Preparation of Si–α-Fe2O3/CdS composites with enhanced visible-light photocatalytic activity for p-nitrophenol degradation

Highlights: • The Si–α-Fe₂O₃/CdS heterojunction composites were fabricated. • The Si–α-Fe₂O₃/CdS showed a high capability to absorb visible light. • The Si–α-Fe₂O₃/CdS inhibited the recombination of the photogenerated electron–hole pairs. • The SFC-1:1 composite exhibited excellent visible-light photocatalytic activity. -- Abstract: Si–hematite (α-Fe₂O₃) nanosheets with highly exposed (110) facets were obtained first, and Si–α-Fe₂O₃/CdS composites were developed using a well-designed hydrothermal method. The prepared Si–α-Fe₂O₃/CdS composites showed enhanced visible-light photocatalytic activity compared with Si–α-Fe₂O₃ and CdS. The construction of the Si–α-Fe₂O₃/CdS heterojunction can inhibit the recombination of the photogenerated electron–hole pairs on the catalyst surface effectively. The synergistic effects of the photo-Fenton and the heterojunction promoted the production of the active species in the Si–α-Fe₂O₃/CdS system and enhanced the photocatalytic degradation activity under visible-light irradiation. The SFC-1:1 composite exhibited the highest photocatalytic activity toward p-nitrophenol degradation. The photocatalytic degradation mechanism was also investigated.