Interface engineering: Graphdiyne (g-CnH2n-2) encapsulation of sulfur-rich Mn-Cd-Prussian blue analog for photocatalytic hydrogen evolution

The utilization of renewable energy represents a viable strategy towards achieving global carbon neutrality and mitigating carbon emissions. One of the research avenues pertaining to hydrogen energy involves the utilization of solar energy to facilitate the decomposition of water via semiconductors, thereby generating hydrogen. In this study, the sulfur-rich MnCd Prussian blue analogue (MnCd-PBA-S) octahedral structure was synthesised for the first time. The obtained GDY two-dimensional nanosheets coupled with MnCd-PBA-S produced surprising photocatalytic hydrogen production efficiency. The hydrogen production rate of the GDY/MnCd-PBA-S composite photocatalyst could reach 7.78 mmol g−1 h−1, which is 5.4 and 84.5 times higher than that of pure MnCd-PBA-S and GDY, respectively. Comprehensive characterization and DFT calculations show that GDY two-dimensional nanosheets can promote the outward movement of photogenerated holes and isolate the oxidation sites on the surface, which greatly promote the separation of electrons and holes in space. GDY is like a “protective film” of octahedral structure, and it reduces the photocorrosion of MnCd-PBA-S. The special spatial structure and synergistic effect of the S-scheme heterojunction constructed by the two can significantly reduce the recombination of electron-hole pairs. This work expands the application of organic photocatalysts and shows the great potential of GDY for photocatalytic water separation.