Bifunctionalized Fe7S8@MoS2–O core-shell with efficient photocatalytic activity based on internal electric field

The photocatalytic degradation of toxic water pollutants (dyes, antibiotics, microorganisms, etc.) have attracted much attention, but the lack of catalysts with strong visible light absorption and long carrier life have limited the sustainable development of clean water worldwide. In order to solve this problem, the one-pot hydrothermal method was employed to fabricate Fe 7 S 8 @MoS 2 –O conduct-semiconductor-type catalyst for the first time. Fe 7 S 8 @MoS 2 –O appears as a core-shell structure. Malachite green (MG) and Levofloxacin (LVX) could be efficiently decomposed by Fe 7 S 8 @MoS 2 –O (75.7% and 81.3%, respectively) within 80 min and be further increased to 97.5% and 92.7% with peroxymonosulfate (PMS). The high disinfection performance for Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) are also obtained within 30 min (2.11 × 10 7 cfu/mL of S. aureus and 2.96 × 10 5 cfu/mL of E. coli inactivation). As a remarkable co-catalyst, the oxygen incorporated MoS 2 (MoS 2 –O) was introduced into Fe 7 S 8 to construct conductor-semiconductor-type heterojunction, which not only greatly facilitates Fe 3+ /Fe 2+ cycle to yield a large number of active radicals but also builds a internal electric field (E-field) to accelerate charge carrier transport. The band structures of Fe 7 S 8 and MoS 2 is conducted to elucidate the electronic structures of the photocatalyst according to the density functional theory (DFT) calculation. This study provides a strategy to design the efficient photocatalyst for environmental remediation. • Fe 7 S 8 @MoS 2 –O has been fabricated by one-pot hydrothermal method. • This catalyst exhibits core-shell structure and facilitates charge separation. • An internal E-field is constructed between Fe 7 S 8 conductor and MoS 2 –O semiconductor. • Pollutants were efficiently removed (97.5% for MG and 92.7% for LVX). • High disinfection performance for S. aureus and E. coli are obtained.