The construction of high efficient visible-light-driven 3D porous g-C3N4/Fe3O4 photocatalyst: A new photo-induced bacterial inactivation material enhanced by cascade photo-Fenton reaction

Photocatalytic disinfection is considered a promising method for eliminating the hazards of pathogenic bacteria. Graphitic carbon nitride (g-C 3 N 4 ) is an ideal photocatalytic bacterial inactivation material for its advantage of tunable band structure, good stability and easy preparation. This work has constructed a novel defective 3D porous g-C 3 N 4 by cyanamide carbonation using dendritic mesoporous silica template. The direct loading of Fe 3 O 4 nanoparticles provided an excellent pg–C 3 N 4 –Fe 3 O 4 photocatalyst suitable for water disinfection . Compared to pristine g-C 3 N 4 , the prepared 3D porous defective g–C 3 N 4 –Fe 3 O 4 exhibited the enhanced visible light absorbance as indicated by the band gap decreasing of 0.66 eV, and about 3 and 10 fold increase of photo-induced current response and O 2 adsorption respectively. The pg–C 3 N 4 –Fe 3 O 4 showed excellent visible-light-driven photocatalytic bactericidal activity. It could kill 1 × 10 7  cfu mL −1 Escherichia coli completely within 1 h under visible-light illumination (100 mW cm −2 ) with good reusability, its logarithmic bacterial inactivation efficiency was about 2.5 fold higher than pg-C 3 N 4 . The enhanced bactericidal performance is mainly ascribed to the Fe 3 O 4 involved cascade photo-Fenton reaction.