Heterojunction Synergies in Titania‐Supported Gold Photocatalysts: Implications for Solar Hydrogen Production. Issue 15 (24th June 2015)

• Record Type: Journal Article
• Authors: Jovic, Vedran; Smith, Kevin E.; Idriss, Hicham; Waterhouse, Geoffrey I. N.
• Is Part Of: ChemSusChem. Volume 8:Issue 15(2015:Aug.)
• Page Start: 2551
• Page End: 2559
• Publication Date: 2015-06-24
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201500126
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The mixed‐phase nature of P25 TiO₂ (85 % anatase/15 % rutile) plays a key role in the high H₂ production rates shown by Au/P25 TiO₂ photocatalysts in alcohol/water systems. However, a full understanding of the synergistic charge transfer mechanisms between the TiO₂ polymorphs that drive the high rates is yet to be realised. Here, we deconstruct P25 TiO₂ into its component phases, functionalise the phases with Au nanoparticles and explore charge transfer in Au/TiO₂ systems using EPR spectroscopy. EPR spectroscopy and photocatalytic data provide direct evidence that electrons excited across the rutile band gap move to anatase lattice traps through interfacial surface sites, which decreases electron–hole pair recombination and increases charge carrier availability for photoreactions. In particular, three‐phase interfacial sites between Au, anatase and rutile appear to be H₂ evolution "hot spots". The results isolate the origin of high photocatalytic H₂ production rates seen in Au/P25 TiO₂ systems.</p> </abstract>