2D/2D α-Fe2O3/single-layer MXene Schottky photocatalysis-PMS activation bidirectionally enhanced coupling system for environmental remediation

Photocatalytic process coupled with persulfate activation can produce a synergistic effect to release active groups, which is promising in the field of environmental remediation, but remains challenging. Herein, 2D/2D α-Fe2O3/single-layer MXene Ti3C2/Peroxymonosulfate (PMS) Schottky-scheme photocatalytic-PMS activation coupled system with bidirectional strengthening properties (significant charge separation and high PMS activation) is designed. It is found that α-Fe2O3/single-layer MXene Ti3C2 has excellent light absorption properties and utilization, and a Schottky junction is formed between the component interfaces, which promotes electron transfer and inhibits the recombination of photogenerated charges. The coupled PMS further promotes the charge separation of the material and achieves its own efficient activation. Impressively, α-Fe2O3/single-layer MXene Ti3C2/PMS exhibits ultra-high pollutant degradation activity with an apparent rate constant of 0.04613 min−1, which is 17.3 and 5.6 times higher than that of α-Fe2O3 and α-Fe2O3/PMS, respectively. It is further proved that 1O2 originating from the preferential reaction between photogenerated holes and PMS is the active group with the highest contribution. This work leads a suitable direction for designing coupled systems for environmental remediation using sustainable energy sources.