In-situ XPS monitoring bimetallic Prussian blue analogs and metal oxides heterojunction for photocatalytic hydrogen production

Here, the binary catalyst NiFe PBA@Cu2O with p-n heterojunction is successfully constructed by coupling metal Prussian blue analogs (NiFe-Prussian blue analog) with metal oxide (Cu2O). As a demonstration case, the NiFe PBA@Cu2O photocatalytic system with EY as the photosensitizer has excellent catalytic activity (4680.6 μmol·h−1·g−1) and stability, being 4.85 and 128.6 times that of NiFe PBA and Cu2O, respectively. The increased catalytic activity can be attributed to the synergistic action of NiFe PBA and Cu2O. On the one hand, the introduction of Cu2O with nanosphere structure can effectively prevent the aggregation of NiFe PBA cubes and improve the utilization rate of sunlight. NiFe PBA loaded on the Cu2O surface provides a rich active site for the catalytic reaction. On the other hand, the built-in electric field established between NiFe PBA and Cu2O significantly facilitates the transfer and separation of photo borne carriers. In situ XPS verifies the formation of the p-n heterojunction, and the p-n heterojunction formed at the NiFe PBA and Cu2O interfaces can provide a channel for effective charge transfer, helping to improve the photocatalytic hydrogen evolution capacity. This work provides a new direction for the rational design of p-n heterojunctions, and shows the potential application prospects in the field of renewable energy production.