Enhanced Solar Hydrogen Evolution over In Situ Gold–Platinum Bimetallic Nanoparticle-Loaded Ti3+ Self-Doped Titania Photocatalysts

This work presents a photochemical and thermal treatment strategy to prepare in situ gold–platinum bimetallic nanoparticle-loaded titania photocatalysts with self-doped Ti 3+ states (Au–Pt/Ti 3+ nc-TiO 2 ). In situ loading of Au–Pt bimetallic nanoparticles and Ti 3+ self-doping in the TiO 2 crystal lattice result in excellent solar light photocatalytic activity. The Au–Pt/Ti 3+ nc-TiO 2 displays an improved hydrogen evolution rate (98.53 mmol h –1 g –1 ) when compared to in situ gold-loaded and in situ platinum-loaded titania (Au/Ti 3+ nc-TiO 2 and Pt/Ti 3+ nc-TiO 2, respectively) photocatalysts. The Au–Pt/Ti 3+ nc-TiO 2 photocatalyst is further restructured into titania inverse opal (Au–Pt/Ti 3+ io-TiO 2 ) photocatalyst by a facile colloidal photonic crystal (CPC) infiltration method. The Au–Pt/Ti 3+ io-TiO 2 photocatalyst displays a superior solar hydrogen evolution profile (181.77 mmol h –1 g –1 ) compared to all the other photocatalysts investigated for hydrogen production experiments, which makes them potential candidates for solar water splitting.