Photo-assisted self-assembly synthesis of all 2D-layered heterojunction photocatalysts with long-range spatial separation of charge-carriers toward photocatalytic redox reactions

Abstract

Constructing heterojunction photocatalysts has been proven as an ingenious tactic to adjust the lifetimes of the higher redox-active charge-carriers toward highly-efficient photocatalytic applications. Numerous recent efforts focused on the short-range spatial separation of charge-carriers in the heterojunction photocatalysts. However, engineering a long-range transfer channel in the well-designed heterojunction photocatalyst to further spatially separate the charge-carriers is still a huge challenge. In this contribution, we developed a facile photo-assisted self-assembly strategy to synthesize the all 2D-layered heterojunction photocatalysts of SnS2/RGO/g-C3N4 nanosheets (NSs). During the synthesis process, the precursor of 2D graphene-oxide (GO) NSs was converted into the reduced GO (RGO) NSs by the photoactive semiconductors of 2D SnS2 and g-C3N4 NSs. Meanwhile, the above two 2D semiconductors were simultaneously anchored onto the surface of the RGO NSs. Upon visible-light irradiation of the synthesized SnS2/RGO/g-C3N4 NSs, the 2D RGO component could provide a broad electron-transfer surface for the long-range spatial-separation of charge-carriers in the semiconductor components of the NSs. Thus, this all 2D-layered heterojunction photocatalyst exhibited ∼ 9.2 and ∼ 4.6-fold enhancement on the photocatalytic oxidation degradation of the organic dye, and ∼ 68 and ∼ 3.4-fold enhancement on photocatalytic protons reduction as compared to the pure SnS2 and g-C3N4 NSs, respectively.