Synergistic enhancement in dual-ligand MOF composites: O-doped carbon nitride mediated CNQDs anchoring for boosted photocatalytic performance

Metal-organic skeletons (MOFs) with low conductivity and insufficient response to visible light have limited their development in the field of photocatalysis. The adjustable pore structure, large surface area, and ease of surface modification of MOFs provide opportunities to further improve the photocatalytic performance. This study reports the synthesis of flower-like zinc-based MOFs with hierarchical structure using two ligands as organic linkers. The heterojunction constructed by doping graphitic carbon nitride (g-C 3 N 4 ) catalysts effectively tuned the energy band structure of the MOFs to adapt to specific photo responses. Especially, the introduction of the heteroatom O into g-C 3 N 4 (OCN) again adjusts its electronic structure and thus improves its visible light utilization. The further incorporation of carbon nitride quantum dots (CNQDs) improves the charge separation efficiency and facilitates the division of photogenerated electron-hole pairs. The catalyst exhibited excellent visible light trapping and electron transfer properties with 90.46 % tetracycline (TC) degradation within 60 min. The free radical burst experiments and results indicate that the key active substances in the catalytic process are ·O 2 - with h + . This study introduces a novel approach to developing MOF-derived materials with environmental functionality.