Modulating Electronic Structures of Cellulose‐Derived Carbon and Nitrogen Composite to Enhance Photocatalytic Degradation of Emerging Contaminants

Abstract Modeling photocatalytic techniques for developing innovative photocatalysts comes out as an efficient method to eradicate the emerging antibiotic contamination and remedy the polluted environment. Although massive efforts have been devoted to this, the related interfacial processes along with catalytic mechanism at the atomic level could be decisive yet remain unclear. In the work, a cellulose‐derived carbon composite has been prepared by coupling with graphitic carbon nitride. It achieves the photocatalytic degradation rate towards antibiotics (levofloxacin hydrochloride and ciprofloxacin hydrochloride) in water. The complementing density functional theory calculations suggest chemical couplings at catalyst‐adsorbate interface. This promotes electron‐hole interfacial transfer and spatial separation and boosts photocatalytic reactions. Degradation follows direct hole (h + ) and indirect •O 2 − oxidation mechanisms. Doping with nickel and zinc further modulates the electronic structures of the resulted catalyst. The raised oxidative ability of the nickel‐doped catalyst can oxidize H 2 O to give •OH, which opens an additional path that •OH degrades antibiotics.