Presently, among the known 2D carbon-based materials, g-C3N4 have the highest N content and highly stable in acidic or alkaline environments. Being a semiconducting material, g-C3N4 can respond well to light, and affords viable openings for photo-enhanced electrochemistry for energy storage and conversion. Based on these, recent research is focused on g-C3N4 nanosheets for applications in both energy conversion and storage.