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

Abstract Four photocatalysts solids were designed using a new Pd−Te complex, [Pd 2 (μ‐TePh) 2 (bipy) 2 ](PF 6 ) 2 , immobilized over titania to improve its solar energy harvesting ability for enhancing H 2 production by water splitting under sunlight (300 W Xe/Hg lamp). Firstly, the photocatalytic performance for H 2 production of the porous TiO 2 supports (m‐TiO 2 ), 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‐TiO 2 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‐TiO 2 showed the greatest hydrogen production (3631 μmol g −1 h −1 ), which is 69 times greater than that of the pure m‐TiO 2 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‐TiO 2 , 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 H 2 production by water splitting under sunlight.