CeO2/TiO2 Heterojunction Nanotube Arrays for Highly Efficient Visible-Light Photoelectrochemical Water Splitting

Composite of rare earth oxides with TiO 2 nanotube arrays can effectively modify the photoelectrochemical (PEC) behavior of TiO 2 . A CeO 2 /TiO 2 heterojunction was prepared by loading CeO 2 nanoparticles on anodized TiO 2 nanotube (TNT) arrays for PEC water splitting. The CeO 2 /TNT electrode exhibited a high photocurrent density of 2.11 mA·cm –2, 4.3 times that of pure TNT (0.49 mA·cm –2 ) at 1.23 V vs RHE under AM 1.5G light. And CeO 2 /TNT realized a high PEC H 2 evolution rate of 17.86 μmol/h, 4.5 times that of pure TNT at 1.55 V vs RHE. The effective performance of the CeO 2 /TNT electrode could be attributed to its reasonable band gap structure facilitating visible light absorption and efficient charge transfer, inhibiting the recombination of electron/hole pairs. This work confirms the successful construction of CeO 2 /TiO 2 heterojunction on TNT arrays for improving the PEC performance of TiO 2 for H 2 production.