Rapid Removal and Mineralization of Bisphenol A by
Heterosupramolecular Plasmonic Photocatalyst Consisting of Gold Nanoparticle-Loaded
Titanium(IV) Oxide and Surfactant Admicelle
posted on 2017-09-15, 00:00authored byShin-ichi Naya, Junpei Yamauchi, Takashi Okubo, Hiroaki Tada
The
establishment of technology for rapid and complete removal
and mineralization of harmful phenolic compounds from water is of
great importance for environmental conservation. Visible-light irradiation
(λ > 430 nm, light intensity integrated from 420 to 485 nm
=
6.0 mW cm–2) of Au nanoparticle (NP)-loaded TiO2 (Au/TiO2) in dilute aqueous solutions of bisphenol
A (BPA) and p-cresol (PC) causes degradation of the
phenols. The addition of trimethylstearylammonium chloride (C18TAC) enhances the adsorption of BPA on Au/TiO2 to greatly increase the rate of reaction. Consequently, 10 μM
phenols are completely removed from the solutions within 2.5 h irradiation,
and prolonging irradiation time to 24 h quantitatively oxidizes BPA
to CO2. Dynamic light scattering ζ-potential measurements
indicate that a C18TAC bilayer or admicelle is formed on
the Au/TiO2 particle surface at C18TAC concentration
>50 μM. The action spectrum for reaction shows that this
reaction
is driven by the Au NP localized surface plasmon resonance excitation-induced
interfacial electron transfer from Au to TiO2. We propose
a possible reaction scheme on the basis of the experimental results
including intermediate analysis.