Photocatalytic reduction and scavenging of Hg(ii) over templated-dewetted Au on TiO2 nanotubes

D. Spanu, A. Bestetti, H. Hildebrand, P. Schmuki, M. Altomare, S. Recchia*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)

Abstract

Gold-decorated TiO2 nanotubes were used for the photocatalytic abatement of Hg(II) in aqueous solutions. The presence of dewetted Au nanoparticles induces a strong enhancement of photocatalytic reduction and scavenging performances, with respect to naked TiO2. In the presence of chlorides, a massive formation of Hg2Cl2 nanowires, produced from Au nanoparticles, was observed using highly Au loaded photocatalysts to treat a 10 ppm Hg(II) solution. EDS and XPS confirmed the nature of the photoproduced nanowires. In the absence of chlorides and/or at lower Hg(II) starting concentrations, the scavenging of mercury proceeds through the formation of Hg–Au amalgams. Solar light driven Hg(II) abatements up to 90% were observed after 24 h. ICP-MS analysis revealed that the removed Hg(II) is accumulated on the photocatalyst surface. Regeneration of Hg-loaded exhaust photocatalysts was easily performed by anodic stripping of Hg(0) and Hg(I) to Hg(II). After four catalytic-regeneration cycles, only a 10% decrease of activity was observed.
Original languageEnglish
Pages (from-to)1046-1055
JournalPhotochemical and Photobiological Sciences
Volume18
DOIs
Publication statusPublished - May 2019
Externally publishedYes

Keywords

  • n/a OA procedure

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