In-process Synthesis of a Ag/AgCl/g-C₃N₄ Ternary Heterojunction Photocatalysts for Plasmon Resonance Enhanced Polishing

Surface plasmon resonance has been generally employed to enhance the photoresponse in typical fields such as energy conversion and chemical sensing. In this study, we propose a plasmon resonance enhanced polishing (PREP) method based on in-process synthesized Ag/AgCl/g-C3N4 ternary heterojunctions, which overcomes three critical bottlenecks in conventional photochemical mechanical polishing including complex ex-process synthesis protocols, short-wavelength-limited photoresponse, and rapid charge carrier recombination. By synergistically integrating localized surface plasmon resonance (LSPR) from Ag nanoparticles with a Z-scheme charge transfer mechanism in the AgCl/g-C3N4 heterojunction, we achieve an expanded light absorption range up to 625 nm and significantly improve the separation efficiency of photogenerated carriers. Experimental results demonstrate that the in-process synthesized heterojunction photocatalysts facilitate a 3.02-fold increase in material removal rate under broad-spectrum solar illumination while maintaining close-to-atomic-level surface roughness (0.37 nm). This work not only provides fundamental insights into the dynamic construction of heterojunction architectures but also opens up new application scenarios of the heterojunction-based plasmon resonance phenomenon.