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

Abstract

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 µmol 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.