We report on H₂ generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO_2−xN_x (Au-NT) nanocomposites. Solar H₂ generation (1.5 mmol h⁻¹ g⁻¹) from aqueous methanol has been demonstrated with Au-NT nanocomposites. The water splitting activity of Au-NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron-injection efficiency from nano-Au to the conduction band of TiO₂, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au-NT that highlights the energy transfer from nano-Au to TiO₂. The p–n heterojunction observed between the Au (0 0 1) and TiO₂ (1 0 1) facets helps towards the higher charge separation and their utilization. A low mesochannel depth (<10 nm) associated with disordered mesoporous TiO_2−xN_x helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible-light absorption, as a result of the surface plasmon resonance of nano-Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible-light photons. Finally, electronically integrated nano-Au with TiO_2−xN_x in Au-NT is evident from Raman and X-ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H₂ production. It is likely that a higher rate of H₂ production than that reported here is feasible by strategically locating Au clusters in porous TiO₂ to generate hot spots through electronic integration.