Photoelectrochemical and crystalline properties of a GaN photoelectrode loaded with α-Fe(2)O(3) as cocatalyst

Nitrides are of particular interest in energy applications given their suitability to photocatalytically generate H(2) from aqueous solutions. However, one of the drawbacks of nitrides is the decomposition they suffer when used in photoelectrochemical cells. Here, we report the improvement of the catalytic performance and chemical stability of a GaN electrode when it is decorated with Fe(2)O(3) particles compared with an undecorated electrode. Our results show a higher reaction rate in the Fe(2)O(3)/GaN electrode, and that photocorrosion marks take more than 20 times longer to appear on it. We also characterized the crystalline properties of the Fe(2)O(3) particles with transmission electron microscopy. The results show that the Fe(2)O(3) particles keep an epitaxial relationship with GaN that follows the Fe(2)O(3)[Formula: see text] GaN[Formula: see text] and Fe(2)O(3)[Formula: see text] GaN[Formula: see text] symmetry constraints. We also characterized an Fe(2)O(3) (thin film)/GaN electrode, however it did not present any catalytic improvement compared with a bare GaN electrode. The epitaxial relationship found between the Fe(2)O(3) thin film and GaN exhibited the Fe(2)O(3)[Formula: see text] GaN[Formula: see text] and Fe(2)O(3)[Formula: see text] GaN[Formula: see text] symmetry constraints.