Characterization and photostability of Cu2O–Ag–AgBr/Al2O3 for the degradation of toxic pollutants with visible-light irradiation

Abstract

a b s t r a c tA plasmonic photocatalyst Cu 2 O-Ag-AgBr supported on mesoporous alumina (Cu 2 O-Ag-AgBr/Al 2 O 3 ) was prepared by deposition-precipitation methods. The samples were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results indicated that Cu 2 O-Ag-AgBr nanojunctions were formed by the contact of Cu 2 O, AgBr and Ag with each other. The catalyst showed high photocatalytic activity and stability for the degradation of toxic persistent organic pollutants under visible light irradiation. The release of metal ions from the catalyst was significantly inhibited during the photodegradation of pollutants. Four interfacial electron transfer process were verified in the photoreaction system of Cu 2 O-Ag-AgBr/Al 2 O 3 on the basis of electron spin resonance and cyclic voltammetry analyses under a variety of experimental conditions. The results indicated that the coupling of Cu 2 O with Ag NPs and AgBr not only accelerated interfacial electron transfer processes, leading to the fast photoreduction of the dissolved Ag + and the photostability of Cu 2 O. These findings could be useful for the practical application of plasmonic visible light photocatalyst and photovoltaic fuel cells.

Facet-Dependent Cuprous Oxide Nanocrystals Decorated with Graphene as Durable Photocatalysts under Visible Light

“…1.92 eV vs. normal hydrogen electrode (NHE)) of rhombic dodecahedra Cu 2 O (mainly {110} facets) also can degrade more MO molecules (ca. 1.48 eV vs. NHE) [ 51 , 52 ] since the number of dangling Cu atoms on the {110} plane per unit surface area was nearly 1.5 times higher than that on the {111} plane, resulting in a more positively charged surface on {110} facets [ 28 ]. Therefore, the superoxide radical anions, hydrogen peroxide and h + may be the dominant species governing the photodegradation of MO under visible-light irradiation.…”

The fabrication and characterization of CeO2/Cu2O nanocomposites with enhanced visible-light photocatalytic activity

“…Organic dyes are extensively applied in industrial production, causing the emergence of environmental issues and affecting human health. 28,29 Therefore, MO solution was chosen as the simulated pollutant to evaluate the photocatalyst activity. The photodegradation properties of the samples for an MO solution were measured.…”

Charge Transport in Two‐Photon Semiconducting Structures for Solar Fuels

“…As one constituent element of the photocatalysts is same as the metallic mediator, such as in W 18 O 49 /Ag/AgCl, Cu 2 O/Ag/AgBr‐Al 2 O 3 , AgBr/Ag/TiO 2 , TNT/Ag/AgBr, AgBr/Ag/Bi 2 WO 6 , AgBr/Ag/g‐C 3 N 4 , AgBr/Ag/Bi 2 MoO 6 , Ag 3 PO 4 /Ag/AgI, Ag 3 PO 4 /Ag/WO 3− x , AgI/Ag/AgBr, and AgBr/Ag/MoO 3 , there exists a concentration equilibrium between the metal and its ions. The intimate contact interface between the conductor and the catalyst presents low electric resistance that is beneficial for the formation of an ohmic contact.…”