A nanoreactor with Z-scheme FeS₂/MoS₂ heterojunctions encapsulated inside the carbon capsule: Insight on preparation method and enhanced performance in photo-Fenton reaction

Catalytic reaction confined in the nanoreactor could be accelerated by taking advantage of confinement effect. Photo-Fenton reaction has already been verified as an effective technique for pollutant degradation. Therefore, it was rational to infer that the degradation performance of photo-Fenton reaction inside the nanoreactor could be further improved. Nevertheless, how to construct a suitable nanoreactor to realize the aim was still a challenge. Herein, FeS₂/MoS₂@C nanoreactor with FeS₂/MoS₂ heterojunctions encapsulated inside the carbon capsule was prepared using Fe-MIL-101 as hard template via ions exchange, chelation competition induced polymerization, and calcination in sequence. In photo-Fenton reaction, photo-induced e⁻ followed a Z-scheme transfer path, leading to the well-preserved redox capacity of separated e⁻ and h⁺. A large amount of reactive species were generated inside the capsule, and their contributions followed the order: ^•OH > h⁺>¹O₂>^•O₂ ^–. The complex catalytic mechanism was disclosed via tracing the source of reactive species. Furthermore, to better illustrate the confinement effect, the broken-FeS₂/MoS₂@C was prepared as a reference. The accelerated degradation rate, better visible-light harvest, enhanced photothermal effect, and higher yield of self-produced O₂ inside the integrated capsule were disclosed. This work illustrates the advantage of nanoreactor, and provides a new vision to improve the degradation performance in photo-Fenton reaction.