PMS activation over MoS2/Co0.75Mo3S3.75 for RhB pollutant oxidation removal in fuel cell system

In advanced oxidation processes (AOPs), organic pollutants are oxidized, but getting the most energy out of pollutant in reducing cost of AOPs is still a challenge. In this study, MoS2/ Co0.75Mo3S3.75 composite nano-catalyst with high density catalytic active sites was synthesized by homogeneous and dispersed doping of single Co atoms in MoS2 by one-step hydrothermal method. The prepared catalyst was coated on stainless steel with silica sol for electrode application under visible light and activation of PMS (peroxymonosulfate) in Photocatalytic fuel cell (PFC) system. The synergy system at pH 6.5, visible light irradiation and 0.06 mM [PMS], was able to rapidly degrade RhB (50 mg·L−1) within 10 min and reach 98% degradation within 21 min (kinetic rate constant 0.261 min−1). The role of visible light contributes to RhB degradation more than oxidation by just PMS in PFC (Photocatalytic Fuel Cell). The dispersed Co sites have a significant effect of activating PMS, improving catalytic activity and enhancing reaction under closed circuit. The system has good stability, is also applicable to significant removal of tetracycline(TC, 76.35%) and bisphenol A (BPA, 53.76%). In MoS2/ Co0.75Mo3S3.75-vis/PMS/PFC, species such as •OH, SO4•−, O2•−, h+ and 1O2 jointly promote the degradation of RhB. This work provides a perspective for further study of two-dimensional metallic sulfide doped with transition metal ions and application of such vis/PMS/PFC system in removing other toxic pollutants.