Effects and Mechanisms of Cu Species in Fe-MOFs on Fenton-Like Catalytic Activity and Stability

Abstract

Fe-based MOFs (Fe-MOFs) are deemed promising Fenton-like catalysts due to their well-developed pores and accessible active sites. However, their inferior catalytic activity, iron leaching, and low H2O2 utilization always hinder their application as Fe-based MOF catalysts. In this work, we manipulated the structure of Fe-oxo nodes in MIL-88B(Fe) via a CuI species substitution method, affording a mixed-valence (Cu-incorporated Fe-MOFs) with highly improved Fenton-like performance. It is found that the CuI serves as a shuttle to promote transfer between FeII/FeIII, inducing the formation of a larger amount of stable FeII sites, which was proven by experimental and DFT calculation results. A linear relationship was observed for the Fenton-like performance and the amount of CuI species for the catalysts. The corresponding value of the •OH formation is 2.17 eV for Cu-incorporated MIL-88B(Fe), which is significantly lower than that of MIL-88B(Fe) (2.69 eV). Meanwhile, the enriched CuI species suppress Fe species leaching during the catalytic reaction. The Fe-ion leakage of 0.4Cu@MIL-88B is very tiny (0.01–0.03 mg/L), significantly less than that of MIL-88B (2.00–3.02 mg/L). At the same time, H2O2 utilization for 0.4Cu@ MIL-88B(Fe) is 88%, which is almost 4.4 times that of pure MIL-88B(Fe). This work provides insights into the rational design of Fe-MOFs as promising Fenton-like catalysts for wastewater treatment.

Fe–Co-Based Metal–Organic Frameworks as Peroxidase Mimics for Sensitive Colorimetric Detection and Efficient Degradation of Aflatoxin B1

“…In recent years, peroxidase-like mimics have also been intensively employed in the field of advanced oxidative degradation of various pollutants in addition to sensing. , In particular, Fe-based MOF materials can act as Fenton-like catalysts to promote hydrogen peroxide to rapidly generate a large number of free radicals, so as to achieve efficient oxidative degradation of pollutants. − To expand the application of Fe–Co-MOFs, the Fenton-like catalytic degradation properties of Fe–Co-MOFs were exploited in this section.…”

Application of Fe-MOFs in Photodegradation and Removal of Air and Water Pollutants: A Review

“…Tang et al [97] accomplished the degradation of ibuprofen by anchoring ReS 2 nanoparticles in a heterojunction formed in MIL-88B (Fe) under visible light and persulfate (PS). Song et al [98] obtained mixed-valent Cu@MIL-88B(Fe) after processing the Fe-oxo node structure in MIL-88B(Fe) by the Cu + species substitution method. Both experimental and computational results showed that Cu + played a shuttling role in promoting the transfer between Fe 2+ /Fe 3+ and inducing the formation of a large number of stable Fe 2+ sites, as well as suppressing the leaching of iron ions during the catalytic process.…”