First unseeded hydrothermal synthesis of microporous vanadosilicate AM-6

Ismail, Mariam N.; Fraiman, Naftali D.; Callahan, Dennis M.; Gürsoy, Gamze; Viveiros, Edward; Özkanat, Önnaz; Ji, Zhaoxia; Willey, Ronald J.; Warzywoda, Juliusz; Sacco, Albert

doi:10.1016/j.micromeso.2008.12.020

Cited by 22 publications

(18 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the second step of AM-6 film preparation, the seeded ITO coated glass substrates were then placed in the reaction vessels of AM-6 growth solutions [10,16,17]. For this purpose, the seeded substrates facing downwards were placed diagonally in the 10 mL [10,16,17].…”

Section: Film Preparationmentioning

confidence: 99%

“…Among them, vanadosilicate AM-6, isostructural with ETS-10, is a 3-D, 12-membered microporous zeo-type material, consisting of SiO 4 tetrahedra and VO 6 octahedra [9]. Unlike ETS-10, AM-6 has 1-D VO 3 2-quantum wires instead of TiO 3 2-with narrower band gap compared to titanosilicate ETS-10 (i.e., *3.8 vs. *4.3 eV, for AM-6 and ETS-10, respectively) [10][11][12]. These quantum wires have the potential to be used as building blocks in nanoscale electronic devices [13].…”

Section: Introductionmentioning

confidence: 99%

“…These quantum wires have the potential to be used as building blocks in nanoscale electronic devices [13]. AM-6, which is also photocatalytically active under visible light, has unique catalytic properties due to; (1) redox-active transition metal center, (2) accessibility of multiple oxidation states, (3) effectiveness in oxidation chemistry [10,14,15]. Furthermore, AM-6 has novel magnetic and electric properties attributed to the valence state of vanadium in VO 3 2-quantum wire which could be easily manipulated by altering the oxidation state of vanadium [14].…”

Section: Introductionmentioning

confidence: 99%

“…Then, Sacco, Jr. et al reported the first time synthesis of seedless vanadosilicate AM-6 crystals by using structure directing agent (SDA) with molar composition of 4.5Na 2 Yoon et al [17] synthesized seedless and template free AM-6 crystals for the first time in comparison with ETS-10 core/AM-6 shell crystals made by Rocha et al [16] and ETS-10-free AM-6 crystals containing tetramethylammonium ion (TMA ? ) as structure directing agent synthesized by Sacco, Jr. et al [10]. AM-6 samples in powder form synthesized by Yoon et al, Sacco, Jr. et al, and Rocha et al were denoted as AM-6-(Y), AM-6-(S) and AM-6-RA respectively.…”

Section: Introductionmentioning

confidence: 99%

“…To the best of our knowledge, only one paper was reported on the synthesis of vanadosilicate AM-6 membranes, where a-alumina substrates were used as support [22]. In the current study, the ETS-10 core/AM-6 shell methodology was applied in the original formation of AM-6 crystals in powder form by using ETS-10 as seeds [10,16,17]. In that way, it was aimed to investigate the formation of AM-6 thin films on ITO coated glass substrates using ETS-10 as seeds for the first time, focusing on the quality of the quantum wires and the orientation of the crystallites in those films.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Secondary growth of microporous vanadosilicate AM-6 films

2016

View full text Add to dashboard Cite

Oriented vanadosilicate AM-6 thin films with an average thickness of 1-2 lm were prepared on the ITO coated glass substrates using secondary growth method with a partial a(b)-out-of-plane preferred crystal orientation for the first time. In secondary growth method, titanosilicate ETS-10 crystals were deposited on the substrate from a colloidal suspension to form seed layers. Then, the hydrothermal growth of the seed crystals was conducted to form AM-6 films. It was observed that the AM-6 films formed possess similar 1-D VO 3 2-quantum wires as also observed in powder AM-6 crystals. Afterward, the effect of reaction temperature and amount of water in the secondary growth gel on crystal morphology and a(b)-out-of-plane crystallographic preferred orientation (CPO) were investigated to gain a better understanding of the secondary growth mechanism of vanadosilicate AM-6 films. The results suggested that the increased amount of water leads to increased CPO in the AM-6 films, whereas an increase in reaction temperature from 503 to 528 K leads to more c-oriented AM-6 films with a decreased CPO value. Furthermore, an increase in the reaction temperature led to a decrease in the reaction time, resulting in the formation of quartz impurity. Accordingly, well intergrown a(b)-out-of-plane oriented vanadosilicate films were grown for the first time using ETS-10 seed crystals and it is believed that this work provides an effective pathway for controlling the synthesis of AM-6 films expanding the possible range of applications of these materials possessing 1-D quantum wires.

