High temperature activation of hematite nanorods for sunlight driven water oxidation reaction

作者：Ito Nathalie Minko; Carvalho Waldemir Moura Jr; Muche Dereck Nills Ferreira; Castro Ricardo Hauch Ribeiro; Dalpian Gustavo Martini; Souza Flavio Leandro^*

来源：Physical Chemistry Chemical Physics, 2017, 19(36): 25025-25032.

DOI：10.1039/c7cp04827k

Here we show that chlorine species originating from commonly used iron precursors annihilate the hematite nanorod photocurrent by providing recombination pathways. Although hematite nanorod films could be obtained by thermal decomposition of the iron oxyhydroxide phase (beta-FeOOH), indistinguishable photocurrent responses under dark and sunlight irradiation conditions were observed until the nanorods were annealed (activated) at 750 degrees C. The annealing led to the elimination of observable chlorine species and allowed photocurrent responses of 1.3 mA cm(-2) at 1.23 V vs. RHE, which is comparable to the best results found in the literature, suggesting that residual chlorine species from the synthesis can act as electron traps and recombination sites for photogenerated holes.

• 出版日期2017-9-28