With photoconductor being transferred and separated, interface contact plays a crucial role in developing composites photocatalyst. In the present work, 2D crystalline g-C3N4 (called as CCN) with 2D TiO2 nanosheets (called as TO) obtained in situ oxidized single-layered Ti3C2Tx MXene is designed by an electrostatic self-assembly technology. This CCN/TO nanosheets system with a few TiO2 nanosheets distributed to the surface is not only prolonging lifetime of photoelectron but also stimulating photogenerated carriers transferred in contact interface. The electron transfer mechanism of CCN/TO is further proved by Pt photo-deposition method. Therein, the optimal CCN-TO-0.6 exhibits excellent performance of H2 generation compared with single photocatalyst of CCN. The result shows that the crystalline g-C3N4 photocatalysts introduced TiO2 with interfacial effect favorably reduce H+ to H2 and enhance photocatalytic activity.