In this manuscript, the effect of adding graphitic carbon nitride (g-C₃N₄) on the electrochemical prop- erties of ZnS conversion alloying anode has been investigated in detail. A cooperative phenomenon is observed in case of the ZnS/g-C₃N₄ composite anodes both in the lithium-ion and sodium-ion half-cell configuration. The ZnS nanoparticles render high capacity and gets lodged in the g-C₃N₄ nanosheets synthesized using acid assisted sonication method and leads to a synergistic effect which prevents restacking of layers and agglomeration of nanoparticles. The 0.7ZnS:0.3g-C₃N₄ composite delivers long term reversible capacity of ~596.9 mAh g⁻¹ after 1150 cycles and ~432.6 mAh g⁻¹ after 750 cycles in Li⁺/Na⁺ half-cell configuration, respectively, at a high current density of 1 A g⁻¹. The structural and electrochem- ical investigation of the bare ZnS and ZnS/g-C₃N₄ composite anodes along-with post-mortem SEM and TEM analysis has been discussed. The enhanced rate capability of the 0.7ZnS:0.3g-C₃N₄ electrode can be attributed to a fairly prominent role played by capacitive charge storage. The deleterious volume alter- ation effect during the shuttling of Li⁺/Na⁺ ions in ZnS is mitigated by the presence of g-C₃N₄ and it renders a high reversible capacity and initial coulombic efficiency to the composite anodes which has been studied via ex-situ X-ray photoelectron spectroscopy.