Enhanced electron transfer in FeS2-FeMoO4 heterojunction for nearly 100% singlet oxygen generation in efficient water remediation

Singlet oxygen ( 1 O 2 ) plays a crucial role in environmental catalysis owing to its long lifetime, strong electrophilicity, and high selectivity, whereas selective generation of 1 O 2 with conventional catalysts remains challenges. Herein, we for the first time construct a FeS 2 -FeMoO 4 heterostructure supported on graphene oxide (FeMoS-GO), and subsequently evaluate its efficacy in peroxymonosulfate (PMS) activation for degrading organic pollutants. Compared with non-heterostructures, our catalyst alters the electron density and coordination environment of Fe and Mo, enhancing electron transfer and facilitating the cyclic conversion of Fe 2+ /Fe 3+ during PMS adsorption and activation. Experiments indicate that FeMoS-GO generates nearly 100 % 1 O 2 , with concentrations two to three orders of magnitude higher than those of •OH and SO 4 •- . Density functional theory (DFT) calculations and electrochemical tests also support the high efficiency of electron transfer and PMS adsorption by heterostructure. The degradation for phenol of FeMoS-GO is 100 times faster than that of the non-heterogeneous structure, and its degradation rate for various organic pollutants exceeds 90 %, while also demonstrating satisfactory performance in interference and stability tests. Our findings offer new insights and approaches for the efficient and controlled generation of 1 O 2 in water treatment and environmental remediation.