Peroxymonosulfate activation by graphene oxide-supported 3D-MoS2/FeCo2O4 sponge for highly efficient organic pollutants degradation

To address conventional powder catalysts' recovery and aggregation issues that greatly restrain their practical application, a recoverable graphene oxide (GO)-supported 3D-MoS2/FeCo2O4 sponge (SFCMG) was developed through a simple impregnation pyrolysis method. SFCMG can efficiently activate peroxymonosulfate (PMS) to produce reactive species for rapid degradation of rhodamine B (RhB), with 95.0% and 100% of RhB being removed within 2 min and 10 min, respectively. The presence of GO enhances the electron transfer performance of the sponge, and the three-dimensional melamine sponge serves as a substrate to provide a highly dispersed carrier for FeCo2O4 and MoS2/GO hybrid sheets. SFCMG exhibits a synergistic catalytic effect of Fe and Co, and facilitates the redox cycles of Fe(III)/Fe(II) and Co(III)/Co(II) by MoS2 co-catalysis, which enhances its catalytic activity. Electron paramagnetic resonance results demonstrate that SO4•−, ·O2− and 1O2 are all involved in SFCMG/PMS system, and 1O2 played a prominent role in RhB degradation. The system has good resistance to anions (Cl−, SO42−, and H2PO4−) and humic acid and excellent performance for many typical contaminants degradation. Additionally, it works efficiently over a wide pH range (3–9) and possesses high stability and reusability with the metal leaching far below the safety standards. The present study extends the practical application of metal co-catalysis and offers a promising Fenton-like catalyst for the treatment of organic wastewater. [Display omitted] •A novel 3D-FeCo2O4@MoS2/GO sponge was prepared via impregnation pyrolysis method.•MoS2/FeCo2O4 heterojunction contributed to the high stability.•Co-catalysis of Mo, Fe and Co can effectively activate PMS.•O21 and SO4.− were the main reactive species generated in SFCMG/PMS.•Synergistic catalytic mechanism of FeCo2O4@MoS2/GO sponge was elucidated.