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Kozłowska K, Cieślik M, Koterwa A, Formela K, Ryl J, Niedziałkowski P. Microwave-Induced Processing of Free-Standing 3D Printouts: An Effortless Route to High-Redox Kinetics in Electroanalysis. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2833. [PMID: 38930201 PMCID: PMC11204644 DOI: 10.3390/ma17122833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 05/21/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024]
Abstract
3D-printable composites have become an attractive option used for the design and manufacture of electrochemical sensors. However, to ensure proper charge-transfer kinetics at the electrode/electrolyte interface, activation is often required, with this step consisting of polymer removal to reveal the conductive nanofiller. In this work, we present a novel effective method for the activation of composites consisting of poly(lactic acid) filled with carbon black (CB-PLA) using microwave radiation. A microwave synthesizer used in chemical laboratories (CEM, Matthews, NC, USA) was used for this purpose, establishing that the appropriate activation time for CB-PLA electrodes is 15 min at 70 °C with a microwave power of 100 W. However, the usefulness of an 80 W kitchen microwave oven is also presented for the first time and discussed as a more sustainable approach to CB-PLA electrode activation. It has been established that 10 min in a kitchen microwave oven is adequate to activate the electrode. The electrochemical properties of the microwave-activated electrodes were determined by electrochemical techniques, and their topography was characterized using scanning electron microscopy (SEM), Raman spectroscopy, and contact-angle measurements. This study confirms that during microwave activation, PLAs decompose to uncover the conductive carbon-black filler. We deliver a proof-of-concept of the utility of kitchen microwave-oven activation of a 3D-printed, free-standing electrochemical cell (FSEC) in paracetamol electroanalysis in aqueous electrolyte solution. We established satisfactory limits of linearity for paracetamol detection using voltammetry, ranging from 1.9 μM to 1 mM, with a detection limit (LOD) of 1.31 μM.
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Affiliation(s)
- Kornelia Kozłowska
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdansk, Poland; (K.K.); (M.C.); (A.K.)
| | - Mateusz Cieślik
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdansk, Poland; (K.K.); (M.C.); (A.K.)
- Institute of Nanotechnology and Materials Engineering, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Adrian Koterwa
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdansk, Poland; (K.K.); (M.C.); (A.K.)
| | - Krzysztof Formela
- Department of Polymer Technology, Faculty of Chemistry, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland;
- Advanced Materials Center, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Jacek Ryl
- Institute of Nanotechnology and Materials Engineering, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland
- Advanced Materials Center, Gdańsk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Paweł Niedziałkowski
- Department of Analytical Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdansk, Poland; (K.K.); (M.C.); (A.K.)
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2
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Murtaza A, Ulhaq Z, Shirinfar B, Rani S, Aslam S, Martins GM, Ahmed N. Arenes and Heteroarenes C-H Functionalization Under Enabling Conditions: Electrochemistry, Photoelectrochemistry & Flow Technology. CHEM REC 2023; 23:e202300119. [PMID: 37255348 DOI: 10.1002/tcr.202300119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/18/2023] [Indexed: 06/01/2023]
Abstract
C-H bond functionalization generates molecular complexity in single-step transformation. However, the activation of C-H bonds requires expensive metals or stoichiometric amounts of oxidizing/reducing species. In many cases, they often require pre-functionalization of starting molecules. Such pre-activating measures cause waste generation and their separation from the final product is also troublesome. In such a scenario, reactions activating elements generating from renewable energy resources such as electricity and light would be more efficient, green, and cost-effective. Further, incorporation of growing flow technology in chemical transformation processes will accelerate the safer accesses of valuable products. Arenes & heteroarenes are ubiquitous in pharmaceuticals, natural products, medicinal compounds, and other biologically important molecules. Herein, we discussed enabling tools and technologies used for the recent C-H bonds functionalization of arenes and heteroarenes.
