Unique S-scheme structures in electrostatic self-assembled ReS₂-TiO₂ for high-efficiency perfluorooctanoic acid...

Perfluorinated compounds (PFCs), recognized as persistent organic pollutants, resist degradation in the environment due to the high bond energy of the C-F. Increasing carrier density via adopting electrostatic self-assembly strategy has been shown to effectively cleave C-F bonds. In this work, a unique S-scheme structure was fabricated by combining oppositely charged semiconductors, TiO₂ and ReS₂, through electrostatic self-assembly. The resulting 2 % ReS₂-TiO₂ composite achieved a photodegradation efficiency of 98 % for perfluorooctanoic acid (PFOA), considerably higher than the 62 % efficiency observed for pure TiO₂. Additionally, the 2 % ReS₂-TiO₂ composite demonstrated broad applicability for the removal of other PFCs. The introduction of ReS₂, with a lower work function than TiO₂, could generate an internal electric field (IEF) to facilitate electron transfer from TiO₂ to ReS₂ under continuous irradiation and thereby enhance charge separation efficiency.