Modulation of morphology and phase of magnetically separable 1T-WS2/CuFe2O4 heterojunctions for acceleration of peroxymonosulfate decomposition for rapid degradation of phenol

Abstract

Transition metal sulfides are often used as cocatalysts to activate Peroxymonosulfate (PMS) in Fenton-like systems, but the problems include difficulties in recycling and the need to inject iron ions. In this paper, a self-synthesized magnetically recoverable heterogeneous 1 T-WS2/CuFe2O4 composites was prepared for the first time via a two-step hydrothermal method, and the content of the 1 T phase in WS2 was adjusted by controlling the hydrothermal temperature. Analytical techniques, such as XRD, Raman, SEM, TEM, BET, XPS, and VSM, showed that the composite catalyst was prepared with good particle shapes and high content of the 1 T phase. At the optimal dosage, this material activated PMS degraded to 93.6 % of 20 mg/L phenol in 50 min. The system exhibited high degradation efficiency, excellent interference resistance and good cycling stability under different conditions, and sulfur vacancies were generated during the process. ESR, quenching experiments, and other analyses confirm that SO4−, OH and 1O2 are the main active species in the system, with 1O2 making the greatest contribution. The degradation pathway of phenol was analyzed, and the formation of 12 intermediate products was qualitatively identified. Additionally, a simulation analysis of the toxicity of intermediate products was conducted. The degradation mechanism indicated that the three redox couples, Cu+/Cu2+, Fe2+/Fe3+ and W4+/W6+, provided synergistic activation of PMS. The self-synthesized 1 T-WS2/CuFe2O4 composite showed high catalytic performance, good stability, a high magnetic recovery rate and a low ion leaching rate and shows promise for treating concentrated organic wastewater.