On the Origin of Enhanced Photocatalytic Activity of Copper-Modified Titania in the Oxidative Reaction Systems

Abstract

Modification of titania with copper is a promising way to enhance the photocatalytic performance of TiO 2 . The enhancement means the significant retardation of charge carriers' recombination ratio and the introduction of visible light activity. This review focuses on two main ways of performance enhancement by copper species-i.e., originated from plasmonic properties of zero-valent copper (plasmonic photocatalysis) and heterojunctions between semiconductors (titania and copper oxides). The photocatalytic performance of copper-modified titania is discussed for oxidative reaction systems due to their importance for prospective applications in environmental purification. The review consists of the correlation between copper species and corresponding variants of photocatalytic mechanisms including novel systems of cascade heterojunctions. The problem of stability of copper species on titania, and the methods of its improvement are also discussed as important factors for future applications. As a new trend in the preparation of copper-modified titania photocatalyst, the role of particle morphology (faceted particles, core-shell structures) is also described. Finally, in the conclusion section, perspectives, challenges and recommendations for future research on copper-modified titania are formulated.

Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization

“…Central limit for the TiO 2 based systems, besides the rate of recombination of the hole-electron pairs, is related to the wide band gap of this semiconductor which makes it suitable only for UV light absorption, with the consequent absence of photoactivity in the visible region of solar spectrum. To overcome the TiO 2 limit, different strategies have been proposed, such as doping with metal [7] or non-metal [8] atoms, combination with other semiconductors [9] or deposition of noble metal particles on the oxide surface [10]. Composite semiconductor systems like Cu 2 O/TiO 2 are being in development to overcome the above mentioned TiO 2 limits.…”

Efficient Photocatalysts Made by Uniform Decoration of Cu2O Nanoparticles on Si Nanowire Arrays with Low Visible Reflectivity

“…The charge recombination would then dominate the photochemical reactions, and therefore [24], the resulting photodegradation efficiency was greatly limited in the presence of pure SiNW array as photocatalysts. With the decoration of Cu 2 O nanoparticles on SiNWs, the electron-hole recombination was effectively retarded through scavenging the photogenerated electrons [25, 26]. This conclusion could be supported by the improved photodegradation rates of three Cu 2 O-incorporated Si, as shown in Fig.…”

Low-Cost Synthesis of Cu-Modified Immobilized Nanoporous TiO2 for Photocatalytic Degradation of 1H-Benzotriazole

“…Because noble metals are rare and expensive, copper is a good candidate to replace them. The improved photocatalytic activity was found particularly for TiO 2 modifications with low Cu concentrations [30][31][32]. Copper nanoparticles (NP), similar to noble metal nanoparticles, are promising surface modifiers of TiO 2 because they restrict the recombination of electron-hole pairs, which leads to enhanced photocatalytic activity both under UV and visible light irradiation.…”