Critical review: The photoreaction of TiO2 and Au/TiO2 single crystal and powder surfaces with organic adsorbates. Emphasis on hydrogen production from renewables

14 Dec 2011

In this critical review, Karen Connelly and Hicham Idriss from the University of Aberdeen, UK and SABIC T&I, Saudi Aradia, review the fundamental aspects behind the reactivity of TiO₂ surfaces.

The authors look at both rutile-TiO₂and a gold/TiO₂system and the various factors that affect their reactivity, before studying the photoreaction of ethanol in more detail. Here, they show that the gold/TiO₂system shows about two orders of magnitude high activity that rutile-TiO₂and discuss the mechanisms of hydrogen production. However, the authors highlight that further work is still needed in this field as only one third of the hydrogen is extracted from the ethanol. They highlight that the challenge will be in designing photocatalysts for hydrogen production that are capable of breaking carbon-carbon bonds under ambient conditions.