Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation

Tetrachloroaurate(III) dissolved in dilute aqueous aqua regia is electrochemically reduced at boron-doped diamond electrodes to form gold metal. The reduction process is studied by voltammetric, SEM, and XPS techniques. Both the deposition of gold and the anodic stripping process are detected. The r...

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Hauptverfasser: Holt, K, Sabin, G, Compton, R, Foord, J, Marken, F
Format: Journal article
Sprache:English
Veröffentlicht: 2002
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author Holt, K
Sabin, G
Compton, R
Foord, J
Marken, F
author_facet Holt, K
Sabin, G
Compton, R
Foord, J
Marken, F
author_sort Holt, K
collection OXFORD
description Tetrachloroaurate(III) dissolved in dilute aqueous aqua regia is electrochemically reduced at boron-doped diamond electrodes to form gold metal. The reduction process is studied by voltammetric, SEM, and XPS techniques. Both the deposition of gold and the anodic stripping process are detected. The ratio of cathodic to anodic charge or stripping efficiency, Qanodic/Qcathodic, is shown to depend on the concentration of AuCl4- and on the pretreatment of the boron-doped diamond electrode surface. Cathodic pretreatment of the boron-doped diamond electrode considerably increases the rate for both deposition and stripping. In the presence of power ultrasound emitted from a glass horn system (24 kHz, 8 Wcm-2) the current associated with the reduction of AuCl4- is considerably enhanced and two components in the mass transport controlled limiting current are identified as (i) the deposition of gold onto the boron-doped diamond and (ii) the formation of colloidal gold.
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spelling oxford-uuid:25b4b5f8-298b-497c-9377-852147fbd7f02022-03-26T11:57:01ZReduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:25b4b5f8-298b-497c-9377-852147fbd7f0EnglishSymplectic Elements at Oxford2002Holt, KSabin, GCompton, RFoord, JMarken, FTetrachloroaurate(III) dissolved in dilute aqueous aqua regia is electrochemically reduced at boron-doped diamond electrodes to form gold metal. The reduction process is studied by voltammetric, SEM, and XPS techniques. Both the deposition of gold and the anodic stripping process are detected. The ratio of cathodic to anodic charge or stripping efficiency, Qanodic/Qcathodic, is shown to depend on the concentration of AuCl4- and on the pretreatment of the boron-doped diamond electrode surface. Cathodic pretreatment of the boron-doped diamond electrode considerably increases the rate for both deposition and stripping. In the presence of power ultrasound emitted from a glass horn system (24 kHz, 8 Wcm-2) the current associated with the reduction of AuCl4- is considerably enhanced and two components in the mass transport controlled limiting current are identified as (i) the deposition of gold onto the boron-doped diamond and (ii) the formation of colloidal gold.
spellingShingle Holt, K
Sabin, G
Compton, R
Foord, J
Marken, F
Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title_full Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title_fullStr Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title_full_unstemmed Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title_short Reduction of tetrachloroaurate (III) at boron-doped diamond electrodes: Gold deposition versus gold colloid formation
title_sort reduction of tetrachloroaurate iii at boron doped diamond electrodes gold deposition versus gold colloid formation
work_keys_str_mv AT holtk reductionoftetrachloroaurateiiiatborondopeddiamondelectrodesgolddepositionversusgoldcolloidformation
AT sabing reductionoftetrachloroaurateiiiatborondopeddiamondelectrodesgolddepositionversusgoldcolloidformation
AT comptonr reductionoftetrachloroaurateiiiatborondopeddiamondelectrodesgolddepositionversusgoldcolloidformation
AT foordj reductionoftetrachloroaurateiiiatborondopeddiamondelectrodesgolddepositionversusgoldcolloidformation
AT markenf reductionoftetrachloroaurateiiiatborondopeddiamondelectrodesgolddepositionversusgoldcolloidformation