4. Conclusion
In this work, we developed a novel in-situ growth scheme to construct
the Cu-MOFs@ZIF-9(Co) core-shell precursor material. The
Cu-MOFs@ZIF-9(Co) core-shell precursor was treated by low-temperature
phosphorization to obtain a Cu3P@CoP composite catalyst
with a self-supporting structure. The composite Cu-Co-2P-2 was obtained
by controlling the phosphation degree of Cu-MOFs@ZIF-9(Co) precursor and
adjust the ratio of Cu and Co, and Cu-Co-2P-2 composite had the highest
hydrogen production activity reaching 469.95μmol within 5 h. Experiments
to control the degree of phosphation of Cu-MOFs@ZIF-9(Co) precursor
material and adjust the ratio of Cu to Co show that the photocatalyst
recorded as Cu-Co-2P-2 has the highest hydrogen production activity,
reaching 469.95 μmol in 5h. The unique structure and composition of
Cu3P@CoP can promote charge migration, provide large
surface area and rich active sites to drive water photolysis.
Cu3P@CoP composite catalyst not only has a layered
structure, but also builds a p-n heterojunction at the interface of
Cu3P and CoP. The results of photoelectrochemical and
fluorescence tests showed that the proper conduction and valence band
positions of Cu3P and CoP formed a more effective path
way for the thermodynamic charge transfer. The results further emphasize
the importance of material design based on proper energy level
locations.
This
work will promote the design of transition metal phosphide semiconductor
devices and further development of heterojunction photocatalysts.