Significantly improved photocatalysis-self-Fenton degradation performance over g-C3N4 via promoting Fe(III)/Fe(II) cycle

Photocatalysis-self-Fenton system, i.e., photocatalytic H2O2 generation and utilization in situ for ·OH radials production to remove organic pollutants with high-fluent degradation and mineralization performance possesses such advantages as cleanliness, efficiency and safety. However, its degradation activity always suffers from the Fe(III)/Fe(II) cycle. For this reason, graphitic carbon interface-modified g-C3N4 (CUCN) was fabricated to remarkably improve photocatalysis-self-Fenton degradation activity. The experiment results indicated that CUCN-2% photocatalyst, in which the loading percentage of graphitic carbon was 2%, demonstrated the optimum degradation performance among all the counterparts. The mineralization degree for RhB in 3 h over CUCN-2% reached 63.77%, nearly 3.35-fold higher than the pristine g-C3N4. The significantly improved mineralization efficiency was ascribed to the promoted Fe(III)/Fe(II) cycle by photogenerated electrons, which leading to the higher utilization efficiency of H2O2 through Fenton reaction, thereby producing more hydroxyl radicals. It is anticipated that our work could provide new insights for the design of photocatalysis-self-Fenton system with exceptional degradation performance for actual photocatalytic applications.Graphical abstract