g-C3N4 has been used as a photocatalyst to overcome the issues of environmental crises and energy shortages. Here, red g-C3N4 nanosheets (Eg: ∼ 1.89 eV) were used as seeds for the edge-epitaxial growth of yellow g-C3N4 (Eg: ∼ 2.59 eV) to form type II heterostructures. The heterostructures revealed superior photocatalytic activity for enhanced H2 (3996 μmol g-1 h-1), CO (3.8 μmol g-1 h-1), and CH4 (1.8 μmol g-1 h-1) evolution.