Two dimensional metal-organic frameworks-derived leaf-like CoS/CdS composite for enhancing photocatalytic water evolution.

The two dimensional (2D) lamellar structure materials with micron length of lateral can offer abundant reactive sites, high surface area and high flexibility for separating the photo-induced electron-hole pairs, and the obtained nanosheets possess tremendous potential to achieve efficient photocatalytic performance. Herein, we design and successfully synthesize 2D MOF-derived leaf-like structured CoS decorated with CdS photocatalyst by a facile method, which possesses a lateral size of 3-6 μm with the thickness of 130-160 nm. The maximum optical absorption wavelength of CoS/CdS extends remarkably from 570 nm to 720 nm in visible light region compared with pure CdS nanospheres, demonstrating that the CoS/CdS hybrid material has higher solar energy utilization efficiency. Benefited from the structural advantages and the improvement of the absorption region, the optimized CoS/CdS (0.2) exhibits superior hydrogen production performance, and the amount of H reaches 5892.6 μmol h g under continuous visible-light illumination. Notably, the result manifests over 6 times greater than the neat CdS nanoparticles. Above all, this work provides a remarkable stepping stone in rationally constructing 2D MOF-based composite materials for sustainable energy sources applied in the field of photocatalytic hydrogen evolution.