TY - GEN A1 - Cibrev, Dejan A1 - Tallarida, Massimo A1 - Das, Chittaranjan A1 - Lana-Villarreal, Teresa A1 - Schmeißer, Dieter A1 - Gómez, Roberto T1 - New insights into water photooxidation on reductively pretreated hematite photoanodes T2 - Physical Chemistry Chemical Physics N2 - It has been recently demonstrated that the photoactivity toward oxygen evolution of a number of n-type metal oxides can be substantially improved by a reductive electrochemical pretreatment. Such an enhancement has been primarily linked to the formation of low valent metal species that increase electrode conductivity. In this work, we report new insights into the electrochemical doping using highly ordered (110)-oriented hematite nanorods directly grown on FTO. The reductive pretreatment consists in applying negative potentials for a controlled period of time. Such a pretreatment was optimized in both potentiostatic and potentiodynamic regimes. We show that the optimized pretreatment enhances electrode conductivity due to an increase in charge carrier density. However, it additionally triggers changes in the morphologic, catalytic and electronic properties that facilitate the separation and collection of the photogenerated charge carriers causing an up to 8-fold enhancement in the photocurrent for water oxidation. The reductive pretreatment can be considered as a highly controllable electrochemical n-type doping with the amount of generated Fe2+/polaron species and the change in film morphology as the main factors determining the final efficiency for water photooxidation of the resulting electrodes. KW - hematite KW - photoanode KW - water oxidation KW - water splitting Y1 - 2017 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/20247 SN - 1463-9076 SN - 1463-9084 VL - 19 IS - 32 SP - 21807 EP - 21817 ER -