Reconstruction of Electronic Structure of MOF-525 via Metalloporphyrin for Enhanced Photoelectro-Fenton Process

Abstract

Photoelectro-Fenton (PEF) process can continuously promote the occurrence of Fenton reaction and the generation of active species, which is an advanced oxidation technology for pollutant degradation. However, the lack of bifunctional catalysts restricts the development of PEF technology. In this study, the electronic rearrangement MOF-525 modified by metalloporphyrin (named MOF-525-Fe/Zr) was prepared, to load on the carbon felt as a novel cathode catalyst, which is used in PEF process. A series of characterization and photoelectric chemical properties tests combined with DFT calculation showed that the modification of MOF-525 could not only have the large specific surface area and multistage pore structure but also co-stimulate the metal-to-ligand charge transfer (MLCT) and ligand-to-cluster charge transfer (LCCT) by photoelectric synergy. These charge transitions provide periodic electron donor-acceptor conduction paths in MOF-525-Fe/Zr, which can improve the active species formation and transfer efficiency. Owing to their favorable pore and electronic structure as well as stability, MOF-525-Fe/Zr shows great promise for the application in the catalytic process of PEF. Sulfamethoxazole (SMX) degradation was enhanced by MOF-525-Fe/Zr with the TOC removal rate above 75% both in river water and tap water. Finally, the reasonable pathway of PEF catalytic degradation of SMX was proposed by HPLC-MS analysis. In conclusion, this study provides a new idea for reconstructing the electronic structure of MOFs catalyst and broadening the practical application of PEF technology.

Photo‐electrochemical O2 Reduction to H2O2 Using a Co‐Porphyrin Based Metal‐Organic Framework

“…Additionally, Scanning Electron Microscopy (SEM) was used to determine the morphology of the powder sample, revealing the typical cubic‐shaped of MOF‐525 with an average particle size of ~1 μm (Figure S1b). N 2 physisorption isotherm analyzes reveal the porous structure of Co‐MOF‐525, a BET surface area of 2117.902 m 2 /g (Figure S2a) and BJH pore size distribution in the mesoporous region within the range of 1–1.7 nm,, which are in good agreement with previous reports (Figure S2b) [27–28] …”

“…N 2 physisorption isotherm analyzes reveal the porous structure of Co-MOF-525, a BET surface area of 2117.902 m 2 /g (Figure S2a) and BJH pore size distribution in the mesoporous region within the range of 1-1.7 nm,, which are in good agreement with previous reports (Figure S2b). [27][28] Inductively coupled plasma (ICP) analysis was used to characterize the Co content in the MOF sample, revealing a Zr 6 : Co atomic ratio of 1 : 2.53, indicating that 84.2 % of the H 2 TPP linkers were metallated with cobalt (Table S1).…”

Metal–Organic Frameworks as Powerful Heterogeneous Catalysts in Advanced Oxidation Processes for Wastewater Treatment

“…To improve this hybrid process, it is important the selection of a good photoelectric catalysis performance since it determines the additional generation of these radicals [205]. A Fe-O cluster, which is photosensitive, is also an advantage of Fe-MOFs in the photoelectro-Fenton process, as discussed in Section 4.2.…”

“…A Fe-O cluster, which is photosensitive, is also an advantage of Fe-MOFs in the photoelectro-Fenton process, as discussed in Section 4.2. The studies of Qi et al [205] and Du et al [206] should be emphasized due to their incorporation of new bimetallic Fe-MOFs within the photo-electro-Fenton processes. Regarding the study of Qi et al [205], MOF-525-Fe/Zr is synthesized and with this MOF the CF is coated to fabricate the modified cathode, which is called MOF-525-Fe/Zr@CF.…”

“…The studies of Qi et al [205] and Du et al [206] should be emphasized due to their incorporation of new bimetallic Fe-MOFs within the photo-electro-Fenton processes. Regarding the study of Qi et al [205], MOF-525-Fe/Zr is synthesized and with this MOF the CF is coated to fabricate the modified cathode, which is called MOF-525-Fe/Zr@CF. When carrying out the characterization study of this material, the main difference between MOF-525 and MOF-525-Fe/Zr is the large increase in pore area and pore volume.…”