Cobalt-Nickel Layered Double Hydroxides Modified on TiO Nanotube Arrays for Highly Efficient and Stable PEC Water Splitting.

TiO -based photoanodes have attracted extensive attention worldwide for photoelectrochemical (PEC) water splitting, but these materials still suffer from poor electron-hole separation and low photoconversion efficiency. Here, the high PEC water splitting activity and long-term stability against photocorrosion of well-aligned hierarchical TiO @CoNi-layered double hydroxides nanotube arrays (TiO @CoNi-LDHs NTAs) are reported. The typical TiO @CoNi-LDHs NTAs exhibits enhancing photocurrent density of 4.4 mA cm at a potential of 1.23 V (vs reversible hydrogen electrode) under AM 1.5G simulated sunlight (100 mW cm ), 3.3 times higher than that of the pristine TiO sample. Moreover, this hierarchical electrode displays excellent stability against photocorrosion with initial activity loss no more than 1.0% even after 10 h irradiation in Na SO electrolyte solution (pH 6.8), much competitive to those reported TiO -based photoelectrodes. This work may offer a combinatorial synthesis strategy for the preparation of hierarchical architectures with high PEC performances.