ZIF-67 dodecahedron coupled with CoAl-layered double hydroxide as S-scheme heterojunction for efficient visible-light-driven hydrogen evolution

Photocatalytic hydrogen generation is a potential strategy to solve the problem of energy shortage and environmental pollution. In this study, we adopted a novel in-situ growth scheme to construct the ZIF-67@CoAl LDH S-scheme heterojunction composite photocatalyst based on morphology modulation and energy band structure design. The outstanding catalytic performance of the composite photocatalyst can be ascribed to the following aspects: 1) the large specific surface area of ZIF-67 dodecahedron could provide abundant active sites; 2) the serious aggregation of CoAl LDH nanosheets were efficiently broken; 3) the light absorption of the composite catalyst were improved; 4) the recombination of photogenerated electrons and holes is effectively inhibited by the architecture of S-scheme, that abound electrons could involve in hydrogen evolution reactions. Thus, the hydrogen production of ZIF-67@CoAl LDH could reach 606.26 mu mol h-1 g-1, which equal to 8.4 and 26.1 times that of pristine ZIF-67 and pure CoAl LDH. This work will provide a new insight in the construction of heterojunction photocatalysts.

Automated summary

In this study, a novel ZIF-67@CoAl LDH S-scheme heterojunction composite photocatalyst was constructed based on morphology modulation and energy band structure design. The outstanding catalytic performance of the composite photocatalyst is attributed to abundant active sites, efficient fragmentation of nanosheets, improved light absorption, and effective inhibition of electron-hole recombination. The hydrogen production of ZIF-67@CoAl LDH reached 606.26 μmol/h·g, which is 8.4 and 26.1 times higher than pristine ZIF-67 and pure CoAl LDH, respectively. This work provides new insights for the construction of heterojunction photocatalysts.