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Burg A, Yadav KK, Meyerstein D, Kornweitz H, Shamir D, Albo Y. Effect of Sol-Gel Silica Matrices on the Chemical Properties of Adsorbed/Entrapped Compounds. Gels 2024; 10:441. [PMID: 39057464 PMCID: PMC11276444 DOI: 10.3390/gels10070441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 06/27/2024] [Accepted: 06/30/2024] [Indexed: 07/28/2024] Open
Abstract
The sol-gel process enables the preparation of silica-based matrices with tailored composition and properties that can be used in a variety of applications, including catalysis, controlled release, sensors, separation, etc. Commonly, it is assumed that silica matrices prepared via the sol-gel synthesis route are "inert" and, therefore, do not affect the properties of the substrate or the catalyst. This short review points out that porous silica affects the properties of adsorbed/entrapped species and, in some cases, takes an active part in the reactions. The charged matrix affects the diffusion of ions, thus affecting catalytic and adsorption processes. Furthermore, recent results point out that ≡Si-O. radicals are long-lived and participate in redox processes. Thus, clearly, porous silica is not an inert matrix as commonly considered.
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Affiliation(s)
- Ariela Burg
- Chemical Engineering Department, Sami Shamoon College of Engineering, Beer-Sheva 84100, Israel; (A.B.); (K.K.Y.)
| | - Krishna K. Yadav
- Chemical Engineering Department, Sami Shamoon College of Engineering, Beer-Sheva 84100, Israel; (A.B.); (K.K.Y.)
| | - Dan Meyerstein
- Chemical Sciences Department and The Radical Research Center, Ariel University, Ariel 40700, Israel;
- Chemistry Department, Ben-Gurion University, Beer-Sheva 8410501, Israel
| | - Haya Kornweitz
- Chemical Sciences Department and The Radical Research Center, Ariel University, Ariel 40700, Israel;
| | - Dror Shamir
- Nuclear Research Centre Negev, Beer-Sheva 9001, Israel
| | - Yael Albo
- Chemical Engineering Department and The Radical Research Center, Ariel University, Ariel 40700, Israel
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Aharon S, Patra SG, Meyerstein D, Tzur E, Shamir D, Albo Y, Burg A. Heterogeneous Electrocatalytic Oxygen Evolution Reaction by a Sol-Gel Electrode with Entrapped Na 3 [Ru 2 (μ-CO 3 ) 4 ]: The Effect of NaHCO 3. Chemphyschem 2023; 24:e202300517. [PMID: 37655884 DOI: 10.1002/cphc.202300517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023]
Abstract
The Na3 [Ru2 (μ-CO3 )4 ] complex is acting as a water oxidation catalyst in a homogeneous system. Due to the significance of heterogeneous systems and the effect of bicarbonate on the kinetic, we studied the bicarbonate effect on the heterogeneous electrocatalyst by entrapping the Na3 [Ru2 (μ-CO3 )4 ] complex in a sol-gel matrix. We have developed two types of sol-gel electrodes, which differ by the precursor, and are demonstrating their stability over a minimum of 200 electrochemical cycles. The pH increases affected the currents and kcat for both types of electrodes, and their hydrophobicity, which was obtained from the precursor type, influenced the electrocatalytic process rate. The results indicate that NaHCO3 has an important role in the catalytic activity of the presented heterogeneous systems; without NaHCO3 , the diffusing species is probably OH- , which undergoes diffusion via the Grotthuss mechanism. To the best of our knowledge, this is the first study to present a simple and fast one-step entrapment process for the Na3 [Ru2 (μ-CO3 )4 ] complex by the sol-gel method under standard laboratory conditions. The results contribute to optimizing the WSP, ultimately helping expand the usage of hydrogen as a green and more readily available energy source.
