How Gold Deposition Affects Anatase Performance in the Photo-catalytic Oxidation of Cyclohexane

Abstract

Gold deposition on Hombikat UV100 was found to negatively affect the activity of this Anatase catalyst in selective photo-oxidation of cyclohexane. By ammonia TPD and DRIFT spectroscopy it was determined that the Au deposition procedure leads to a significant decrease in OH-group density (mol m -2 BET ) on Hombikat, suggesting that the amount of surface OH-groups, rather than the presence or absence of Au, is determining the catalytic performance. The importance of surface OH-groups was demonstrated by comparing the performance of Hombikat (with and without Au deposition) to surface propoxylated TiO 2 , synthesized by a sol-gel method from titanium (IV) isopropoxide. The effect of the deposition recipe of noble metals on the surface composition of TiO 2 should thus be taken into account in evaluating and explaining photocatalytic performance of TiO 2 modified by noble metals (Au), in particular in non-aqueous phase reactions.

Sustainable Carbon Dioxide Photoreduction by a Cooperative Effect of Reactor Design and Titania Metal Promotion

“…The catalytic data indicate that the introduction of gold nanoparticles on the TiO2 surface seems to increase the hydrophilicity of the photocatalyst and, as a consequence, the capability of Au-TiO2 to adsorb CO2 was diminished. Carneiro et al reported that gold nanoparticles are able to modify hydroxyl group's population on titania [88]. Hence, it can be proposed that the different surface properties of CuO-TiO2 and Au-TiO2 play a key role in the reaction, as revealed by the different photocatalytic behaviour displayed by the two photocatalysts.…”

Effects of Au Loading and CO2 Addition on Photocatalytic Selective Phenol Oxidation over TiO2‐Supported Au Nanoparticles

“…On the other hand, Au/TiO 2 shows higher UV light‐induced activity than that of pristine TiO 2 , primarily because of the increase in the charge separation efficiency by the interfacial electron transfer from TiO 2 to Au 22. 23 However, there are recent reports describing that Au nanoparticle loading can decrease the photocatalytic activity of TiO 2 under visible24 and UV light irradiation 25. 26 Moreover, the UV light‐induced photocatalytic activity of Au nanoparticles due to the interband transition has also been reported 19.…”

Heteronanostructure of Ag particle on titanate nanowire membrane with enhanced photocatalytic properties and bactericidal activities

“…One is to prepare small TiO 2 particles with a very large surface area, which can exhibit superior performance over bulk materials [16]. The other is to modify the band gap of TiO 2 by doping other elements [17][18][19], sensitizing with dyes [20][21][22], and grafting heteronanostructure [23,24]. Especially, metal-semiconductor heteronanostructure as an effective photocatalysis has attracted great attention for air and water purification due to the strong oxidizing properties and stability under UV irradiation [24][25][26].…”