Fabrication of Heterostructured Fe 2 TiO 5 –TiO 2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion

Photocatalysts with well‐designed compositions and structures are desirable for achieving highly efficient solar‐to‐chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe 2 TiO 5 –TiO 2 nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL‐125(Ti) nanodisks (NDs) to Ti–Fe–O NCs, which are further converted to Fe 2 TiO 5 –TiO 2 NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe 2 TiO 5 –TiO 2 NCs show enhanced performance for PEC water oxidation compared with TiO 2 NDs, Fe 2 TiO 5 nanoparticles (NPs) and Fe 2 TiO 5 –TiO 2 NPs.