The novel ternary Fe3N/Fe2O3/C3N4 photocatalyst was prepared by thermal pyrolysis of potassium ferricyanide in melamine. The structural, morphological and physico-chemical properties of the photocatalyst were characterized by a multi-technique approach. Photocatalytic experiments supported that 0.04 g of the photocatalyst was able to totally remove 5 ppm of rhodamine B (RhB) solution under acidic condition with the rate constant of 0.1 min−1 in less than 30 min. According to spin-trapping ESR analysis, •OH radicals play a key role in the RhB photodegradation implying Z-scheme mechanism is applicable to our system. Moreover, the evolution rate of CO and CH4 over the photocatalyst was 8.03 and 1.6 μmol g−1 h−1, respectively, which was much higher than the reference photocatalysts under the same conditions. The enhanced photocatalytic performance of this system is attributed to the unique ternary heterojunction between the interfaces of g-C3N4, Fe3N and Fe2O3, which effectively suppressed the charge carriers recombination. Display omitted •A novel ternary Fe3N/Fe2O3/C3N4 photocatalyst was prepared from cheap raw materials.•The interfacial Fe3N regions act as electron mediator and bandgap modifier.•The mechanism of RhB photodegradation was well discussed based on EPR experiments.•The ternary Fe3N/Fe2O3/C3N4 photocatalyst showed efficient photocatalytic CH4 evolution performance.