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Affiliation(s)
- Ayesha Murtaza
- Department of Chemistry, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Zia Ulhaq
- Chemical Engineering Department, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Bahareh Shirinfar
- Department of Chemistry, University of Bath, BA2 7AY, Bath, United Kingdom
- West Herts College, Hertfordshire, Watford, WD17 3EZ, London, United Kingdom
| | - Sadia Rani
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Samina Aslam
- Department of Chemistry, The Women University Multan, Multan, 60000, Pakistan
| | - Guilherme M Martins
- Department of Chemistry, Federal University of Sao Carlos - UFS Car, 13565-905, São Carlos -SP, Brazil
- School of Chemistry, Cardiff University, Main Building Park Place, Cardiff, CF10 3AT, United Kingdom
| | - Nisar Ahmed
- School of Chemistry, Cardiff University, Main Building Park Place, Cardiff, CF10 3AT, United Kingdom
- Centre for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, University of Karachi, Karachi, 75270, Pakistan
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Tsubaki S, Matsuzawa T, Suzuki E, Fujii S, Wada Y. Operando Raman Spectroscopy of the Microwave-Enhanced Catalytic Dehydration of 2-Propanol by WO 3. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.9b03876] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shuntaro Tsubaki
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1 E4-3, Meguro, Tokyo 152-8550, Japan
| | - Tomoki Matsuzawa
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1 E4-3, Meguro, Tokyo 152-8550, Japan
| | - Eiichi Suzuki
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1 E4-3, Meguro, Tokyo 152-8550, Japan
| | - Satoshi Fujii
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1 E4-3, Meguro, Tokyo 152-8550, Japan
- Department of Information and Communication Systems Engineering, Okinawa National College of Technology, 905 Henoko, Nago-shi 905-2192, Okinawa, Japan
| | - Yuji Wada
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1 E4-3, Meguro, Tokyo 152-8550, Japan
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5
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Microwave Enthrakometric Labs-On-A-Chip and On-Chip Enthrakometric Catalymetry: From Non-Conventional Chemotronics Towards Microwave-Assisted Chemosensors. CHEMOSENSORS 2019. [DOI: 10.3390/chemosensors7040048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A unique chemical analytical approach is proposed based on the integration of chemical radiophysics with electrochemistry at the catalytically-active surface. This approach includes integration of: radiofrequency modulation polarography with platinum electrodes, applied as film enthrakometers for microwave measurements; microwave thermal analysis performed on enthrakometers as bolometric sensors; catalytic measurements, including registration of chemical self-oscillations on the surface of a platinum enthrakometer as the chemosensor; measurements on the Pt chemosensor implemented as an electrochemical chip with the enthrakometer walls acting as the chip walls; chemotron measurements and data processing in real time on the surface of the enthrakometric chip; microwave electron paramagnetic resonance (EPR) measurements using an enthrakometer both as a substrate and a microwave power meter; microwave acceleration of chemical reactions and microwave catalysis оn the Pt surface; chemical generation of radio- and microwaves, and microwave spin catalysis; and magnetic isotope measurements on the enthrakometric chip. The above approach allows one to perform multiparametric physical and electrochemical sensing on a single active enthrakometric surface, combining the properties of the selective electrochemical sensor and an additive physical detector.
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Yang S, Chen X, Mi ZZ, Chen ZM, Li XD, Sun JJ, Wu SH. Temperature-Controllable Electrodes with a One-Parameter Calibration. ACS Sens 2019; 4:1594-1602. [PMID: 31148452 DOI: 10.1021/acssensors.9b00297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Electrically heated electrodes have been applied for various chemical and biological sensors. However, previous electrically heated electrodes, including microwires and microdiscs, are usually small and often suffer from the requirement of frequent calibrations of the electrode surface temperature ( Ts) at different environment temperatures. Here, we fabricate a temperature-controllable disk electrode (TCDE) with a conventional size (3-5 mm in diameter). A one-parameter temperature calibration is proposed using a temperature transfer coefficient α and a structural model ( Ts = Te + α ( Th - Te)) to estimate Ts ( Th and Te are the temperature of the heating element and environment, respectively). The value of α is unique for a TCDE and mainly dependent on the structure and materials of the electrodes and the solution in nature. Once α is experimentally determined, Ts can be calibrated and found to be applicable to wide fluctuations in room temperature (15.0-33.0 °C) with errors below 1.5% for three types of disk electrodes (gold, glassy carbon, and platinum). The required Ts can be obtained by just setting Th without thermal characterization between the heating power and Ts. A simple relationship for exploring the dependence of α on the height ( H) and radius ( R) of the electrode materials and other constants ( a, b, c, and R0), α = 1 - c - aH - b ( R - R0)2, is revealed by numerical simulations (COMSOL). The impact of the radii of both the insulating materials of the electrode and the electrochemical cells on Ts is also considered. The effect of the solution thermal conductivity on α is studied. TCDEs are expected to be used as a sensor platform with enhanced performance.
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Affiliation(s)
- Sen Yang
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Xing Chen
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Zhen-Zhen Mi
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Zhi-Min Chen
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Xiao-Dong Li
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Jian-Jun Sun
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Shao-Hua Wu
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China
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Jiang X, Lin Z, Zeng X, He J, Xu F, Deng P, Jia J, Jiang X, Hou X, Long Z. Plasma-catalysed reaction Mn+ + L–H → MOFs: facile and tunable construction of metal–organic frameworks in dielectric barrier discharge. Chem Commun (Camb) 2019; 55:12192-12195. [DOI: 10.1039/c9cc06795g] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A fast, energy-saving and green strategy was proposed for preparing diverse and fine-tuned metal–organic frameworks in either DMF or ethanol, catalyzed by liquid-phase plasma generated via dielectric barrier discharge.
