Construction of ternary hierarchical heterostructures with favorable interfacial compatibility for ultrahigh photocatalytic H2O2 production

Sluggish charge transfer dynamics are still the key issue limiting the development of photocatalysis. In this study, CdS/ZnIn 2 S 4 /MIL-53-NH 2 ternary hierarchical heterostructures were constructed via a building block approach, where ZnIn 2 S 4 lamellae first grow on MIL-53-NH 2 followed by CdS nanoparticle deposition. The favorable interfacial compatibility and ternary heterostructures contribute to rapid and multistep spatial charge transfer, which suppresses charge recombination. Therefore, ultrahigh H 2 O 2 production of 1792 μmol·L −1 was obtained over CdS/Znln 2 S 4 /MIL-53-NH 2 composites with visible light, pure water and ambient air, which is not only higher than that of each monomer and binary heterostructure but also better than those of most reported references. Notably, the apparent quantum yield reached 4.5 % at 400 nm, and the solar-to-H 2 O 2 conversion efficiency was 0.081 % in pure water and ambient air. Additionally, H 2 O 2 generation over CdS/Znln 2 S 4 /MIL-53-NH 2 composites involves two-electron O 2 reduction with ·O 2 - as an intermediate. This work may encourage heterostructure design for efficient photocatalytic H 2 O 2 production.