Abstract
Classical Metal-Organic Frameworks (MOFs), although able to accumulate chemicals from solution, are usually electrochemically “inactive”. Here, it is demonstrated for the zinc-containing MOF-5(Zn) (and MOF-5W(Zn)) system, that silver incorporation (Ag@MOF-5(Zn), prepared via a solvothermal process) can be used to assist/promote release and electrochemical oxidation of accumulated nitrophenols (2-methyl-4-nitrophenol, 4-nitrophenol, and 2-nitrophenol). Nitrophenols belong to a group of compounds that are present in diesel exhaust and considered harmful pollutants. The enhanced electrochemical detection of nitrophenols at a glassy carbon electrode modified with Ag@MOF-5(Zn) is suggested to be due to analyte accumulation with estimated Langmuirian binding constants of 40 × 10 3 M −1 (for 2-methyl-4-nitrophenol and 4-nitrophenol) and 15 × 10 3 M −1 (for 2-nitrophenol) and electrochemical detection/conversion with a current enhancement of more than one order of magnitude due to potential driven release from Ag@MOF-5(Zn). Surface characterization and electrochemical techniques suggest that silver is present in Ag@MOF-5(Zn) in metallic form and probably also embedded into the framework. This silver incorporation changes the electrochemical oxidation behavior towards nitrophenols in MOF-5(Zn) from “inactive” to “active”. The new class of metal@MOF materials is highlighted as practical nano-composites.
Original language | English |
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Pages (from-to) | 482-491 |
Number of pages | 10 |
Journal | Electrochimica Acta |
Volume | 219 |
Early online date | 4 Oct 2016 |
DOIs | |
Publication status | Published - 20 Nov 2016 |
Funding
We are grateful for the financial support from CSIR (01(2708)/13/EMR-II) and UGC (42-271/2013 (SR)), New Delhi is acknowledged gratefully. DKY acknowledges UGC for the junior research fellowship (JRF). We thank Prof. O. N. Srivastava, Banaras Hindu University for TEM studies and Dr. S. A. John, Gandhigram Rural University for SEM and EDAX studies.
Keywords
- electrocatalysis
- environmental pollutant
- microporosity
- nitrophenol
- promotor
ASJC Scopus subject areas
- General Chemical Engineering
- Electrochemistry