LAUSR

A NiO/CeO2p–n heterojunction with the hierarchically porous microspheres was fabricated by annealing the precursor of the nickel/cerium mixed-metal metal–organic frameworks. The morphologies, microstructures, composition, specific surface area, photogenerated electron–hole pair separation/transfer, and photocatalytic activities were characterized for all acquired catalysts. The photodegradation rates of organic dyes including methyl orange and methylene blue were investigated under ultraviolet light. The NiO/CeO2 heterojunctions showed a much higher photocatalytic performance than that of pure NiO and CeO2. Among all photocatalysts NiO/CeO2-3 presented the best photocatalytic activity, i.e., the degradation of MO was 2.6 times higher than pure NiO under ultraviolet light, and the hydrogen generation with the rate of about 29.6 μmol h−1 g−1. The improved photocatalytic performance could be ascribed to the formation of the NiO/CeO2p–n heterojunction, which is beneficial for effective separation and fast transfer of the photoexcited electron–hole pairs.