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Affiliation(s)
- Xue Jiang
- Key Laboratory of Green Chemistry & Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064
- China
| | - Zhi'en Lin
- Key Laboratory of Green Chemistry & Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064
- China
| | - Xiaoliang Zeng
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
| | - Juan He
- Key Laboratory of Green Chemistry & Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064
- China
| | - Fujian Xu
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
| | - Pengchi Deng
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
| | - Jia Jia
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
| | - Xiaoming Jiang
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
| | - Xiandeng Hou
- Key Laboratory of Green Chemistry & Technology (Ministry of Education)
- College of Chemistry
- Sichuan University
- Chengdu 610064
- China
| | - Zhou Long
- Analytical & Testing Center
- Sichuan University
- Chengdu 610064
- China
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8
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Tsubaki S, Hayakawa S, Ueda T, Fujii S, Suzuki EI, Zhang J, Bond A, Wada Y. Radio frequency alternating electromagnetic field enhanced tetraruthenium polyoxometalate electrocatalytic water oxidation. Chem Commun (Camb) 2019; 55:1032-1035. [DOI: 10.1039/c8cc07642a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
RF-enhanced electrocatalytic water oxidation by protonated tetraruthenium polyoxometalate.
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Affiliation(s)
- Shuntaro Tsubaki
- School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
| | - Shogo Hayakawa
- School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
| | - Tadaharu Ueda
- Department of Marine Resource Science
- Faculty of Agriculture and Marine Science
- Kochi University
- Nankoku
- Japan
| | - Satoshi Fujii
- School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
- Department of Information and Communication Systems Engineering
| | - Ei-ichi Suzuki
- School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
| | - Jie Zhang
- School of Chemistry
- Monash University
- Clayton
- Victoria 3800
- Australia
| | - Alan Bond
- School of Chemistry
- Monash University
- Clayton
- Victoria 3800
- Australia
| | - Yuji Wada
- School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
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9
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Gandhi M, Rajagopal D, Parthasarathy S, Raja S, Huang ST, Senthil Kumar A. In Situ Immobilized Sesamol-Quinone/Carbon Nanoblack-Based Electrochemical Redox Platform for Efficient Bioelectrocatalytic and Immunosensor Applications. ACS OMEGA 2018; 3:10823-10835. [PMID: 30320253 PMCID: PMC6173515 DOI: 10.1021/acsomega.8b01296] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 08/22/2018] [Indexed: 05/22/2023]
Abstract
Most of the common redox mediators such as organic dyes and cyanide ligand-associated metal complex systems that have been used for various electrochemical applications are hazardous nature. Sesamol, a vital nutrient that exists in natural products like sesame seeds and oil, shows several therapeutic benefits including anticancer, antidiabetic, cardiovascular protective properties, etc. Herein, we introduce a new electrochemical redox platform based on a sesamol derivative, sesamol-quinone (Ses-Qn; oxidized sesamol), prepared by the in situ electrochemical oxidation method on a carbon nanoblack chemically modified glassy carbon electrode surface (GCE/CB@Ses-Qn) in pH 7 phosphate buffer solution, for nontoxic and sustainable electrochemical, electroanalytical, and bioelectroanalytical applications. The new Ses-Qn-modified electrode showed a well-defined redox peak at E o = 0.1 V vs Ag/AgCl without any surface-fouling behavior. Following three representative applications were demonstrated with this new redox system: (i) simple and quick estimation of sesamol content in the natural herbal products by electrochemical oxidation on GCE/CB followed by analyzing the oxidation current signal. (ii) Utilization of the GCE/CB@Ses-Qn as a transducer, bioelectrocatalytic reduction, and sensing of H2O2 after absorbing the horseradish peroxidase (HRP)-based enzymatic system on the underlying surface. The biosensor showed a highly selective H2O2 signal with current sensitivity and detection limit values 0.1303 μA μM-1 and 990 nM, respectively, with tolerable interference from the common biochemicals like dissolved oxygen, cysteine, ascorbic acid, glucose, xanthine, hypoxanthine, uric acid, and hydrazine. (iii) Electrochemical immunosensing of white spot syndrome virus by sequentially modifying primary antibody, antigen, secondary antibody (HRP-linked), and bovine serum albumin on the redox electrode, followed by selective bioelectrochemical detection of H2O2.
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Affiliation(s)
- Mansi Gandhi
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
| | - Desikan Rajagopal
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
- Burnett
School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827, United States
- E-mail: , . Phone: +1-407
590 3978, +91-416-2202330 (D.R.)
| | - Sampath Parthasarathy
- Burnett
School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827, United States
| | - Sudhakaran Raja
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
| | - Sheng-Tung Huang
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
| | - Annamalai Senthil Kumar
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
- E-mail: , . Phone: +91-416-2202754 (A.S.K.)
