Mesoporous I-doped-g-C3N4 with C Vacancies as Superior Visible-light-driven Photocatalyst for Removal of Tetracycline Antibiotic

Abstract

The discovery of g-C3N4 (GCN) has attracted great attention for antibiotic pollutants from wastewater. Nonetheless, photocatalytic performance of GCN suffers from rapid recombination, limited surface area, and restricted under visible light irradiation. In this work, different concentrations of mesoporous I-doped GCN were synthesized. Mesoporous I-doped GCN with 0.50g of I dopant (GCN-I0.50) manage to photodegrade 99.8% of TC within 150min under visible light (λ > 420nm). The tetracycline (TC) antibiotic photodegradation rate increased by 2.64 times than that of parent GCN. It is proven that I-dopant and generation of C vacancy provides extra electrons to reconstruct the GCN network. This led to a stronger driving force in photo-oxidation photodegradation. The C vacancy also acts as a trap to prevent fast charge recombination. Subsequently, the substantial surface area and mesoporous nature of GCN-I0.50 (63.76 m2/g) facilitate the breakdown of a greater quantity of TC pollutants. In addition, the structural distortion of GCN-I0.50 has promoted n-π* transition, extended photoactivity to visible light region due to smaller band gap (2.45eV). The GCN-I0.50 photocatalyst significantly improved the TC photodegradation rate with good stability.