Z-Scheme In2S3/NU-1000 Heterojunction for Boosting Photo-Oxidation of Sulfide into Sulfoxide under Ambient Conditions

Photocatalytic oxidation of sulfide into sulfoxide has attracted extensive attention as an environmentally friendly strategy for chemical transformations or toxic chemicals degradation. Herein, we construct a series of In2S3/NU-1000 heterojunction photocatalysts, which can efficiently catalyze the oxidation of sulfides to form sulfoxides as the sole product under LED lamp (full-spectrum) illumination in air at room temperature. Especially, the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), can also be photocatalytically oxidized with In2S3/NU-1000 to afford nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) selectively and effectively. In contrast, individual NU-1000 and In2S3 show very low catalytic activity on this reaction. The significantly improved photocatalytic activity is ascribed to the constructing of an efficient Z-scheme photocatalysts In2S3/NU-1000, which exhibits the enhancement of light harvesting, the promotion of photogenerated electron-hole separation, and the retention of high porosity of the parent MOF. Moreover, mechanism studies in photocatalytic oxidation reveal that the superoxide radical (O-.(2)-) and singlet oxygen (O-1(2)) are the main oxidative species in the oxidation system. This work exploits the opportunities for the construction of porous Z-scheme photocatalysts based on the photoactive MOFs materials and inorganic semiconductors for promoting catalytic organic transformations. More importantly, it provides a route to the rational design of efficient photocatalysts for the detoxification of mustard gas.

Automated summary

In this study, a series of In2S3/NU-1000 heterojunction photocatalysts were constructed to efficiently catalyze the oxidation of sulfides into sulfoxides, with the ability to detoxify sulfur mustard simulant CEES. The enhanced photocatalytic activity was attributed to the Z-scheme photocatalytic system, which showed improved light harvesting, electron-hole separation, and porosity. Mechanism studies revealed superoxide radical and singlet oxygen as the main oxidative species in the system, offering insights for designing efficient photocatalysts for detoxification purposes.