Preparation of iron selenide decorated 1T/2H molybdenum disulfide catalysts for peroxymonosulfate activation: Effect of phase transition

The sulfate radical-based advanced oxidation process is recognized as an effective approach for acetaminophen (ACT) degradation. Modification of MoS2 through phase engineering can contribute to enhancing peroxymonosulfate (PMS) activation performance. In this work, we decorated MoS2 with FeSe2, aiming to alter the 1T/2H phase ratio of MoS2. Experiments and calculations suggested that the incorporation of FeSe2 increases the activation pathway through the Fe(III)/Fe(II) cycle and prompts a phase transition from 2H to 1T, providing active sites and boosting charge transfer between FeSe2 and MoS2. The optimum catalyst (FeSe2@MoS2-10) showed high efficiency in PMS activation, achieving complete removal of ACT within 20 min. The pseudo-first-order rate constant (k(app)) on this catalyst is 17.7 times higher than that of the MoS2/PMS system. This study provides a new direction for promoting phase transition and improving the catalytic reactivity of MoS2-based catalysts, expanding their potential applications in pharmaceutical wastewater treatment.