One of vital issues that inhibit photoactivity of metal-organic frameworks is the poor electrical conductivity. In this work, one-dimensional mixed-valence iron chains are used to improve this poor situation in MIL-53(Fe). A series of mixed-valence MIL-53(Fe) photocatalysts were obtained through heating at different temperatures in vacuum. The effect of Fe coordinatively unsaturated metal sites (CUS) and one-dimensional mixed-valence iron chains on their photocatalytic property was discussed. The experimental results indicated that mixed-valence MIL-53(Fe) with a reference Fe/Fe ratio of 0.2725 displayed the best photocatalytic performance, which showed 96.28 and 95.01% removal efficiencies of RhB and TC-H in 100 min, respectively. Moreover, MIL-53(Fe) heated in vacuum displayed better catalytic activity than MIL-53(Fe) heated in air for RhB and TC-H degradation. Based on the analysis of various characterizations, the reinforced catalytic activity can be attributed to the charge mobilities in mixed-valence Fe/Fe chains. It is worth mentioning that the method is also applicable to MIL-88(Fe) and MIL-101(Fe). Additionally, mixed-valence MIL-53(Fe) can also perform the catalysis reaction in the nighttime by activating persulfate (PS) to produce free radicals. Interestingly, it was found that the Fe CUS lost in activating PS can be supplemented by self-reduction of photogenerated electrons during illumination in the daytime, so as to achieve a more stable cycle. This work demonstrated that the photoactivity of MIL-53(Fe) can be improved by adjusting the ratio of Fe/Fe and the feasibility of using as an all-day-active catalyst.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsami.9b05829 | DOI Listing |
Chem Soc Rev
December 2024
Department of Chemistry, Faculty of Sciences, Tarbiat Modares University, PO Box 14115-4838, Tehran, Islamic Republic of Iran.
Owing to increasing global demand for the development of multifunctional advanced materials with various practical applications, great attention has been paid to metal-organic frameworks due to their unique properties, such as structural, chemical, and functional diversity. Several strategies have been developed to promote the applicability of these materials in practical fields. The induction of mixed-valency is a promising strategy, contributing to exceptional features in these porous materials such as enhanced charge delocalization, conductivity, magnetism, The current review provides a detailed study of mixed-valence MOFs, including their fundamental properties, synthesis challenges, and characterization methods.
View Article and Find Full Text PDFTalanta
December 2024
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, China. Electronic address:
In this study, we used meso-tetra (4-carboxyphenyl) porphyrin (TCPP) as an organic ligand to modify a lanthanide-based metal-organic framework as an electrochemiluminescence (ECL) platform to sensitively detect anti-Müllerian hormone (AMH). La-MOF amplified the ECL signal by suppressing the aggregation-caused quenching created by TCPP self-aggregation. Utilizing the reversible cycling of the mixed-valence transition metal ion (Cu/Cu and Mo/Mo) and the electrical conductivity of CuMoS and silver nanoparticle (AgNP), CuMoS-AgNP as a dual co-reaction promoter constantly generated sulfate radical anions (SO) and thus amplified the ECL signal.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517619, India.
Cyclic alkyl(amino) carbene (cAAC)-supported phosphaalkenides (cAACP) have been employed as ligands for the isolation of two atomically precise mixed valence paramagnetic AgI/012Cl, and AgI/010, nano-clusters [(Me-cAACP)AgCl] (2), and [(Me-cAACP)Ag](NTf) (4). 2 and 4 have been structurally characterized by single-crystal X-ray diffraction revealing the presence of three Ag atoms, nine Ag ions (2); and two Ag atoms, eight Ag ions (4), respectively. The clustering inorganic unit AgCl in 2 has been found to be surrounded by six mono-anionic μ-cAACP moieties having 3-bar symmetry.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
Programming and synthesizing bifunctional materials for regulating the output of triboelectric nanogenerators (TENGs) and their photocatalytic efficiency is a promising strategy for energy harvesting to build self-powered systems. Herein, we tackle this challenge by introducing metal-organic frameworks (MOFs) as molecular catalysts and triboelectric layers for self-powered photocatalytic systems. A zeolite-like mixed-valence MOF () and a ladder-structured MOF () were obtained through structural transformation.
View Article and Find Full Text PDFTalanta
December 2024
Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Anhui Province Industrial Generic Technology Research Center for Alumics Materials, School of Physics and Electronic Information, Huaibei Normal University, Huaibei, 235000, PR China. Electronic address:
Transition metal oxides (TMOs) can effectively improve the performance of electrochemical detection due to their unique electronic structure and redox properties. However, the lack of reproducibility and the electrical activity of TMOs prepared from conventional preparation methods limit their further development. In this work, amorphous MoO with reductive Mo(V) was successfully synthesized by one-step electrodeposition, and it has excellent detection performance for p-nitrophenol (PNP).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!