Enhancing Organic Pollutant Degradation Efficiency through a Photocatalysis-Electro-Fenton System via MoS Crystal Morphology Regulation.

A photocatalysis-electro-Fenton (PEF) system was constructed via molybdenum disulfide (MoS) to remove tetracycline (TC) without an external oxidant supply and solution pH adjustment. In the system, original graphite felt (GF) was used as a cathode, from which HO was generated continuously under power. MoS was motivated by visible light to facilitate the cycle of Fe/Fe, enhancing the Fenton process to produce OH. The experimental results showed that the system can increase the degradation rate of pollutants by more than 5 times. Moreover, the quenching and electron paramagnetic resonance (EPR) tests demonstrated that OH was the dominant active species. X-ray photoelectron spectroscopy (XPS) characterization, Mo concentration, and cycle experiments proved the excellent catalytic activity and chemical stability of MoS. It is worth mentioning that the photocatalytic performances of different morphologies of MoS (flower, flake, and radar) were compared. As a result, flower-like MoS exhibited a much superior photoresponse than flake and radar, which could accelerate the Fe/Fe cycle further effectively. These findings highlight the morphology-performance relationship of MoS under a PEF system and the mechanisms of contaminant degradation, which is of great significance for developing photoelectric Fenton technology.