Bismuth sulfide bridged hierarchical Bi2S3/BiOCl@ZnIn2S4 for efficient photocatalytic Cr(VI) reduction.

• Bi 2 S 3 /BiOCl@ZnIn 2 S 4 composite with Bi 2 S 3 as transition layer was constructed. • Bi 2 S 3 /BiOCl@ZnIn 2 S 4 shows high activities on Cr(VI) photocatalytic reduction. • The efficiency is 3.3 and 24.1 times as high as that of ZnIn 2 S 4 and Bi 2 S 3 /BiOCl. • The intimate heterostructure causes the boosted photocatalytic activity. Delicate construction based on 2D epitaxial heterostructure can be an effective route to adequately excavate and utilize its superiorities. Here, a core-shell Bi 2 S 3 /BiOCl@ZnIn 2 S 4 hierarchical heterostructure is rationally designed and built by Bi 2 S 3 epitaxial growth on two-dimensional template-like BiOCl and ZnIn 2 S 4 nanosheets in-situ growth. The epitaxial growth of Bi 2 S 3 on BiOCl endows the tight contact between them. More importantly, Bi 2 S 3 as the interlayer could offer an extra intimate junction to ZnIn 2 S 4 due to the chemical interaction of S2− between Bi 2 S 3 and ZnIn 2 S 4. Such a Bi 2 S 3 /BiOCl@ZnIn 2 S 4 composite was explored for visible-light-driven reduction of Cr(VI), and much satisfactory performance was achieved, which is about 3.3 and 24.1-fold increase compared to that of ZnIn 2 S 4 and Bi 2 S 3 /BiOCl respectively. Efficient generation, separation and transfer of photo-generated charge carriers inherited from this ternary hierarchical composite made significant contributions to the highly elevated photocatalytic activity. This work may stimulate the construction of multiple hierarchical composites based on 2D epitaxial heterostructure material for efficient photocatalysis or other optoelectronics. [ABSTRACT FROM AUTHOR]