The development of efficient photocatalysts for the degradation of organic pollutants and production of hydrogen peroxide (H2 O2 ) is an attractive two-in-one strategy to address environmental remediation concerns and chemical resource demands. Graphitic carbon nitride (g-C3 N4 ) possesses unique electronic and optical properties. However, bulk g-C3 N4 suffers from inefficient sunlight absorption and low carrier mobility. Once exfoliated, ultrathin nanosheets of g-C3 N4 attain much intriguing photocatalytic activity. Herein, a mussel-inspired strategy is developed to yield silver-decorated ultrathin g-C3 N4 nanosheets (Ag@U-g-C3 N4 -NS). The optimum Ag@U-g-C3 N4 -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 O2 by the conduction band electrons, it also renders an efficient, economic, and green route to light-driven H2 O2 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-C3 N4 -NS layer, the surface plasmon resonance effect induced by Ag nanoparticles, and the cooperative electronic capture properties between Ag and U-g-C3 N4 -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.
Keywords: Ag nanoparticle; graphitic carbon nitride; hydrogen peroxide production; photocatalysis; polydopamine.
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