The main existing issues in graphitic carbon nitride (g-C₃N₄) based photocatalytic hydrogen (H₂) production include poor separation and transfer of photogenerated charge carriers and low optical absorption. Thus, the construction of a multicomponent co-catalyst and its integration with g-C₃N₄ to facilitate the transport and separation of photoexcited charge carriers are regarded as a promising approach for augmenting the photocatalytic H₂ production activity. In this study, we report CoZnS@NSC-X/g-C₃N₄ (where X indicates sulfidation times of 15, 30, 45, and 60 min) nanocomposites constructed from a CoZn-MOF derived CoS₂, Co₃S₄ and ZnS intercalated nitrogen/sulfur-doped carbon (CoZnS@NSC) nanoparticle co-catalyst and g-C₃N₄ for H₂ production from water splitting. The maximum photocatalytic H₂ evolution rate (610.8 μmol h⁻¹ g⁻¹) of the CoZnS@NSC-15/g-C₃N₄ heterostructure, with an optimized CoZnS@NSC loading of 10 wt% and 15 min sulfidation, is nearly 3.7 and 290.9 times higher than those of unsulfidated CoZn@NC/g-C₃N₄ and bare g-C₃N₄, respectively. This significantly boosted photocatalytic performance is attributed to the efficient separation and transfer of electron–hole (e⁻/h⁺) pairs and electronic conductivity caused by the appropriate sulfidation time and loading amount of CoZnS@NSC nanoparticles. This work offers a facile approach to designing metal–organic framework derived co-catalyst modified semiconductor-based photocatalysts for high-performance in practical applications.