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Díaz‐Ortiz Á, Prieto P, de la Hoz A. A Critical Overview on the Effect of Microwave Irradiation in Organic Synthesis. CHEM REC 2018; 19:85-97. [DOI: 10.1002/tcr.201800059] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/05/2018] [Indexed: 01/24/2023]
Affiliation(s)
- Á. Díaz‐Ortiz
- Departamento de Química OrgánicaUniversidad de Castilla-La ManchaFacultad de Ciencias y Tecnologías Químicas. Instituto Regional deInvestigación Científica Aplicada (IRICA) Avda. Camilo José Cela, s/n E. 13071 Ciudad Real
| | - P. Prieto
- Departamento de Química OrgánicaUniversidad de Castilla-La ManchaFacultad de Ciencias y Tecnologías Químicas. Instituto Regional deInvestigación Científica Aplicada (IRICA) Avda. Camilo José Cela, s/n E. 13071 Ciudad Real
| | - A. de la Hoz
- Departamento de Química OrgánicaUniversidad de Castilla-La ManchaFacultad de Ciencias y Tecnologías Químicas. Instituto Regional deInvestigación Científica Aplicada (IRICA) Avda. Camilo José Cela, s/n E. 13071 Ciudad Real
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11
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Kishimoto F, Leong KH, Kawamura S, Haneishi N, Tsubaki S, Wada Y. Acceleration of Water Electrolysis by Accumulation of Microwave Energy at a Pt Disk Electrode. CHEM LETT 2017. [DOI: 10.1246/cl.170686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Fuminao Kishimoto
- Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-E4-3 Ookayama, Meguro, Tokyo 152-8552
| | - Kah Hon Leong
- Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak, Malaysia
| | - Shinichiro Kawamura
- Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-E4-3 Ookayama, Meguro, Tokyo 152-8552
| | - Naoto Haneishi
- Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-E4-3 Ookayama, Meguro, Tokyo 152-8552
| | - Shuntaro Tsubaki
- School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1-E4-3 Ookayama, Meguro, Tokyo 152-8552
| | - Yuji Wada
- School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1-E4-3 Ookayama, Meguro, Tokyo 152-8552
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12
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13
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Kishimoto F, Matsuhisa M, Kawamura S, Fujii S, Tsubaki S, Maitani MM, Suzuki E, Wada Y. Enhancement of anodic current attributed to oxygen evolution on α-Fe 2O 3 electrode by microwave oscillating electric field. Sci Rep 2016; 6:35554. [PMID: 27739529 PMCID: PMC5064412 DOI: 10.1038/srep35554] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/28/2016] [Indexed: 01/15/2023] Open
Abstract
Various microwave effects on chemical reactions have been observed, reported and compared to those carried out under conventional heating. These effects are classified into thermal effects, which arise from the temperature rise caused by microwaves, and non-thermal effects, which are attributed to interactions between substances and the oscillating electromagnetic fields of microwaves. However, there have been no direct or intrinsic demonstrations of the non-thermal effects based on physical insights. Here we demonstrate the microwave enhancement of oxidation current of water to generate dioxygen with using an α-Fe2O3 electrode induced by pulsed microwave irradiation under constantly applied potential. The rectangular waves of current density under pulsed microwave irradiation were observed, in other words the oxidation current of water was increased instantaneously at the moment of the introduction of microwaves, and stayed stably at the plateau under continuous microwave irradiation. The microwave enhancement was observed only for the α-Fe2O3 electrode with the specific surface electronic structure evaluated by electrochemical impedance spectroscopy. This discovery provides a firm evidence of the microwave special non-thermal effect on the electron transfer reactions caused by interaction of oscillating microwaves and irradiated samples.
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Affiliation(s)
- Fuminao Kishimoto
- Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology. E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan.,Research Fellow of Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan
| | - Masayuki Matsuhisa
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Shinichiro Kawamura
- Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology. E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Satoshi Fujii
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan.,Department of Information and Communication Systems Engineering, Okinawa National College of Technology, 905 Henoko, Nago-shi, Okinawa 905-2192, Japan
| | - Shuntaro Tsubaki
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Masato M Maitani
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Eiichi Suzuki
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Yuji Wada
- Department of chemical science and engineering, School of materials and chemical technology, Tokyo Institute of Technology, E4-3, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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14
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A model for understanding the temperature change of an alternate hot and cold micro-band graphite electrode. Electrochem commun 2016. [DOI: 10.1016/j.elecom.2016.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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15
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Ano T, Kishimoto F, Sasaki R, Tsubaki S, Maitani MM, Suzuki E, Wada Y. In situ temperature measurements of reaction spaces under microwave irradiation using photoluminescent probes. Phys Chem Chem Phys 2016; 18:13173-9. [PMID: 27136754 DOI: 10.1039/c6cp02034h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We demonstrate two novel methods for the measurement of the temperatures of reaction spaces locally heated by microwaves, which have been applied here to two example systems, i.e., BaTiO3 particles covered with a SiO2 shell (BaTiO3-SiO2) and layered tungstate particles. Photoluminescent (PL) probes showing the temperature-sensitivity in their PL lifetimes are located in the nanospaces of the above systems. In the case of BaTiO3-SiO2 core-shell particles, rhodamine B is loaded into the mesopores of the SiO2 shell covering the BaTiO3 core, which generates the heat through the dielectric loss of microwaves. The inner nanospace temperature of the SiO2 shell is determined to be 28 °C higher than the bulk temperature under microwave irradiation at 24 W. On the other hand, Eu(3+) is immobilized in the interlayer space of layered tungstate as the PL probe, showing that the nanospace temperature of the interlayer is only 4 °C higher than the bulk temperature. This method for temperature-measurement is powerful for controlling microwave heating and elucidates the ambiguous mechanisms of microwave special effects often observed in chemical reactions, contributing greatly to the practical application of microwaves in chemistry and materials sciences.
