摘要： Heterostructure composites are promising materials in photocatalytic hydrogen evolution due to their advantage on promoting photogenerated carrier separation efficiently. However, the weak interfacial interaction can block electron transfer and complicate synthesis methods restrict the practical application of catalysts. Here, we report an interfacial enhanced amorphous porous NbOx(OH)y/g-C3N4 heterostructure composite through a spontaneous coupling process. It was characterized by XRD, TEM, FT-IR, XPS, NH3-TPD and CO2-TPD, etc., which demonstrated that NbOx(OH)y possess amorphous porous structures with high specific surface area (205 m2/g) and plenty of acidic sites (418 μmol/g) as well as basic sites (184 μmol/g) contributed from uncoordinated Nb and -OH. These acidic and basic sites electrostatically attract -NHx and C-OH on the surface of g-C3N4 to form hydrogen bonds (Nb-O-H???NH2, Nb-O???H-O-C), showing a strong electron interaction between NbOx(OH)y and g-C3N4. When tested as a photocatalyst for water splitting under visible light, the optimal NbOx(OH)y/CN-0.05 heterostructure composite exhibits a hydrogen evolution rate of 53 μmol/g/h, which is about 14 times higher than that of g-C3N4 (3.8 μmol/g/h) and is even superior than P25 (16 μmol/g/h). These present findings lay a foundation for the synthesis of strongly interacting heterogeneous composites.