Photocatalytic Recovery of Gold from a Non-Cyanide Gold Plating Solution as Au Nanoparticle-Decorated Semiconductors
2
Issued Date
2022-03-08
Resource Type
eISSN
24701343
Scopus ID
2-s2.0-85125962136
Journal Title
ACS Omega
Volume
7
Issue
9
Start Page
7683
End Page
7695
Rights Holder(s)
SCOPUS
Bibliographic Citation
ACS Omega Vol.7 No.9 (2022) , 7683-7695
Suggested Citation
Kunthakudee N., Puangpetch T., Ramakul P., Hunsom M. Photocatalytic Recovery of Gold from a Non-Cyanide Gold Plating Solution as Au Nanoparticle-Decorated Semiconductors. ACS Omega Vol.7 No.9 (2022) , 7683-7695. 7695. doi:10.1021/acsomega.1c06362 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/84099
Title
Photocatalytic Recovery of Gold from a Non-Cyanide Gold Plating Solution as Au Nanoparticle-Decorated Semiconductors
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
In this work, a photocatalytic process was carried out to recover gold (Au) from the simulated non-cyanide plating bath solution. Effects of semiconductor types (TiO2, WO3, Nb2O3, CeO2, and Bi2O3), initial pH of the solution (3-10), and type of complexing agents (Na2S2O3and Na2SO3) and their concentrations (1-4 mM each) on Au recovery were explored. Among all employed semiconductors, TiO2exhibited the highest photocatalytic activity to recover Au from the simulated spent plating bath solution both in the absence and presence of complexing agents, in which Au was completely recovered within 15 min at a pH of 6.5. The presence of complexing agents remarkably affected the size of deposited Au on the TiO2surface, the localized surface plasmon effect (LSPR) behavior, and the valence band (VB) edge position of the obtained Au/TiO2, without a significant change in the textural properties or the band gap energy. The photocatalytic activity of the obtained Au/TiO2tested via two photocatalytic processes depended on the common reduction mechanism rather than the textural or optical properties. As a result, the Au/TiO2NPs obtained from the proposed recovery process are recommended for use as a photocatalyst for the reactions occurring at the conduction band rather than at the valence band. Notably, they exhibited good stability after the fifth photocatalytic cycle for Au recovery from the actual cyanide plating bath solution.