Rapid and Complete Removal of Nonylphenol by Gold Nanoparticle/Rutile Titanium(IV) Oxide Plasmon Photocatalyst

Abstract

Nonylphenol is a harmful endocrine disruptor, and the concentration in ambient water should be restricted below 0.1 μM. We show that visible-light irradiation of gold nanoparticle (NP)-loaded rutile TiO2 (Au/rutile TiO2) plasmon photocatalyst leads to rapid and complete removal of nonylphenol from its dilute aqueous solution with the degradation. Au/rutile TiO2 exhibits much higher visible-light activity than Au/anatase TiO2 and BiVO4. Based on the results of the adsorption and Fourier-transformed infrared spectroscopic measurements, we present a unique reaction scheme consisting of a series of events, the fast oxidative adsorption and concentration of nonylphenol on the Au NP surface, the successive efficient oxidation induced by the localized surface plasmon resonance excitation-driven interfacial electron transfer from Au NP to rutile TiO2, and the regeneration of the adsorption sites by the surface transport of the intermediates from Au to TiO2.

Synthesis of spherical Ag/ZnO heterostructural composites with excellent photocatalytic activity under visible light and UV irradiation

“…However, it is proven that electrons are able to transfer from the Ag to ZnO due to its strong electron oscillating collectively on the SPR excitation [44] . These lead to interband excitation giving sufficient energy to the electrons to overcome the Schottky barrier at the interface [45] . A c c e p t e d M a n u s c r i p t photogenerated holes would transfer to the photocatalyst surface and directly oxidize the organic pollutants, resulting in an obviously improved photocatalytic activity [45][46] .…”

“…These lead to interband excitation giving sufficient energy to the electrons to overcome the Schottky barrier at the interface [45] . A c c e p t e d M a n u s c r i p t photogenerated holes would transfer to the photocatalyst surface and directly oxidize the organic pollutants, resulting in an obviously improved photocatalytic activity [45][46] . Similar phenomena were also observed in previous studies of Au/ZnO composite and Au/TiO 2 composite [36,47] .…”

A new bimetallic plasmonic photocatalyst consisting of gold(core)-copper(shell) nanoparticle and titanium(IV) oxide support

“…17,18 In this study, as a test reaction for examining the Cu shell effect, the mine oxidation was carried out using Au@Cu/TiO 2 , Au/TiO 2 , and CuO/TiO 2 as the photocatalysts. Visible-light irradiation (Xe lamp with an optical filter, λ > 430 nm, I 420−485 = 2 mW cm −2 ) of the photocatalyst in an aerated acetonitrile solution of benzylamine (100 µmol dm −3 ) selectively yielded benzaldehyde by hydrolysis of the imine.…”

“…Au/TiO 2 plasmonic photocatalysts have been applied to several oxidative chemical transformations including thiol to disulfide, 10 alcohol to carbonyl compounds, [11][12][13][14] benzene to phenol, 15,16 and amine to imine. 17,18 The studies on the plasmonic photocatalysts for the oxidative chemical transformations have so far used Au NP as the light harvesting component. If the Au surface of Au/TiO 2 can be chemically activated by the surface modification without damping of the LSPR, the activity could increase, and simultaneously, the application would greatly broaden.…”

Photocatalysis of titanium dioxide modified by catechol-type interfacial surface complexes (ISC) with different substituted groups

“…Therefore, the development of visible-light-sensitive TiO 2 photocatalyst has been a great concern for efficient utilization of solar light [6][7][8][9]. Visible-light-responsive TiO 2 photocatalysts have been designed by several methods such as doping with nitrogen and other elements [10][11][12][13][14], organic dye sensitizer [15], plasmonic Au and Ag nanoparticles [16][17][18][19], and interfacial surface complexes (ISC) [20][21][22][23][24][25][26][27][28][29][30].…”