Breaking through electronic bottlenecks: Fe3S4/MoB MBene Schottky junctions enable rapid charge transfer, driving efficient photocatalytic hydrogen production

Semiconductor-based photocatalytic hydrogen evolution represents a promising pathway for converting solar energy into clean chemical fuels. However, its widespread application remains hindered by the scarcity of highly efficient, precious-metal-free co-catalysts. This study synthesized MoB MBene via molten salt and acid etching, then prepared Fe3S4/MoB MBene composite photocatalysts using a solvothermal in situ growth method. Hydrogen production tests revealed that the optimized Fe3S4/MoB MBene composite achieved a peak hydrogen production rate of 31.2 mmol g−1 h−1, representing a 48-fold increase over pure Fe3S4. The outstanding performance of MoB as a co-catalyst primarily stems from its high conductivity and large specific surface area. When Fe3S4 contacts MoB, an internal electric field and Schottky barrier are formed due to the difference in their Fermi levels. This facilitates efficient electron transfer from Fe3S4 to MoB while suppressing the recombination of photogenerated carriers. The synergistic effect between the two components significantly enhances photocatalytic hydrogen production performance. Furthermore, MoB's two-dimensional layered structure enables uniform adhesion of Fe3S4 onto its surface, effectively suppressing Fe3S4 agglomeration and oxidation. By demonstrating the effectiveness of MBenes as a co-catalyst, this work provides a novel, low-cost, and highly efficient strategy for advancing high-performance solar-to-hydrogen conversion systems.