans biofilms. Such differences were a consequence of a continuous chalcopyrite pitting and promoting changes in biofilm hydrophobicity. A. thiooxidans modifies the reactive properties of RSS and favors an acidic dissolution, which shifts into ferric dissolution when Leptospirillum sp. is present. A. thiooxidans allows H + and Fe 3+ diffusion, and Leptospirillum sp. enables to surpass the charge transfer (reactivity) barrier between the mineral interface and the ions. The observed changes of hydrophobicity on the interface are associated to ions and electrons activity and transfer. Finally, a model of S 0 biooxidation by A. thiooxidans alone or with Leptospirillum sp. is proposed.

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“…The identification of the reaction products at the pyrite/aqueous interface is important for understanding the mechanism of pyrite dissolution. However, the small amount of reaction products on the pyrite surface makes direct analysis very difficult (Mycroft et al, 1990;Khan et al, 1992;Wang et al, 1992;Zhu et al, 1993). Therefore, in an effort to obtain a meaningful electrochemical response and more quantitative information about the reaction products, the use of pyrite in a highly divided form, as microelectrodes, would be advantageous because of the increase in the amount of reaction surface per given pyrite/solution mass ratio.…”

Section: Pyrite Aqueous Systemsmentioning

confidence: 99%

“…; Buckley et al, 1988;Osseo-Asare, 1988, 1992;Mycroft et al, 1990;Wang et al, 1992;Zhu et al, 1993). However, the small amount of reaction products on pyrite surface makes direct analysis very difficult.…”

mentioning

confidence: 99%

Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

Osseo‐Asare¹,

Wei²

1996

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Detection of sulphur and polysulphides on electrochemically oxidized pyrite surfaces by X-ray photoelectron spectroscopy and Raman spectroscopy

Cited by 248 publications

References 35 publications

Preparation, characterisation and antimicrobial activities of polymer/realgar nanocomposites

Preparation, characterisation and antimicrobial activities of polymer/realgar nanocomposites

Bioelectrochemical Changes during the Early Stages of Chalcopyrite Interaction with Acidithiobacillus Thiooxidans and Leptospirillum sp.

Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

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