TiN anchored mesoporous single-crystalline LaTiO2N with ohmic contact to expedite photocarrier separation for efficient photocatalytic water splitting

LaTiO 2 N is a promising photocatalyst for solar water splitting but is generally subject to a low activity due to inadequate separation of photocarriers (i.e . e - and h + ). Loading noble metal cocatalysts such as Pt often has limited improvements because of their Schottky-type interfaces with LaTiO 2 N, resulting in a deficient electron collection at the surface catalytic sites. In this work, TiN nanoparticles have been firmly anchored at the surface of mesoporous single-crystalline LaTiO 2 N. As opposed to Pt, TiN has an ohmic contact with LaTiO 2 N due to a comparable work function and the structurally matched heterointerfaces. Such a tight and ohmic connection enables TiN to readily collect electrons from LaTiO 2 N, which in turn substantially improves the photocarrier separation and photocatalytic activity. These findings justify that TiN is an ideal relay for electron transfer between n-type semiconductors and noble metal cocatalysts which would otherwise be very difficult when the Schottky-type interfaces are formed.