MOF-derived yolk–shell CdS microcubes with enhanced visible-light photocatalytic activity and stability for hydrogen evolution

Yolk-shell structures with a unique three-dimensional (3D) open architecture offer great advantages for constructing advanced photocatalysts. However, metal sulfides with yolk-shell nanostructures were rarely reported. In this work, unique yolk-shell CdS microcubes are synthesized from Cd-Fe Prussian blue analogues (Cd-Fe-PBA) through a facile microwave-assisted hydrothermal process. Their formation mechanism is also proposed based on the anion exchange and Kirkendall effect process. Benefitting from structural merits, including a 3D open structure, small size of primary nanoparticles, high specific surface area, and good structural robustness, the obtained yolk-shell CdS microcubes manifest excellent performances for photocatalytic hydrogen evolution from H2O under visible-light irradiation. The photocatalytic H2 evolution rate is 3051.4 mu mol h-1 g-1 (with an apparent quantum efficiency of 4.9% at 420 nm), which is similar to 2.43 times higher than that of conventional CdS nanoparticles. Furthermore, the yolk-shell CdS microcubes exhibit remarkable photocatalytic stability. This work demonstrates that MOF-derived yolk-shell structured materials hold great promise for application in the field of energy conversion.