Photocatalytic Efficiency Improvement of Porous TiO2 Immobilized by a Pd‐Te Complex for H2 Production by Water Splitting

Four photocatalysts solids were designed using a new Pd‐Te complex, [Pd2(μ‐TePh)2(bipy)2](PF6)2, immobilized over titania to improve its solar energy harvesting ability for enhancing H2 production by water splitting under sunlight (300 W Xe/Hg lamp). Firstly, the photocatalytic performance for H2 production of the porous TiO2 supports (m‐TiO2), synthesized with varying textural properties and anatase/rutile contents, were compared. Furthermore, cyclic voltammetry measurements revealed that the Pd‐Te complex can catalyze protons to hydrogen under weak acidic conditions. Then, different wt% concentrations of the complex were immobilized over the m‐TiO2 of the greatest performance and also over Degussa P25 (commercial titania) for photocatalytic comparison. Among the newly designed photocatalysts, the one containing only 4 wt% of Pd‐Te complex over m‐TiO2 showed the greatest hydrogen production (3631 μmol g‐1 h‐1), which is 69 times greater than that of the pure m‐TiO2 and 378 times higher than that of the pure Pd‐Te complex. These results suggested the crucial role of the Pd‐Te complex when combined with m‐TiO2, promoting greater photocatalytic performance compared to the pure support. This outcome inspires an extensive investigation of metal complexes combined with semiconductors to improve their ability for photocatalytic H2 production by water splitting under sunlight.