Confining Free Radicals in Close Vicinity to Contaminants Enables Ultrafast Fenton-like Processes in the Interspacing of MoS2 Membranes

摘要

Heterogenous Fenton-like reactions are frequently proposed for treating persistent pollutants through the generation of reactive radicals. Despite great efforts to optimize catalyst activity, their broad application in practical settings has been restricted by the low efficiency of hydrogen peroxide or persulfate decomposition as well as ultrafast self-quenching of the activated radicals. Theoretical calculations predicted that two-dimensional (2D) metallic 1T phase MoS2 materials with exposed (001) surfaces and (100) edges should have remarkable affinity towards crucial intermediates in the peroxymonosulfate (PMS) activation process. X-ray photoelectron spectroscopy and in situ Raman spectroscopy were used to show that the exposed metallic Mo sites accelerate the rate-limiting step of electron transfer. A lamellar membrane made from a stack of 2D MoS2 with tunable interspacing was then designed as the catalyst. The non-linear transport between the MoS2 nanolayers leads to high water diffusivity so that the short-lived reactive radicals efficiently oxidize contaminants.