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Affiliation(s)
- Taishi Ano
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Fuminao Kishimoto
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Ryo Sasaki
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Shuntaro Tsubaki
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Masato M Maitani
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Eiichi Suzuki
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
| | - Yuji Wada
- Department of Applied Chemistry, Tokyo Institute of Technology, 2-12 Ookayama, Meguro, Tokyo 152-8552, Japan.
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Cabello G, Gromboni MF, Pereira EC, Marken F. In situ microwave-enhanced electrochemical reactions at stainless steel: Nano-iron for aqueous pollutant degradation. Electrochem commun 2016. [DOI: 10.1016/j.elecom.2015.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Rodríguez AM, Prieto P, de la Hoz A, Díaz-Ortiz Á, Martín DR, García JI. Influence of Polarity and Activation Energy in Microwave-Assisted Organic Synthesis (MAOS). ChemistryOpen 2015; 4:308-17. [PMID: 26246993 PMCID: PMC4522181 DOI: 10.1002/open.201402123] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Indexed: 01/28/2023] Open
Abstract
The aim of this work was to determine the parameters that have decisive roles in microwave-assisted reactions and to develop a model, using computational chemistry, to predict a priori the type of reactions that can be improved under microwaves. For this purpose, a computational study was carried out on a variety of reactions, which have been reported to be improved under microwave irradiation. This comprises six types of reactions. The outcomes obtained in this study indicate that the most influential parameters are activation energy, enthalpy, and the polarity of all the species that participate. In addition to this, in most cases, slower reacting systems observe a much greater improvement under microwave irradiation. Furthermore, for these reactions, the presence of a polar component in the reaction (solvent, reagent, susceptor, etc.) is necessary for strong coupling with the electromagnetic radiation. We also quantified that an activation energy of 20-30 kcal mol(-1) and a polarity (μ) between 7-20 D of the species involved in the process is required to obtain significant improvements under microwave irradiation.
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Affiliation(s)
- Antonio M Rodríguez
- Departamento de Química Orgánica, Universidad de Castilla–La Mancha, Facultad de Ciencias y Tecnologías Químicas13071, Ciudad Real, Spain
| | - Pilar Prieto
- Departamento de Química Orgánica, Universidad de Castilla–La Mancha, Facultad de Ciencias y Tecnologías Químicas13071, Ciudad Real, Spain
| | - Antonio de la Hoz
- Departamento de Química Orgánica, Universidad de Castilla–La Mancha, Facultad de Ciencias y Tecnologías Químicas13071, Ciudad Real, Spain
| | - Ángel Díaz-Ortiz
- Departamento de Química Orgánica, Universidad de Castilla–La Mancha, Facultad de Ciencias y Tecnologías Químicas13071, Ciudad Real, Spain
| | - D Raúl Martín
- Departamento de Química Orgánica, Universidad de Castilla–La Mancha, Facultad de Ciencias y Tecnologías Químicas13071, Ciudad Real, Spain
| | - José I García
- Departamento de Química Orgánica, Instituto de Síntesis Química y Catálisis Homogénea, CSIC-Universidad de ZaragozaC/. Pedro Cerbuna, 12, 50009, Zaragoza, Spain
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Mochizuki D, Sasaki R, Maitani MM, Okamoto M, Suzuki E, Wada Y. Catalytic reactions enhanced under microwave-induced local thermal non-equilibrium in a core–shell, carbon-filled zeolite@zeolite. J Catal 2015. [DOI: 10.1016/j.jcat.2014.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Alam MJ, Ahmad S. Molecular structure, anharmonic vibrational analysis and electronic spectra of o-, m-, p-iodonitrobenzene using DFT calculations. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2013.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Flechsig GU, Walter A. Electrically Heated Electrodes: Practical Aspects and New Developments. ELECTROANAL 2011. [DOI: 10.1002/elan.201100412] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zhao G, Gao J, Shi W, Liu M, Li D. Electrochemical incineration of high concentration azo dye wastewater on the in situ activated platinum electrode with sustained microwave radiation. CHEMOSPHERE 2009; 77:188-193. [PMID: 19683784 DOI: 10.1016/j.chemosphere.2009.07.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 05/28/2023]
Abstract
In this study, an in situ microwave activated platinum electrode was developed for the first time to completely incinerate the azo dye simulated wastewater containing methyl orange. The experiments were carried out in a circulating system under atmospheric pressure. Azo bond of methyl orange was partly broken on Pt, certain decoloration was reached, and the total organic carbon was not removed effectively without microwave activation. However, methyl orange was mineralized completely and efficiently on the in situ microwave activated Pt. 2,5-Dinitrophenol, p-nitrophenol, hydroquinone, benzoquinone, maleic and oxalic acids are the main intermediates during degradation of methyl orange. Aromatic products are the main substances leading to the poisoning of Pt and decrease of electrochemical oxidation efficiency, so methyl orange removal can not be carried out thoroughly. However, the intermediates were broke down quickly with in situ microwave activation promoting the mineralization of methyl orange on Pt.
