However, based on their sizes and resulting product formations, blue-emitting carbon nitride quantum dots appear to produce H2O following a four-electron pathway, making them optimal for fuel cell applications. Violet-emitting carbon nitride quantum dots follow a two-electron pathway to yield hydrogen peroxide (H2O2), a molecule with industrial significance in water treatment, disinfection, and cosmetic bleaching. The production of superoxide from greenemitting carbon nitride quantum dots follows a one-electron pathway to find utility in water purification, photodynamic cancer treatment, and organic synthesis.