Herein, graphitic carbon nitride (g-C3N4)as a novel thermo-driven catalyst was used for catalytic decomposition of organic dyes with the assistance of H2O2. In comparison with the experiment with individual catalyst or H2O2, a prominent enhancement of performance was achieved by the synergetic effect of g-C3N4 and H2O2. Experimental parameters like the H2O2 dosage and reaction temperature were optimized, and the catalyst exhibited excellent application universality for various concentration and different dyes. By physicochemical characterizations, the modification or doping with oxygen-containing groups on carbon nitride framework was demonstrated. We proposed a possible mechanism that the doping level trapped thermo-excited electrons to promote the separation of electrons and holes. On the other hand H2O2 was reduced by the excited electron to produce hydroxyl radical. The quenching experiment suggested the holes and hydroxyl radical were the main active species, thus verifying the synergetic effect of g-C3N4 and H2O2. Additionally, the superior stability and reusability were also proved by the successive five cycles, where the activity was even gradually improved with the increase of cycle number. (C) 2016 Elsevier B.V. All rights reserved.