Catalytic properties of ruthenium oxide on n-type semiconductors under illumination

Abstract

The photoelectrochemical properties of Ti02 single-crystal electrodes on which a small amount of RuQ2 is deposited were investigated. From the increase of cathodic current around the flat band potential and the negative potential shift of Ru02 on Ti02 under illumination, Ru02 on n-type semiconductors such as Ti02 and CdS is concluded to play a role as a reduction catalyst for the water-splitting reaction and other hydrogen-evolution reactions. A remarkable catalytic effect of Ru02 on powdered Ti02 for hydrogen evolution and the isotope effect on hydrogen evolution from an ethanol-water mixture support this idea. The dependence of oxygen-evolution rate on the molar ratio of Ru02 to Ti02 behaves quite differently depending on the kind of electron acceptor. In the presence of Ag+ as an electron acceptor, RuOz on powdered TiÓ2 suppresses photocatalytic oxygen evolution. A negative shift of the potential of RuQ2 on a Ti02 single crystal under irradiation indicates that RuOa on Ti02 functions as a reduction site for photocatalytic oxygen evolution in the presence of a strong electron acceptor such as Ag+ or Fe3+.

Visible Light-Driven H2 Production over Highly Dispersed Ruthenia on Rutile TiO2 Nanorods

“…16 Lin et al 34 also observed that loading less than 0.05 wt% RuO2 on TiO2 gave much higher activity toward the photocatalytic oxidation of sulfur-containing organic compounds and dyes. Sakata et al 19 claimed that so small an amount of RuO2, approximately 0.03 monolayer, on bulk TiO2 surface (particle size of 0.2-0.4 m, surface area of 10 m 2 g -1 )…”

“…The formation of a heterojunction at the RuO2-TiO2 interface, band gap narrowing, and upward band bending at the interface effectively promote the separation of photoinduced electrons and holes, leading to an increase in photocatalytic H2 evolution. RuO2 via an intimate contact due to higher work function of RuO2, 19,21,35 subsequently reacting with protons, water and methanol. The photoinduced holes from VB of TiO2 NRs are irreversibly scavenged by methanol to produce various oxidation intermediates and products such as  OH radical,  CH2OH, HCHO, HCOOH and CO2.…”

“…3,6,[18][19][20][21] Recently, a first attempt toward H2 production from water under UV excitation over RuO2/anatase-TiO2 nanocomposites was conducted, where an upward band bending at the RuO2-TiO2 interface has been proposed to explain the good performance of H2 evolution. 21 In addition, density functional calculations performed on RuO2/TiO2(110)…”

The Synergistic Effects of Two Co-catalysts on Zn2GeO4 on Photocatalytic Water Splitting

“…In the case of water splitting, RuO 2 has been demonstrated to be an effective oxidation catalyst for O 2 evolution [31][32][33][34]. At the same time, some researchers considered that RuO 2 acts as a reduction catalyst for H 2 evolution [35]. Though RuO 2 has been examined as a co-catalyst for overall water splitting, the role of RuO 2 has not been clearly clarified.…”

Inhibition of corrosion of mild steel in well water by TiO2 nanoparticles and an aqueous extract of May flower

“…Copper nanoparticles have improved the corrosion inhibition efficiency of carbon steel. Titanium dioxide (TiO 2 ) is a very promising metal oxide which has been widely studied as a photocatalyst for organic synthesis [12] and environmental cleaning processes [13]. Recent applications, based on the photocatalysis and photoactivity of TiO 2 , include antifouling, antibacterial, deodorizing and self-cleaning functions [14].…”