The support characteristics under polyamide thin films have proven significant impact on the performance of nanofiltration thin film composite (TFC) membranes. In this study, polyethersulphone (PES) support was initially furnished with an interphase layer of different graphitic carbon nitride derivatives and nanocomposites (g-C3N4, oxidized g-C3N4, and g-C3N4/CuFe2O4) to improve the specifications of TFC membranes. Then, the polyamide layer was fabricated by interfacial polymerization on top of the interphase layer. The interlayer helped fine-tune the thickness and surface characteristics such as roughness, wettability, and zeta potential of the polyamide layer, in the way of improving the separation and antifouling capabilities of the TFC membranes. The interlayered thin film nanocomposite (ITFN) membranes considerably indicated better water permeability and rejection of methylene blue (MB), methyl orange (MO), Cadmium nitrate, and sodium sulfate (Na2SO4). We showed that ITFNs loaded with 0.01 wt% g-C3N4/CuFe2O4 had a permeability of ~9.2 LMH/bar, upper from ~3.8 LMH/bar in the pristine form, exhibiting outstanding water flux. The rejection data showed nearly two-fold increase of rejection of Cadmium nitrate, sodium sulfate, and dyes rather than the pristine nanofiltration membrane. The modified nanofiltration membranes remarkably exhibited better antifouling properties and higher flux recovery ratios as well.