Layer‐by‐Layer Electrodeposition of FTO/TiO2/CuxO/CeO2 (1 <x< 2) Photocatalysts with High Peroxidase‐Like Activity by Greatly Enhanced Singlet Oxygen Generation

Abstract Inorganic nanomaterials have attracted much attention as enzyme mimics because of simple and stable spatial conformation of those artificially synthesized nanocatalysts. Cu 2 O, as an important kind of narrow band gap semiconductor, is identified as effective as visible‐light‐driven photocatalysts, which can catalyze decomposition of H 2 O 2 into reactive oxygen species. Moreover, after forming Cu x O/CeO 2 hybrids, the strongly coupled interface between the two components will further improve their catalytic performance. In this paper, the authors try to construct FTO/TiO 2 /Cu x O/CeO 2 (1 < x < 2) nanohybrids with such a kind of active interface via a layer‐by‐layer electrodeposition strategy by aid of the following surface etching process. It is found that FTO/TiO 2 /Cu x O/CeO 2 exhibits good peroxidase mimic activity in the dark but much better performance under visible light irradiation (λ ≥ 420 nm) during catalytic oxidation of 3,3′,5,5′‐tetramethylbenzidine substrates in the presence of H 2 O 2 . Detailed characterizations disclose that the construction of TiO 2 /Cu 2 O pn‐heterojunctions do effectively accelerate separation of photogenerated carriers, and the formation of a highly active Cu x O/CeO 2 interface is synergistically favorable for selectively generating singlet oxygen to boost the catalytic performance of FTO/TiO 2 /Cu x O/CeO 2 .