Preparation of amine functionalized g-C 3 N 4 @ H/S MOF NCs with visible light photocatalytic characteristic for 4-nitrophenol degradation from aqueous solution.

•g-C3N4-X@H/STi-MIL125-NH2 NCs were prepared via hydrothermal and ultrasound methods.•Sonochemical synthesis is a green and useful method to fabricate g-C3N4@Ti-MIL125-NH2 NCs.•The obtained NCs are characterized by FE-SEM, PXRD, FT-IR, UV–vis, PL, and EIS.•The degradation ability of g-C3N4@Ti-MIL125-NH2 NCs toward 4-nitrophenol was investigated.•g-C3N4-X@STi-MIL125-NH2 exhibits a higher efficiency than pure and g-C3N4, H/STi-MIL125-NH2, and g-C3N4-X@HTi-MIL125-NH2.