Localized proton enrichment by Fe-MoS2NF boosts Fenton-like reactions for efficient organic contaminant removal under neutral conditions

Abstract

Homogeneous Fenton-like systems are usually used for treating refractory organic wastewater, while their practical application still encounters narrow pH adaptability. In this context, large amounts of acid reagents are indispensable to ensure the high catalysis efficiency, which makes the whole arduous and expensive. Herein, we proposed a promising strategy of “localized proton enrichment” (LPE) for broadening the pH adaptability of heterogeneous catalysts. By utilizing S sites of metal sulfide as the “proton shuttle”, H⁺ can be enriched from bulk solution to the local catalytic Fe center, which is expected to overcome the pH limitation of conventional Fenton-like reactions. As a result, the as-constructed catalyst (Fe-MoS₂NF) demonstrated excellent degradation performance within a wide pH range of 3.0–9.0. Compared with the conventional Fenton process catalyzed by Fe²⁺, Fe-MoS₂NF exhibited more than 8.0-fold increment in pollutant removal performance under neutral condition. Based on this, the reaction promotion mechanisms of LPE effect were systematically explored. Furthermore, a scale-up catalytic system was established by immobilizing the powdery Fe-MoS₂NF on a robust sponge skeleton, which indicates its significant potential in industrial application. Our work provides a universal and effective approach for overcoming the challenges encountered in the traditional Fenton process under neutral conditions.