Construction of a CuO/K-PCN p-n heterojunction with regulated band structure for enhanced visible Light-Driven Photocatalytic-Fenton disinfection activity

The photocatalytic heterogeneous Fenton process has garnered significant attention from researchers. This study successfully synthesized composited CuO nanoparticles with K-doping graphitic carbon nitride (K-PCN). The combination of CuO and K-PCN formed a p-n heterojunction, generating an internal electric field at the contact interface. By regulating the energy band position of PCN through K-doping, the thermodynamic transfer trend of photogenerated electrons became consistent with the electric field trend, leading to enhanced migration of electrons. Consequently, the photocatalytic and Fenton reactions exhibited better synergy, resulting in higher production of hydroxyl radicals and improved bactericidal performance. Under visible light irradiation, the CuO/K-PCN system demonstrated great bactericidal performance, achieving increased inactivation efficiency, from 2.8-log to 7-log in 25 min. The catalysts were characterized using SEM, TEM, XPS, FT-IR, XRD, and EPR techniques. Also, CuO/K-PCN displayed a broader wavelength range of light response. And, an efficient small-scale flow reactor further displayed the practical application potential of the CuO/K-PCN-based system. This research offers a straightforward and efficient method for thorough water disinfection using solar energy.