Eosin Y-sensitized nanosheet-stacked hollow-sphere TiO₂ for efficient photocatalytic H₂ production under visible-light irradiation

Nanosheet (with around 20 nm in thickness)-stacked hollow-sphere TiO₂ was synthesized via a modified solvothermal reaction for different times followed by calcination treatment at different temperatures. After surface modification by different cations (H⁺ or Fe³⁺) and further sensitization by Eosin Y, the obtained photocatalysts achieved remarkably enhanced H₂-production activity (about 4.2 times of that for Eosin Y-sensitized P25) and stability under visible-light irradiation. The improved photocatalytic performance was synergistically caused by the enhanced Eosin Y sensitization (due to the enlarged surface area and electropositively modified surface), the optimized crystal structure (well-crystallized anatase phase), and the unique micro/nanostructure (nanosheet-stacked hollow spheres). This work presented an effective route to explore new visible-light-driven H₂-production photocatalysts by coupling nanomaterials with special morphologies and metal-free dyes with visible-light absorption.