Construction of PdS@MIL-125-NH2@ZnS type-II heterostructure with efficient charge separation for boosted photocatalytic hydrogen evolution

A new photocatalyst, [email protected]2-MIL-125(Ti)@ZnS (PdS/M125/ZnS) heterojunction is fabricated for photocatalytic H2 generation for the first time, where PdS nanoparticles are anchored in the pore of M125 by utilizing its confinement effect, and the ZnS is closely wrapped on the surfaces of the MOFs. The optimal photocatalyst exhibits a significantly enhanced H2 generation rate of 1164.2 μmol/g/h, while the pure M125 only displays a H2 generation rate of 16.7 μmol/g/h. The resultant improvement can be ascribed to the following comprehensive advantages. The hierarchical structure built by PdS, M125, and ZnS can form lots of intimate interfaces, offer abundant sites for reaction, and smooth channels for charge carriers due to the porous characteristics of MOFs. Moreover, M125 and ZnS with inner defect levels form an analogous type-II heterojunction assisted by PdS co-catalyst, which greatly promotes charge separation. This work may supply a new avenue to design MOFs photocatalysts for energy conversion.