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.