Constructing an S-scheme Fe2O3/MnS heterojunction for efficient photocatalytic H2 evolution in visible light

A series of S-scheme Fe2O3/MnS heterojunction composites have been successfully fabricated through the hydrothermal method by loading Fe2O3 onto the surface of MnS. The XRD demonstrates that the crystalline structure of MnS remains unaltered after loading with Fe2O3. SEM and TEM tests revealed that Fe2O3 is uniformly loaded on the MnS surface and tightly bound to it, forming a high-quality S-scheme heterojunction. Moreover, XPS analysis and work function theory data imply that an internal electric field (IEF) is generated at the interface between Fe2O3 and MnS. Moreover, the IEF not only effectively boosts the separation and transfer of carriers but also greatly preserves the powerful reducing property of MnS conduction band electrons and the strong oxidation property of Fe2O3 valence band holes. The outcomes of hydrogen production by water splitting tests show that the Fe2O3/MnS composite has better hydrogen production performance than pure MnS and Fe2O3. When the loading amount of Fe2O3 reaches 6 wt%, the photolytic hydrogen production rate of the Fe2O3/ MnS attains its optimal level, approximately 1075 mu mol center dot g- 1 center dot h- 1, which is approximately 4.7 times that of MnS and 3.2 times that of Fe2O3, respectively. After four cycles, the hydrogen production capacity of Fe2O3/MnS do not show a significant decrease, indicating the favorable reusability of the Fe2O3/MnS composite catalyst.