Au/TiO₂–gC₃N₄ Nanocomposites for Enhanced Photocatalytic H₂ Production from Water under Visible Light Irradiation with Very Low Quantities of Sacrificial Agents

Here for the first time the design and optimization are presented of a three‐component Au/TiO 2 –gC 3 N 4 nanocomposite photocatalyst able to efficiently produce H 2 from water using very low amounts of sacrificial agents and under visible light irradiation. This enhanced photocatalytic behavior compared to Au/TiO 2 and Au/gC 3 N 4 materials is the result of synergetic effects due to high quality assembly and interface between the three components. This optimized nanoscale assembly characterized by simultaneous favorable nanoheterojunction formation between g‐C 3 N 4 and TiO 2 semiconductors, as well as AuNPs/gC 3 N 4 and AuNPs/TiO 2 junctions, leads to enhanced visible light harvesting, charge separation, and H 2 production. This composite photocatalyst yields a high H 2 production (350 µmol −1 h −1 g catalyst −1 ) under visible light irradiation with minimal amounts of sacrificial agent (≤1 vol%), corresponding to activities much higher than reported so far under comparable conditions.