Figure 2.

a) Galvanostatic profiles of 10 nm thick g‐C₃N₄ film at various areal current densities (0.013, 0.025, 0.051, 0.13, 0.25, 0.51 mA cm⁻²). b) Galvanostatic profiles of 150 nm thick g‐C₃N₄ film at various areal current densities (0.013, 0.051, 0.13, 0.25, 0.51 mA cm⁻²). Note: The capacity is calculated based on the film weight only. c) Comparison of the apparent capacities of 10 nm and 150 nm g‐C₃N₄ film on Cu foil at current density of 0.013 mA cm⁻². d) Long‐term cycling discharge capacities and coulombic efficiencies of 10 nm carbon nitride film at 0.25 mA cm⁻². e) Rate performance of the film at various areal current densities.