摘要： Herein, the photocatalytic roles of silver (Ag) and gold (Au) nanoparticles (NPs) on graphitic carbon nitride (CN) nanosheets is thoroughly investigated under UV (250-380 nm), UV-Vis (256-600 nm) and green laser (532 nm). Under UV light, Ag and Au NPs capture photogenerated electrons from CN and function as co-catalyst. The dual roles of Ag and Au, as co-catalyst as well as a plasmonic photocatalyst, lead to reduced RhB degradation under UV-Vis light. Bandgap excitation occurs in unison with surface plasmon resonance (SPR) under UV-Vis light. The synchronicity leads to forward and back electron transfer at the metal-semiconductor junction, thus increasing interfacial carrier recombination. The plasmonic systems show the best result under visible light (532 nm). Plasmonic hot electron injection from metal to CN triggers the SPR driven photocatalysis. The photoconductivity current-voltage (I-V) measurement indicates enhanced free-carrier generation under white light (400-730 nm) as well as under selective excitations at 405 nm, 470 nm, and 530 nm, respectively. These freely available carriers actively participate in photocatalysis.