Effect of TiO2 polymorph and alcohol sacrificial agent on the activity of Au/TiO2 photocatalysts for H2 production in alcohol–water mixtures

Evidence of Plasmonic Induced Photocatalytic Hydrogen Production on Pd/TiO2 Upon Deposition on Thin Films of Gold

“…external diameter) at 45 •C and N 2 was used as a carrier gas (Flow rate of 20mL/min). We, and others, have studied the reaction products during photocatalytic reforming of alcohols which ultimately results in hydrogen and CO 2 formation as the final reaction products [10][11][12][13][14][15].…”

Operational Conditions Affecting Hydrogen Production by the Photoreforming of Organic Compounds using Titania Nanoparticles with Gold

“…The relevant redox potential level of the acceptor species is thermodynamically required to be below (more positive than) the bottom of the conduction band of the semiconductor. The redox potential level of the donor species needs to be above (more negative than) the top of the valence band of the semiconductor to donate an electron to the vacant hole . TiO 2 has received much attention because it accomplishes this requirement for water splitting and the photoreforming of several organic compounds.…”

“…Here, the Au loading on a semiconductor surface under UV light acts as an electron sink, which shows the movement of the Fermi level towards a more negative direction, at approximately −0.27 eV, between the bottom of the TiO 2 conduction band and the H + /H 2 redox couple, which is a key factor for increasing the Schottky barrier effect . Thereby, electrons photoexcited into the conduction band of TiO 2 migrate onto the supported Au NPs, which suppresses electron–hole pair recombination in TiO 2 , and the metal NPs themselves function as active surface sites for hydrogen evolution . However, holes migrate to the surface upon which they oxidize the adsorbed molecules …”

“…Recent studies emphasize the influence of the physical properties of the alcohols on the hydrogen productivity, such as polarity and redox potential. Polarity is critical to the interaction of the alcohol with the TiO 2 surface, and high‐polarity alcohols will interact strongly with the semiconductor surface, resulting in the injection of more electrons into the TiO 2 valence band, and the larger the potential separation between the alcohol oxidation potential and the TiO 2 valence band, the higher the hydrogen production rate …”

“…The lack of comprehensive studies in which the effect of changes to low concentrations of NPs on the hydrogen production rates in TiO 2 –Au systems are examined simultaneously is a gap in the current literature. Moreover, it is unclear whether the relative activities of photocatalysts are altered by the type of alcohol hole scavenger used in the photocatalytic tests . Therefore, in this work, methanol and ethanol are compared as sacrificial agents for the oxidative half‐reaction and Au is examined as a cocatalyst for the hydrogen‐reduction reaction .…”