<i>In Situ</i> Ion Exchange Synthesis of Strongly Coupled Ag@AgCl/g‑C₃N₄ Porous Nanosheets as Plasmonic Photocatalyst for Highly Efficient Visible-Light Photocatalysis

A novel efficient Ag@AgCl/g-C₃N₄ plasmonic photocatalyst was synthesized by a rational <i>in situ</i> ion exchange approach between exfoliated g-C₃N₄ nanosheets with porous 2D morphology and AgNO₃. The as-prepared Ag@AgCl-9/g-C₃N₄ plasmonic photocatalyst exhibited excellent photocatalytic performance under visible light irradiation for rhodamine B degradation with a rate constant of 0.1954 min^–1, which is ∼41.6 and ∼16.8 times higher than those of the g-C₃N₄ (∼0.0047 min^–1) and Ag/AgCl (∼0.0116 min^–1), respectively. The degradation of methylene blue, methyl orange, and colorless phenol further confirmed the broad spectrum photocatalytic degradation abilities of Ag@AgCl-9/g-C₃N₄. These results suggested that an integration of the synergetic effect of suitable size plasmonic Ag@AgCl and strong coupling effect between the Ag@AgCl nanoparticles and the exfoliated porous g-C₃N₄ nanosheets was superior for visible-light-responsive and fast separation of photogenerated electron–hole pairs, thus significantly improving the photocatalytic efficiency. This work may provide a novel concept for the rational design of stable and high performance g-C₃N₄-based plasmonic photocatalysts for unique photochemical reaction