1T/2H-MoS₂-Decorated Carbon Felts as Excellent Co-Catalysts in Advanced Oxidation Processes for the Degradation of Organic Pollutants

The Fenton reaction is restricted by the sluggish Fe(II)/Fe(III) cycle and the low activation efficiency of oxidants. Herein, 1T/2H MoS₂ nanoflowers with abundant defects and a multiphase structure, loaded on carbon felts (denoted as THMC), have been prepared to boost catalytic activity in Fenton-like oxidation. The defects and ultrathin nanosheets promote the adsorption of iron ions and pollutants, while the unsaturated S atoms and exposed Mo(IV) sites facilitate the conversion of Fe(III) to Fe(II). Additionally, the 1T phase accelerates electron transfer in Fe(II)/Fe(III) cycling, thereby synergistically enhancing catalytic activity in Fenton-like oxidation and improving the efficiency of pollutant elimination. Moreover, the loading of MoS₂ nanoflowers on carbon felts not only overcomes the limitations of powder in separation and recycling but also offers robust stability for long-term applications. Thanks to these structural characteristics, the degradation efficiencies of rhodamine B and bisphenol A in the THMC cocatalyzed system reach 99.3% and 98.1%, respectively, and the corresponding rate constants (<i>k</i>_obs) are 10.3 and 10.1 times higher than those of the traditional Fe²⁺-catalyzed system. Impressively, THMC still maintains excellent cocatalytic performance after 5 cycles and exhibits high degradation efficiencies across wide pH ranges. The cocatalytic system can efficiently eliminate a variety of organic pollutants and adapt to natural water samples. Furthermore, the performance of several MoS₂ nanoflowers with varied phase structures and phase ratios has been investigated to probe the effect of phase structure. Interestingly, the <i>k</i>_obs value of MoS₂ with 52.4% 1T phase was 5.9 and 3.4 times higher than that of 5.6%-1T MoS₂ in the degradation of RhB and BPA, respectively. Moreover, the cocatalytic performance of MoS₂ could be further improved with an increase in the 1T phase to 66.6%. These observations reveal the significant role of phase effects on the cocatalytic activity of MoS₂ in AOPs.