MOF-derived bimetallic Fe-Ni-P nanotubes with tunable compositions for dye-sensitized photocatalytic H2 and O2 production

Abstract Dye-sensitized systems show promising in photocatalysis because they can separate the tasks of light absorption, charge generation and surface catalysis to two coupled components. In this system, it is crucial to develop suitable catalysts capable of receiving dye-injected charges and having high activity to a given reaction. Aiming to photocatalytic H2 and O2 production, we present a metal-organic framework derived route to prepare bimetallic Fe-Ni-P nanotubes using Fe-Ni-MIL-88 nanorods as templates. When integrated with different dyes, these Fe-Ni-P nanotubes can serve as efficient catalysts for photocatalytic H2 and O2 production, respectively. Additionally, catalytic activities of such dye-sensitized systems can be conveniently regulated by tailoring the metal compositions in Fe-Ni-P nanotubes. The photocatalytic H2 production of Fe1-Ni2-P can reach 5420 μmol gcat−1 h−1 under eosin-Y sensitization, which is 24 times and 6.7 times higher than Fe2P and Ni2P, respectively. The photocatalytic O2 production of Fe1-Ni2-P can reach 900.3 μmol gcat−1 h−1 under [Ru(bpy)3]Cl2 sensitization, about 4.6 times and 2.9 times higher than Fe2P and Ni2P. The roles of different components in the system have been explored and corresponding working mechanism is proposed. This work demonstrates a new type of dye-sensitized systems consisting of bimetallic phosphides and provides a facile route to regulate their photocatalytic performance.