Our findings indicate a significant enhancement in the photocatalytic production of hydrogen peroxide when using Au NPs and TiO2 self-assembled into supraparticles. The enhancement in the H2O2 yield was found to increase with an increase in the supraparticle size. The supraparticle size could be conveniently controlled through the ratio of TiO2 precursor and PAH-covered Au NPs, by regulating their electrostatic interaction and as such facilitate their self-assembly into micron-sized aggregates. Using SERS and EELS it was shown that the near-field enhancement increases the local electromagnetic field between Au nanoparticles and around the TiO2, thus drastically improving light absorption through plasmonic coupling within the supraparticles. In addition, EPR spectroscopy and radical quenching experiments were conducted, indicating that under conditions of simultaneous excitation by UV and visible light at the plasmon resonance frequency, the enhanced photocatalytic activity is dominated by electron-mediated reactions, confirming the role of electron-mediated oxygen reduction pathways as major route towards improved photocatalytic H2O2 production in the present system. These results not only demonstrate the potential of Au-TiO2 supraparticles in plasmon-enhanced photocatalytic H2O2