A morphology effect of hematite photoanode for photoelectrochemical water oxidation

Hematite has been a popular photoanode for photoelectrochemical water splitting; however, its performance varies widely in the literature. In-depth understanding of the structure-performance relationship of hematite photoanode is still lacking. Here, we report a finding that without the use of co-catalysts or any alteration in crystal structure, the performance of hematite photoanode can be markedly improved by properly enlarging the space among alpha-Fe2O3 nano-crystalline, i.e., by increasing the pore size in the electrode. Such a finding indicates that in addition to the known catalytic and crystal effects, the internal structure of the hematite electrode is also a very sensitive factor to PEC efficiency.