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Affiliation(s)
- Guohua Zhao
- Department of Chemistry, Tongji University, Shanghai, China.
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Xu H, Xing S, Zeng L, Xian Y, Shi G, Jin L. Microwave-enhanced voltammetric detection of copper(II) at gold nanoparticles-modified platinum microelectrodes. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2008.10.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Rassaei L, French RW, Compton RG, Marken F. Microwave-enhanced electroanalytical processes: generator–collector voltammetry at paired gold electrode junctions. Analyst 2009; 134:887-92. [DOI: 10.1039/b900292h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Rapid formation of well-ordered self-assembled monolayers of dodecanethiol on polycrystalline gold by microwave irradiation. Electrochem commun 2008. [DOI: 10.1016/j.elecom.2008.01.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Marken F. Chemical and electro-chemical applications of in situ microwave heating. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b703986g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ghanem MA, Compton RG, Coles BA, Psillakis E, Kulandainathan MA, Marken F. Microwave activation of electrochemical processes: High temperature phenol and triclosan electro-oxidation at carbon and diamond electrodes. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.01.065] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Yao L, Du L, Ge M, Ma C, Wang D. Experimental and theoretical study of substituent effects of iodonitrobenzenes. J Phys Chem A 2007; 111:10105-10. [PMID: 17880050 DOI: 10.1021/jp073605r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The electronic structures and substituent effects of o-, m-, and p-iodonitrobenzene have been studied by ultraviolet photoelectron spectroscopy (UPS). The observed bands were interpreted on the basis of empirical arguments and theoretical calculations. The analysis of electronic effects of the donor/acceptor substituent groups is essential for the reliable assignment of the observed photoelectron spectra. The investigation of pi- and n-orbital ionization potentials enabled us to describe the correlation between substituent effects and the relative reactivities of the iodonitrobenzenes. It was found that the energy order of the pi(2) and n(II) parallel orbitals is reversed as a result of the combined influence of the electron-withdrawing nitro group and the electron-donating iodine atom. Distinct changes of the pi and n bands occur in o-iodonitrobenzene. This characteristic depends on the conjugation between the pi orbitals of the benzene ring and the nitro group and the interaction of in-plane lone pairs of iodine and one of the oxygen atoms of the nitro group in the adjacent position. This might contribute to the high reactivity of o-iodonitrobenzene in a number of reactions.
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Affiliation(s)
- Li Yao
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100080, PR China
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Wain AJ, Compton RG, Le Roux R, Matthews S, Fisher AC. Microfluidic Channel Flow Cell for Simultaneous Cryoelectrochemical Electron Spin Resonance. Anal Chem 2007; 79:1865-73. [PMID: 17269792 DOI: 10.1021/ac061910n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel microfluidic electrochemical channel flow cell has been constructed for in situ operation in a cylindrical TE011 resonant ESR cavity under variable temperature conditions. The cell has a U-tube configuration, consisting of an inlet and outlet channel which run parallel and contain evaporated gold film working, pseudo-reference, and counter electrodes. This geometry was employed to permit use in conjunction with variable temperature apparatus which does not allow a flow-through approach. The cell is characterized qualitatively and quantitatively using the one-electron reduction of p-bromonitrobenzene in acetonitrile at room temperature as a model system, and the ESR signal-flow rate response is validated by use of three-dimensional digital simulation of the concentration profile for a stable electrogenerated radical species under hydrodynamic conditions. The cell is then used to obtain ESR spectra for a number of radical species in acetonitrile at 233 K, including the radical anions of m- and p-iodonitrobenzene, o-bromonitrobenzene, and m-nitrobenzyl chloride, the latter three being unstable at room temperature. Spectra are also presented for the radical anion of 2-chloranthraquinone and the crystal violet radical, which display improved resolution at low temperatures.
