Ni-Co Prussian blue analogues with tunable defects as heat-core materials for achieving ultra-high photothermal-assisted photocatalytic H2 production

Construction of photocatalysts coupling excellent electron transfer and photoresponsivity to enhance photocatalytic performance remains a challenging mission. In this study, Ni-Co Prussian blue analogues@ZnIn2S4 (NCPBA-Ds@ZIS) S-scheme heterojunctions enriched with [Co(CN)6]3- deficiency engineering and synergistically modified with an outstanding localized surface plasmon resonance (LSPR) effect are rationally designed for achieving ultra-high photothermal-assisted photocatalytic hydrogen (H2) production. The defect introduction and LSPR effect of NCPBA-Ds@ZIS not only optimizes the electronic structure and promotes the migration of photo-generated carriers, but also significantly broadens the light absorption range, exhibits excellent photothermal effect increases the overall temperature of the photocatalytic system, reducing the potential barrier of the photocatalytic H2 production reaction, and promoting the reaction kinetics. Furthermore, the S-scheme heterojunction efficiently utilizes electron-hole pairs with higher redox capacity to achieve spatial separation of carriers. The photocatalytic H2 production activity of the optimal NCPBA-Ds@ZIS sample was 38.3 mmol h−1 g−1 at simulated solar irradiation (AM 1.5 G), and the corresponding apparent quantum efficiency (AQE) was 18.2 % at the wavelength of 420 nm. This work serves as a direction to understand the relationship between the defect structure of Prussian blue analogues and photothermal properties, providing an efficacious approach for the development of photothermal-assisted photocatalytic systems with ultra-high photocatalytic activity.