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Green Synthesis of Hydrocalumite (CaAl-OH-LDH) from Ca(OH)2 and Al(OH)3 and the Parameters That Influence Its Formation and Speciation. CRYSTALS 2020. [DOI: 10.3390/cryst10080672] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydrocalumite is a layered double hydroxide (LDH) that is finding increased application in numerous scientific fields. Typically, this material is produced through environmentally polluting methods such as co-precipitation, sol-gel synthesis and urea-hydrolysis. Here, the hydrothermal green (environmentally friendly) synthesis of hydrocalumite (CaAl-OH) from Ca(OH)2 and Al(OH)3 in water and the parameters that influence its formation are discussed. The parameters investigated include the reaction temperature, reaction time, molar calcium-to-aluminium ratio, the morphology/crystallinity of reactants used, mixing and the water-to-solids ratio. Hydrocalumite formation was favoured in all experiments, making up between approximately 50% and 85% of the final crystalline phases obtained. Factors that were found to encourage higher hydrocalumite purity include a low water-to-solids ratio, an increase in the reaction time, sufficient mixing, the use of amorphous Al(OH)3 with a high surface area, reaction at an adequate temperature and, most surprisingly, the use of a calcium-to-aluminium ratio that stoichiometrically favours katoite formation. X-ray diffraction (XRD) and Rietveld refinement were used to determine the composition and crystal structures of the materials formed. Scanning electron microscopy (SEM) was used to determine morphological differences and Fourier-transform infrared analysis with attenuated total reflectance (FTIR-ATR) was used to identify possible carbonate contamination, inter alia. While the synthesis was conducted in an inert environment, some carbonate contamination could not be avoided. A thorough discussion on the topic of carbonate contamination in the hydrothermal synthesis of hydrocalumite was given, and the route to improved conversion as well as the possible reaction pathway were discussed.
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Das S, Das K, Kübel C, Roy S. Light Driven Water Oxidation Coupled With C-N Coupling Reaction Using a Hybrid Cu-PW12
O40
Based Soft-Oxometalate. ChemistrySelect 2019. [DOI: 10.1002/slct.201803949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Santu Das
- EFAML; College of Chemistry; Central China Normal University; 152 Luoyu Road, Wuhan, Hubei 430079 P. R. China
- EFAML; Department of Chemical Sciences; Indian Institute of Science Education and Research, Kolkata; Mohanpur 741246 India
| | - Kousik Das
- EFAML; College of Chemistry; Central China Normal University; 152 Luoyu Road, Wuhan, Hubei 430079 P. R. China
- EFAML; Department of Chemical Sciences; Indian Institute of Science Education and Research, Kolkata; Mohanpur 741246 India
| | - Christian Kübel
- Institute of Nanotechnology INT) and Karlsruhe Nano Micro Facility (KNMF); Karlsruhe Institute of Technology (KIT); Karlsruhe Germany
| | - Soumyajit Roy
- EFAML; College of Chemistry; Central China Normal University; 152 Luoyu Road, Wuhan, Hubei 430079 P. R. China
- EFAML; Department of Chemical Sciences; Indian Institute of Science Education and Research, Kolkata; Mohanpur 741246 India
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Das S, Balaraju T, Barman S, Sreejith SS, Pochamoni R, Roy S. A Molecular CO 2 Reduction Catalyst Based on Giant Polyoxometalate {Mo 368}. Front Chem 2018; 6:514. [PMID: 30450356 PMCID: PMC6224680 DOI: 10.3389/fchem.2018.00514] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 10/05/2018] [Indexed: 11/21/2022] Open
Abstract
Photocatalytic CO2 reduction in water is one of the most attractive research pursuits of our time. In this article we report a giant polyoxometalate {Mo368} based homogeneous catalytic system, which efficiently reduces CO2 to formic acid with a maximum turnover number (TON) of 27,666, turnover frequency (TOF) of 4,611 h-1 and external quantum efficiency of the reaction is 0.6%. The catalytic system oxidizes water and releases electrons, and these electrons are further utilized for the reduction of CO2 to formic acid. A maximum of 8.3 mmol of formic acid was observed with the loading of 0.3 μmol of the catalyst. Our catalyst material is also stable throughout the reaction. The starting materials for this experiment are CO2 and H2O and the end products are HCOOH and O2. The formic acid formed in this reaction is an important H2 gas carrier and thus significant in renewable energy research.
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Affiliation(s)
- Santu Das
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
| | - Tuniki Balaraju
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
| | - Soumitra Barman
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
| | - S. S. Sreejith
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
| | - Ramudu Pochamoni
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
| | - Soumyajit Roy
- Eco-Friendly Applied Materials Laboratory, College of Chemistry, Central China Normal University, Wuhan, China
- Eco-Friendly Applied Materials Laboratory, Department of Chemical Sciences, Materials Science Centre, Mohanpur, Indian Institute of Science Education & Research, Kolkata, India
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Biswas S, Pochamoni R, Roy S. Visible-Light-Driven Carbon Dioxide Reduction Coupled with Water Oxidation by a Composite Soft-Oxometalate (SOM) System. ChemistrySelect 2018. [DOI: 10.1002/slct.201703093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Subharanjan Biswas
- EFAML; College of Chemistry; Central China Normal University; 152, Luoyu Road, Wuhan, Hubei 430079, P. R. China
- EFAML; Materials Science Centre; Department of Chemical Sciences; Indian Institute of Science Education and Research- Kolkata; Mohanpur-741246, Nadia West Bengal
| | - Ramudu Pochamoni
- EFAML; College of Chemistry; Central China Normal University; 152, Luoyu Road, Wuhan, Hubei 430079, P. R. China
- EFAML; Materials Science Centre; Department of Chemical Sciences; Indian Institute of Science Education and Research- Kolkata; Mohanpur-741246, Nadia West Bengal
| | - Soumyajit Roy
- EFAML; College of Chemistry; Central China Normal University; 152, Luoyu Road, Wuhan, Hubei 430079, P. R. China
- EFAML; Materials Science Centre; Department of Chemical Sciences; Indian Institute of Science Education and Research- Kolkata; Mohanpur-741246, Nadia West Bengal
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Barman S, Das S, S S S, Garai S, Pochamoni R, Roy S. Selective light driven reduction of CO 2 to HCOOH in water using a {MoV 9} n (n = 1332-3600) based soft-oxometalate (SOM). Chem Commun (Camb) 2018; 54:2369-2372. [PMID: 29450415 DOI: 10.1039/c7cc09520a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A soft-oxometalate (SOM) based on Mo and V i.e. {MoV9} in their highest oxidation state reduces CO2 to HCOOH selectively in water. Catalysis initiates without the use of any photosensitizer and solvent water acts as the sacrificial electron donor which gets oxidized to generate oxygen. Electrons and protons released in this process reduce CO2 to HCOOH.
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Affiliation(s)
- Soumitra Barman
- EFAML, College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, 430079 Hubei, P. R. China.
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Crans DC, Peters BJ, Wu X, McLauchlan CC. Does anion-cation organization in Na+-containing X-ray crystal structures relate to solution interactions in inhomogeneous nanoscale environments: Sodium-decavanadate in solid state materials, minerals, and microemulsions. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.03.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Das S, Misra A, Roy S. Light driven decarboxylative cross coupling of acrylic acid and iodobenzene using [Mo 132 ] type keplerate as a catalyst. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.06.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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