Cobalt-Doped MIL-88A Anchored on Cellulose Filter Paper: A Recyclable Flow-Through Catalyst for Peroxymonosulfate Activation in the Degradation of Organic Dyes

Abstract

To demonstrate an effective use of a heterogenous catalyst for the treatment of wastewater under a flowing state, we synthesized a metal-organic framework, specifically MIL-88A, in situ on filter paper. A cobalt doping modification yielded a composite catalyst, Co-doped MIL-88A on filter paper (Co-M88A-FP), that was then used to activate peroxymonosulfate (PMS). Characterizations of our Co-M88A-FP catalyst revealed that the morphology and structure of the MIL-88A did not change when synthesized on filter paper; however, the surface of the MIL-88A became rough and amorphous after Co doping. Using Rhodamine B as the test pollutant dye, the Co-M88A-FP and PMS catalytic system exhibited highly efficient degradation performance that appears to be adaptable to continuous flow conditions. The XPS, EPR and radical scavenging test results indicated that singlet oxygen was the reactive species that mainly contributed to the degradation of our test pollutant. Therefore, electron-rich substances with low steric hindrance would be degraded more quickly through the Co-M88A-FP/PMS system.