Résumé
Efficient hydrogen production by water photocatalysis requires effective charge separation and optimal reactant-catalyst interactions. However, producing catalysts with these features is still challenging. Here, electrospinning and calcination were used to fabricate zirconium (Zr)-doped TiO2 nanofibers with controlled crystalline phase. In all tested nanofiber samples (pure TiO2 and after doping with different Zr amounts), TiO2 was detected mainly in the anatase form. All nanofibers displayed high purity and crystallinity. Moreover, X-ray photoemission spectroscopy showed that Zr was present as Zr4 + ions on the TiO2 surface. The Zr-doped TiO2 nanofiber band gaps (determined with the Kubelka–Munk function) ranged from 3.00 eV to 3.2 eV (vs 3.09 for TiO2). The absorption of visible light was improved in Zr-doped TiO2 nanofibers because Zr addition led to the creation of intermediate electronic levels between the conduction and valence bands, and to the decrease of the electron recombination rate. Then, Zr doping effect on TiO2 electronic structure and photocatalytic properties was evaluated by density functional theory modeling. The nanofibers with 4 mol% of ZrOCl2⋅8 H2O exhibited the highest photocatalytic activity under visible light (hydrogen evolution rate of 2500 μmol⋅g⁻¹⋅h⁻¹, 23 times higher compared with pure TiO2 nanofibers). These one-dimensional nanostructures also showed excellent recyclability and sustained high photocatalytic efficiency, promising features for environmental and energy applications.