The rational design of 2D hybrid materials has gained substantial attention in the field of membrane-based water treatment. In this study, a hierarchical flower-like MoS2/g-C3N4 (Hf-MoCN) hybrid has been reported as a modifier for antifouling and performance enhancement of polysulfone (PSF) membranes. PSF membranes modified with 0.1, 0.3, and 0.5 wt% of Hf-MoCN were prepared by phase inversion technique. The prepared membranes were examined for their morphology, contact angle, pore size, and porosity. Further, the ultrafiltration performance and antifouling ability of the PSF/ Hf-MoCN were examined through BSA filtration studies. The contact angle dropped from 78° to 55° when 0.3 wt% of Hf-MoCN was incorporated into the PSF matrix. Moreover, the pure water and BSA fluxes of this modified membrane were improved by 2.1 and 3.6 folds, respectively, compared to the bare membrane. Besides, all Hf-MoCN modified membranes showed higher BSA rejection efficiency than the unmodified membrane. Flux recovery ratio studies showed that the membrane modified with 0.3 wt% of Hf-MoCN had better antifouling ability than the other membranes. Thus, the study showed that the incorporation of Hf-MoCN provided the membrane with a versatile transport pathway and desirable surface properties, thus improving its wettability, filtration performance and antifouling ability.