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Affiliation(s)
- Shiran Aharon
- Chemical Sciences Department, Ariel University, Ariel, 40700, Israel
- Chemical Engineering Department, Sami Shamoon College of Engineering, Beer-Sheva, 8410802, Israel
| | - Shanti Gopal Patra
- Chemical Sciences Department, Ariel University, Ariel, 40700, Israel
- Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302, India
| | - Dan Meyerstein
- Chemical Sciences Department, Ariel University, Ariel, 40700, Israel
- Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Eyal Tzur
- Chemical Engineering Department, Sami Shamoon College of Engineering, Ashdod, 77245, Israel
| | - Dror Shamir
- Nuclear Research Centre Negev, Beer-Sheva, 84190, Israel
| | - Yael Albo
- Chemical Engineering Department, Ariel University, Ariel, 40700, Israel
| | - Ariela Burg
- Chemical Engineering Department, Sami Shamoon College of Engineering, Beer-Sheva, 8410802, Israel
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Kottapurath Vijay A, Sharma VK, Meyerstein D. Overlooked Formation of Carbonate Radical Anions in the Oxidation of Iron(II) by Oxygen in the Presence of Bicarbonate. Angew Chem Int Ed Engl 2023; 62:e202309472. [PMID: 37439593 DOI: 10.1002/anie.202309472] [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: 07/04/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 07/14/2023]
Abstract
Iron(II), (Fe(H2 O)6 2+ , (FeII ) participates in many reactions of natural and biological importance. It is critically important to understand the rates and the mechanism of FeII oxidation by dissolved molecular oxygen, O2 , under environmental conditions containing bicarbonate (HCO3 - ), which exists up to millimolar concentrations. In the absence and presence of HCO3 - , the formation of reactive oxygen species (O2 ⋅- , H2 O2 , and HO⋅) in FeII oxidation by O2 has been suggested. In contrast, our study demonstrates for the first time the rapid generation of carbonate radical anions (CO3 ⋅- ) in the oxidation of FeII by O2 in the presence of bicarbonate, HCO3 - . The rate of the formation of CO3 ⋅- may be expressed as d[CO3 ⋅- ]/dt=[FeII [[O2 ][HCO3 - ]2 . The formation of reactive species was investigated using 1 H nuclear magnetic resonance (1 H NMR) and gas chromatographic techniques. The study presented herein provides new insights into the reaction mechanism of FeII oxidation by O2 in the presence of bicarbonate and highlights the importance of considering the formation of CO3 ⋅- in the geochemical cycling of iron and carbon.
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Affiliation(s)
- Aswin Kottapurath Vijay
- Department of Chemical Sciences and The Radical Research Center, Ariel University, Ariel, 40700, Israel
- Chemistry Department, Ben-Gurion University, Beer-Sheva, 8410501, Israel
| | - Virender K Sharma
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA
| | - Dan Meyerstein
- Department of Chemical Sciences and The Radical Research Center, Ariel University, Ariel, 40700, Israel
- Chemistry Department, Ben-Gurion University, Beer-Sheva, 8410501, Israel
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High Oxygen-Yield Homogeneous Sonophotocatalysis for Water-splitting Using Theraphthal. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Bio-Inspired Molecular Catalysts for Water Oxidation. Catalysts 2021. [DOI: 10.3390/catal11091068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The catalytic tetranuclear manganese-calcium-oxo cluster in the photosynthetic reaction center, photosystem II, provides an excellent blueprint for light-driven water oxidation in nature. The water oxidation reaction has attracted intense interest due to its potential as a renewable, clean, and environmentally benign source of energy production. Inspired by the oxygen-evolving complex of photosystem II, a large of number of highly innovative synthetic bio-inspired molecular catalysts are being developed that incorporate relatively cheap and abundant metals such as Mn, Fe, Co, Ni, and Cu, as well as Ru and Ir, in their design. In this review, we briefly discuss the historic milestones that have been achieved in the development of transition metal catalysts and focus on a detailed description of recent progress in the field.
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