In Situ Generation of Copper Species Nanocrystals in TiO₂ Electrospun Nanofibers: A Multi-hetero-junction Photocatalyst for Highly Efficient Water Reduction

Engineering the multi-hetero-junctions in semiconductor photocatalysts has been recognized as a promising way to achieve highly efficient photocatalytic solar-fuel generation, because the photoinduced heterointerfacial charge transfer can greatly hinder the recombination process of charge-carrier in photocatalysts. In this work, we fabricated copper species nanocrystals/TiO₂ multi-hetero-junction photocatalysts through in situ reduction of CuO nanocrystals in CuO/TiO₂ electrospun nanofibers by a hydrothermal method assisted by glucose. By changing the concentration of glucose, the composition ratio of copper species nanocrystals, including CuO, Cu₂O, and Cu, can be adjusted in multi-hetero-junction nanofibers. Upon simulated sunlight irradiation, the optimal copper species nanocrystals/TiO₂ multi-hetero-junction nanofibers exhibited an H₂ evolution rate of ∼10.04 μmol h^–1, a 17.3 times increase over that of bare TiO₂ nanofibers (∼0.57 μmol h^–1)