We report a photocatalytic process for H2O2 synthesis by using 2-ethylanthraquinone (EAQ) as photo catalyst. H(2)EAQ (or HEAQ(center dot)) was in-situ produced by photocatalytic hydrogenation of EAQ with various solvents as hydrogen-donors (H-donors), and thus the pre-production of power-intensive H-2 was circumvented. The industrial hydrogenation of EAQ and the oxidation of H2EAQ with 02 here were combined into one pot for H2O2 photocatalytic production. EAQ molecule can be repeatedly used with high TON under both UV and visible light irradiation. When dual-phase reaction was adopted, the maximal H2O2 concentration of 574.0mM in aqueous phase was achieved with mesitylene as H-donor. As the produced H2O2 concentration in the industrial AO process is estimated as ca. 400 mM in one cycle, our method with the dual-phase reaction greatly promotes the possibility for the practical production of H2O2 with photocatalytic method. (C) 2016 Elsevier B.V. All rights reserved.