Photocatalytic Degradation and Antibacterial Properties of Fe3+-Doped Alkalized Carbon Nitride

Abstract

Discovering novel materials and improving the properties of existing materials are the main goals in the field of photocatalysis to increase the potential application of the materials. In this paper, a modified graphitic carbon nitride (g-C3N4) photocatalyst named Fe3+-doped alkalized carbon nitride, which couples the photocatalytic reaction with the Fenton reaction, is introduced to demonstrate its Rhodamine B (RhB) degradation and antibacterial properties. Under visible-light irradiation, the degradation rate of RhB was 99.9% after 200 min, while the antibacterial rates of Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) after 300 min were 99.9986%, 99.9974%, and 99.9876%, respectively. Moreover, the repetitive experiments of RhB degradation demonstrate that the proposed photocatalysts have excellent stability and reusability. The active free radical trapping experiments reveal that the superoxide radical (·O2−) is the dominant reactive oxygen species. In addition, the Fenton reaction is introduced into the photocatalytic system due to the doping of Fe3+, and the hydroxyl radical (·OH) produced from the Fenton reaction further enhances the photocatalytic performance. The remarkable improvement in photocatalytic performance of the proposed photocatalyst can be attributed to its broader UV–visible absorption characteristic and the occurrence of the Fenton reaction.

Microwave Synthesis of Visible-Light-Activated g-C3N4/TiO2 Photocatalysts

“…In this scheme, the photogenerated electrons in TiO 2 recombine with the holes in g-C 3 N 4 through the built-in electrostatic field, resulting in a more efficient separation of photogenerated charge carriers. Due to the more positive VB potential in TiO 2 (+2.6 V vs. NHE) than that in OH − /·OH (+1.99 V vs. NHE) and H 2 O/·OH (+2.37 V vs. NHE) [ 137 ], the holes can form hydroxyl radicals by reacting with adsorbed water molecules or surface hydroxyls at the surface of TiO 2 . At the same time, the electrons on the CB of g-C 3 N 4 could be captured by O 2 to form ·O 2 − radical species due to the more cathodic CB potential (−1 V vs. NHE) compared to the redox potential of O 2 /·O 2 − (−0.33 V vs. NHE) radicals [ 137 , 138 ].…”

Oxidative Injury in Ischemic Stroke: A Focus on NADPH Oxidase 4

“…O 2 − , having less transmembrane capacity, achieves better transmembrane ability via the conversion of O 2 − to H 2 O 2 . H 2 O 2 produces · OH through reacting with Fe 2+ to undergo the Fenton reaction [ 59 , 60 ].…”

Anion–Cation Co-Doped g-C3N4 Porous Nanotubes with Efficient Photocatalytic H2 Evolution Performance

“…However, the photocatalytic activity of pristine bulk g-C 3 N 4 is greatly restricted by its intrinsically low specific surface area and inadequate visible-light response range, and the rapid recombination of photogeneration electron–hole pairs originates from its organic π conjugated structure [ 4 , 5 , 6 , 7 ]. Therefore, a variety of g-C 3 N 4 -based photocatalysts with superior photocatalytic activity have been synthesized through multiple strategies, such as element doping [ 8 , 9 ], heterojunction construction [ 10 , 11 , 12 , 13 ] and morphology regulation [ 14 , 15 , 16 ].…”