title: Charge carrier separation in nanostructured TiO2 photoelectrodes for water splitting.
abstract: There is intense interest in developing new novel nanostructured photoanodes for water splitting. It is therefore important that methods to analyze the effect of nanostructuring on water splitting yields are developed in order to rationalize the relative merits of this approach for different materials. In this study the dependence of charge separation efficiency (η(sep)) on potential during photoelectrochemical water splitting at pH 2 has been quantified in a model electrode system (nanocrystalline, mesoporous TiO2) using two independent methods. These are (i) analysis of incident photon conversion efficiency (IPCE) measurements and (ii) transient absorption (TA) spectroscopy measurements. The techniques provide good agreement with each other and show that a low maximum value of η(sep) (~0.18) is the primary cause of the low IPCE for water oxidation on these nc-TiO2 electrodes.
authors: Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK. a.j.cowan@liverpool.ac.uk
authors: Alexander J
authors: AJ
authors: Cowan
authors: Wenhua
authors: W
authors: Leng
authors: Piers R F
authors: PR
authors: Barnes
authors: David R
authors: DR
authors: Klug
authors: James R
authors: JR
authors: Durrant
mesh_terms: D004566:Electrodes; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; C009495:titanium dioxide; D014025:Titanium