TiO₂@Layered Double Hydroxide Core–Shell Nanospheres with Largely Enhanced Photocatalytic Activity Toward O₂ Generation

Abstract

TiO 2 @CoAl‐layered double hydroxide (LDH) core–shell nanospheres are fabricated via hydrothermal synthesis of TiO 2 hollow nanospheres followed by in situ growth of CoAl‐LDH shell, which exhibit an extraordinarily high photocatalytic activity toward oxygen evolution from water oxidation. The O 2 generation rates of 2.34 and 2.24 mmol h −1 g −1 are achieved under full sunlight (>200 nm) and visible light (>420 nm), respectively, which are among the highest photocatalytic activities for oxygen production to date. The reason is attributed to the desirable incorporation of visible‐ light‐active LDH shell with UV light‐responsive TiO 2 core for promoted solar energy utilization. Most importantly, the combined experimental results and computational simulations reveal that the strong donor–acceptor coupling and suitable band matching between TiO 2 core and LDH shell facilitate the separation of photoinduced electron‐hole pairs, accounting for the highly efficient photocatalytic performance. Therefore, this work provides a facile and cost‐effective strategy for the design and fabrication of hierarchical semiconductor materials, which can be applied as photocatalyst toward water splitting and solar energy conversion.