Crafting Mussel-Inspired Metal Nanoparticle-Decorated Ultrathin Graphitic Carbon Nitride for the Degradation of Chemical Pollutants and Production of Chemical Resources

The development of efficient photocatalysts for the degradation of organic pollutants and production of hydrogen peroxide (H ₂ O ₂ ) is an attractive two-in-one strategy to address environmental remediation concerns and chemical resource demands. Graphitic carbon nitride (g-C ₃ N ₄ ) possesses unique electronic and optical properties. However, bulk g-C ₃ N ₄ suffers from inefficient sunlight absorption and low carrier mobility. Once exfoliated, ultrathin nanosheets of g-C ₃ N ₄ attain much intriguing photocatalytic activity. Herein, a mussel-inspired strategy is developed to yield silver-decorated ultrathin g-C ₃ N ₄ nanosheets (Ag@U-g-C ₃ N ₄ -NS). The optimum Ag@U-g-C ₃ N ₄ -NS photocatalyst exhibits enhanced electrochemical properties and excellent performance for the degradation of organic pollutants. Due to the photoformed valence band holes and selective two-electron reduction of O ₂ by the conduction band electrons, it also renders an efficient, economic, and green route to light-driven H ₂ O ₂ production with an initial rate of 0.75 × 10 ⁻⁶ m min ⁻¹ . The improved photocatalytic performance is primarily attributed to the large specific surface area of the U-g-C ₃ N ₄ -NS layer, the surface plasmon resonance effect induced by Ag nanoparticles, and the cooperative electronic capture properties between Ag and U-g-C ₃ N ₄ -NS. Consequently, this unique photocatalyst possesses the extended absorption region, which effectively suppresses the recombination of electron–hole pairs and facilitates the transfer of electrons to participate in photocatalytic reactions.