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Affiliation(s)
- Andrew J Wain
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK
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Ghanem MA, Thompson M, Compton RG, Coles BA, Harvey S, Parker KH, O'Hare D, Marken F. Microwave Induced Jet Boiling Investigated via Voltammetry at Ring−Disk Microelectrodes. J Phys Chem B 2006; 110:17589-94. [PMID: 16942103 DOI: 10.1021/jp0637680] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High intensity microwave radiation is (self-)focused at metal electrodes immersed in aqueous electrolyte solutions to generate highly localized superheating and convection effects. It is shown that, for an electrode pointing downward, low intensity microwave radiation causes density driven convective flow (upward), which at the onset of boiling abruptly switches to a fast jet of liquid moving away from the electrode surface (downward). This "jet-boiling" phenomenon allows extremely high rates of mass transport and mixing to be realized at the electrode surface. Cyclic voltammograms obtained at electrodes placed into a microwave field show very strong mass transport enhancement effects. Cyclic voltammograms recorded at a Pt/Pt ring-disk electrode system (r(1) = 25 microm, r(2) = 32 microm, r(3) = 32.4 microm) in the presence of microwave radiation are employed to further explore mass transport effects under microwave conditions. Mass transport coefficients, collection efficiencies, and temperatures are determined as a function of microwave intensity.
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Ghanem M, Coles B, Compton R, Marken F. Microwave Activation of Processes in Mesopores: The Thiourea Electrooxidation at Mesoporous Platinum. ELECTROANAL 2006. [DOI: 10.1002/elan.200603490] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Horikoshi S, Tokunaga A, Watanabe N, Hidaka H, Serpone N. Environmental remediation by an integrated microwave/UV illumination technique. J Photochem Photobiol A Chem 2006. [DOI: 10.1016/j.jphotochem.2005.05.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Sur U, Marken F, Seager R, Foord J, Chatterjee A, Coles B, Compton R. Microwave Activation of Electrochemical Processes at Glassy Carbon and Boron-Doped Diamond Electrodes. ELECTROANAL 2005. [DOI: 10.1002/elan.200403171] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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40
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Banks CE, Simm AO, Bowler R, Dawes K, Compton RG. Hydrodynamic Electrochemistry: Design for a High-Speed Rotating Disk Electrode. Anal Chem 2005; 77:1928-30. [PMID: 15762607 DOI: 10.1021/ac048259d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a novel gas-driven high-speed rotating disk electrode (HSRDE). The HSRDE when immersed in an aqueous solution rotates at approximately 650 Hz, generating laminar flow resulting in a diffusion layer, under steady-state conditions, of thickness approximately 2 microm. The use of high-pressure gas to drive the rotator offers significant improvement in electrical noise as compared to conventional mechanically driven devices. The electroanalytical utility of the HSRDE was exemplified by the anodic stripping voltammetry of arsenic(III) at a gold working electrode. The charge under the arsenic stripping peak was found to increase by more than 1 order of magnitude under the enhanced mass transport regime at the HSRDE in comparison to that seen under quiescent conditions.
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Affiliation(s)
- Craig E Banks
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
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41
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Ghanem MA, Compton RG, Coles BA, Canals A, Marken F. Microwave enhanced electroanalysis of formulations: processes in micellar media at glassy carbon and at platinum electrodes. Analyst 2005; 130:1425-31. [PMID: 16172669 DOI: 10.1039/b507167d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The direct electroanalysis of complex formulations containing alpha-tocopherol (vitamin E) is possible in micellar solution and employing microwave-enhanced voltammetry. In the presence of microwave radiation substantial heating and current enhancement effects have been observed at 330 microm diameter glassy carbon electrodes placed into a micellar aqueous solution and both hydrophilic and highly hydrophobic redox systems are detected. For the water soluble Fe(CN)(6)(3-/4-) redox system in micellar aqueous solutions of 0.1 M NaCl and 0.1 M sodium dodecylsulfate (SDS) at low to intermediate microwave power, thermal effects and convection effects are observed. At higher microwave power, thermal cavitation is induced and dominates the mass transport at the electrode surface. For the micelle-soluble redox systems tert-butylferrocene and 2,5-di-tert-butyl-1,4-benzoquinone, strong and concentration dependent current responses are observed only in the presence of microwave radiation. For the oxidation of micelle-soluble alpha-tocopherol current responses at glassy carbon electrodes are affected by adsorption and desorption processes whereas at platinum electrodes, analytical limiting currents are obtained over a wide range of alpha-tocopherol concentrations. However, for the determination of alpha-tocopherol in a commercial formulation interference from proteins is observed at platinum electrodes and direct measurements are possible only over a limited concentration range and at glassy carbon electrodes.
