METHOD FOR PRODUCING PHOTOELECTRODE
A photoelectrode ( 100 ) of the present invention includes a conductive layer ( 12 ) and a photocatalytic layer ( 13 ) provided on the conductive layer ( 12 ). The conductive layer ( 12 ) is made of a metal nitride. The photocatalytic layer ( 13 ) is made of at least one selected from the group consisting of a nitride semiconductor and an oxynitride semiconductor. When the photocatalytic layer ( 13 ) is made of a n-type semiconductor, the energy difference between the vacuum level and the Fermi level of the conductive layer ( 12 ) is smaller than the energy difference between the vacuum level and the Fermi level of the photocatalytic layer ( 13 ). When the photocatalytic layer ( 13 ) is made of a p-type semiconductor, the energy difference between the vacuum level and the Fermi level of the conductive layer ( 12 ) is larger than the energy difference between the vacuum level and the Fermi level of the photocatalytic layer ( 13 ).
1 - 6 . (canceled)
7 . A method for producing a photoelectrode having a conductive layer and a photocatalytic layer provided on the conductive layer, the method comprising the steps of:
forming a metal nitride film serving as the conductive layer on a substrate;
forming a metal oxide film on the metal nitride film; and
subjecting the metal oxide film to nitriding treatment to form the photocatalytic layer.
8 . The method for producing a photoelectrode according to claim 7 , wherein the nitriding treatment is performed by reacting the metal oxide film with ammonia gas.
9 . The method for producing a photoelectrode according to claim 7 , further comprising a step of removing the substrate.
10 . The method for producing a photoelectrode according to claim 7 , wherein the metal oxide film is at least one selected from the group consisting of a film of an oxide containing a tantalum element, a film of an oxide containing a niobium element, and a film of an oxide containing a titanium element.
11 . (canceled)