CeO₂/TiO₂ Heterojunction Nanotube\nArrays for Highly Efficient Visible-Light Photoelectrochemical Water\nSplitting

Abstract

Composite of rare earth oxides with\nTiO₂ nanotube arrays\ncan effectively modify the photoelectrochemical (PEC) behavior of\nTiO₂. A CeO₂/TiO₂ heterojunction\nwas prepared by loading CeO₂ nanoparticles on anodized\nTiO₂ nanotube (TNT) arrays for PEC water splitting. The\nCeO₂/TNT electrode exhibited a high photocurrent density\nof 2.11 mA·cm^–2, 4.3 times that of pure TNT\n(0.49 mA·cm^–2) at 1.23 V vs RHE under AM 1.5G\nlight. And CeO₂/TNT realized a high PEC H₂ evolution\nrate of 17.86 μmol/h, 4.5 times that of pure TNT at 1.55 V vs\nRHE. The effective performance of the CeO₂/TNT electrode\ncould be attributed to its reasonable band gap structure facilitating\nvisible light absorption and efficient charge transfer, inhibiting\nthe recombination of electron/hole pairs. This work confirms the successful\nconstruction of CeO₂/TiO₂ heterojunction on\nTNT arrays for improving the PEC performance of TiO₂ for\nH₂ production.