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Ghanem MA, Compton RG, Coles BA, Canals A, Vuorema A, John P, Marken F. Microwave activation of the electro-oxidation of glucose in alkaline media. Phys Chem Chem Phys 2005; 7:3552-9. [PMID: 16294230 DOI: 10.1039/b509784c] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The oxidation of glucose is a complex process usually requiring catalytically active electrode surfaces or enzyme-modified electrodes. In this study the effect of high intensity microwave radiation on the oxidation of glucose in alkaline solution at Au, Cu, and Ni electrodes is reported. Calibration experiments with the Fe(CN)(6)(3-/4-) redox system in aqueous 0.1 M NaOH indicate that strong thermal effects occur at both 50 and 500 microm diameter electrodes with temperatures reaching 380 K. Extreme mass transport effects with mass transport coefficients of k(mt) > 0.01 m s(-1)(or k(mt) > 1.0 cm s(-1)) are observed at 50 microm diameter electrodes in the presence of microwaves. The electrocatalytic oxidation of glucose at 500 microm diameter Au, Cu, or Ni electrodes immersed in 0.1 M NaOH and in the presence of microwave radiation is shown to be dominated by kinetic control. The magnitude of glucose oxidation currents at Cu electrodes is shown to depend on the thickness of a pre-formed oxide layer. At 50 microm diameter Au, Cu, or Ni electrodes microwave enhanced current densities are generally higher, but only at Au electrodes is a significantly increased rate for the electrocatalytic oxidation of glucose to gluconolactone observed. This rate enhancement appears to be independent of temperature but microwave intensity dependent, and therefore non-thermal in nature. Voltammetric currents observed at Ni electrodes in the presence of microwaves show the best correlation with glucose concentration and are therefore analytically most useful.
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de la Hoz A, Díaz-Ortiz A, Moreno A. Microwaves in organic synthesis. Thermal and non-thermal microwave effects. Chem Soc Rev 2005; 34:164-78. [PMID: 15672180 DOI: 10.1039/b411438h] [Citation(s) in RCA: 1041] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microwave irradiation has been successfully applied in organic chemistry. Spectacular accelerations, higher yields under milder reaction conditions and higher product purities have all been reported. Indeed, a number of authors have described success in reactions that do not occur by conventional heating and even modifications of selectivity (chemo-, regio- and stereoselectivity). The effect of microwave irradiation in organic synthesis is a combination of thermal effects, arising from the heating rate, superheating or "hot spots" and the selective absorption of radiation by polar substances. Such phenomena are not usually accessible by classical heating and the existence of non-thermal effects of highly polarizing radiation--the "specific microwave effect"--is still a controversial topic. An overview of the thermal effects and the current state of non-thermal microwave effects is presented in this critical review along with a view on how these phenomena can be effectively used in organic synthesis.
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Affiliation(s)
- Antonio de la Hoz
- Departamento de Química Orgánica, Facultad de Química, Universidad de Castilla-La Mancha, E-13071 Ciudad Real, Spain.
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Abstract
Although fire is now rarely used in synthetic chemistry, it was not until Robert Bunsen invented the burner in 1855 that the energy from this heat source could be applied to a reaction vessel in a focused manner. The Bunsen burner was later superseded by the isomantle, oil bath, or hot plate as a source for applying heat to a chemical reaction. In the past few years, heating and driving chemical reactions by microwave energy has been an increasingly popular theme in the scientific community. This nonclassical heating technique is slowly moving from a laboratory curiosity to an established technique that is heavily used in both academia and industry. The efficiency of "microwave flash heating" in dramatically reducing reaction times (from days and hours to minutes and seconds) is just one of the many advantages. This Review highlights recent applications of controlled microwave heating in modern organic synthesis, and discusses some of the underlying phenomena and issues involved.
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Affiliation(s)
- C Oliver Kappe
- Institute of Chemistry, Organic and Bioorganic Chemistry, Karl-Franzens University Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
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45
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Kappe CO. Kontrolliertes Erhitzen mit Mikrowellen in der modernen organischen Synthese. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200400655] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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46
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Microwave enhanced electrochemistry: mass transport effects and steady state voltammetry in the sub-millisecond time domain. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2004.06.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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47
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Sur UK, Marken F, Coles BA, Compton RG, Dupont J. Microwave activation in ionic liquids induces high temperature-high speed electrochemical processes. Chem Commun (Camb) 2004:2816-7. [PMID: 15599421 DOI: 10.1039/b410655e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Self-focusing of intense microwave radiation at the tip of a 25 microm diameter platinum disk microelectrode immersed into the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM(+)PF(6)(-)) containing 1 mM ferrocene causes dramatically (two orders of magnitude) enhanced voltammetric current signals and temperatures in excess of 600 K (at the electrode surface)--extreme conditions sufficient for condensed phase pyrolysis processes to occur.
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Affiliation(s)
- Ujjal Kumar Sur
- Department of Chemistry, Loughborough University, Loughborough, Leicestershire, UK LE11 3TU
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Walton DJ, Iniesta J, Plattes M, Mason TJ, Lorimer JP, Ryley S, Phull SS, Chyla A, Heptinstall J, Thiemann T, Fuji H, Mataka S, Tanaka Y. Sonoelectrochemical effects in electro-organic systems. ULTRASONICS SONOCHEMISTRY 2003; 10:209-216. [PMID: 12818384 DOI: 10.1016/s1350-4177(02)00153-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper describes recent studies in organic sonoelectrochemistry at Coventry University, including the oxidation of thiophene monoxides, degradation of dye pollutants, formation of conducting polymers and electrosynthetic modification of proteins.
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Affiliation(s)
- David J Walton
- School of Science and the Environment, Coventry University, Priory Street, Coventry CV1 5FB, UK.
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