LaCl3 flux mediated Ta3N5 planar photoanode for solar water oxidation

Ta 3 N 5 is a promising candidate for photoelectrochemical (PEC) water splitting. Recently gratifying photocurrents have been reported through various advanced techniques. However, obtaining high performance Ta 3 N 5 photoanode prepared by direct oxidation and nitridation remains challenging. In this work, efficient Ta 3 N 5 photoanode was fabricated on Ta foil by direct oxidation and nitridation method with LaCl 3 flux mediated treatment. The highest photoresponse (8.2 mA cm −2 @ 1.23 V RHE ) for direct oxidized and nitrided Ta 3 N 5 is achieved with the help of LaCl 3 flux, which is nearly doubled compared to the untreated counterparts. Theoretical analysis suggests an interfacial charge transfer in LaTaON 2 /Ta 3 N 5 heterostructure and significant increase in carrier concentration on La doped Ta 3 N 5 surface. The introduction of LaCl 3 flux brings a new look to this traditional method and it may potentially be applied to large area and low cost photoanodes.