show abstract

Section: Film Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Secondary growth of microporous vanadosilicate AM-6 films

2016

View full text Add to dashboard Cite

show abstract

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires

Datta¹,

Yoon²

2010

Angewandte Chemie

View full text Add to dashboard Cite

The synthesis and characterization of one-dimensional (1D) semiconductor quantum-confined materials are important, since they have great potential as building blocks for nanoscale electronic devices and other applications. [1][2][3][4][5][6][7][8][9] Among the known 1D semiconductor materials, molecular wires or quantum wires [1][2][3][4][5] are the thinnest 1D quantum-confined materials. However, examples of such quantum wires are rare. Recently, we elucidated the interesting quantum-confinement properties of titanate (TiO 3 2À ) quantum wire [10] regularly placed within a titanosilicate molecular sieve known as ETS-10. [11][12][13] It shows a length-dependent quantum-confinement effect even at length scales longer than 50 nm. [10] Its estimated effective reduced exciton mass along the wire m z is lower than 0.0006 m e (m e = rest mass of electron), which is much lower than the lowest reported values (InSb: 0.014 m e , single-walled carbon nanotubes (SWNT): 0.019 m e ) and indicate much higher exciton mobility along the quantum wire than in InSb and SWNTs. The nature of the electronic absorption of the titanate quantum wire was reportedly oxide-to-Ti IV charge transfer or ligand-to-metal charge transfer (LMCT). [14][15][16] The stretching frequency of the titanate wire increases with increasing electron density of the wire. [14] After elucidation of such important properties of titanate quantum wire, it would be of interest to determine the physicochemical properties of the closely related vanadate (VO 3 2À ) quantum wire. In this regard, the discovery of vanadosilicate AM-6 by Rocha, Anderson, and co-workers in 1997 [17] [designated AM-6-(RA)] is important, since it adopts the ETS-10 structure but with VO 3 2À quantum wires replacing TiO 3 2À quantum wires. Unfortunately, however, ETS-10 crystals were required as seeds to induce ETS-10 structure in the vanadosilicate. Accordingly, AM-6-(RA) inevitably contains ETS-10 crystals within AM-6. Thus, AM-6-(RA) should more strictly be defined as ETS-10 core/AM-6 shell. Furthermore, Lobo, Doren, and co-workers revealed that VO 3 2À quantum wires in AM-6-(RA) are composed of both V 4+ and V 5+ . [18][19][20] As a result, it is intrinsically impossible to elucidate the physicochemical properties of the pure V IV O 3 2À quantum wire. Furthermore, their procedure always simultaneously produces substantial amounts of quartz. Hence, methods to prepare ETS-10-free, pure AM-6 have long been awaited.Twelve years after the report of AM-6-(RA), Sacco, Jr. and co-workers finally developed a method of synthesizing ETS-10-free AM-6. [21] However, they had to use tetramethylammonium ion (TMA + ) as structure-directing agent. Accordingly, this AM-6 contains TMA + ions within the channels. We designate this AM-6 as AM-6-(S)-TMA. We found that AM-6-(S)-TMA also contains both V 4+ and V 5+ (see below). Furthermore, the TMA + ions are tightly encapsulated within and hence completely block the silica channels. As a result, ion exchange of the pristine cations (Na + and K + ) with other cat...

show abstract

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires

Datta

Yoon

2010

Angew Chem Int Ed

View full text Add to dashboard Cite

The synthesis and characterization of one-dimensional (1D) semiconductor quantum-confined materials are important, since they have great potential as building blocks for nanoscale electronic devices and other applications. [1][2][3][4][5][6][7][8][9] Among the known 1D semiconductor materials, molecular wires or quantum wires [1][2][3][4][5] are the thinnest 1D quantum-confined materials. However, examples of such quantum wires are rare. Recently, we elucidated the interesting quantum-confinement properties of titanate (TiO 3 2À ) quantum wire [10] regularly placed within a titanosilicate molecular sieve known as ETS-10. [11][12][13] It shows a length-dependent quantum-confinement effect even at length scales longer than 50 nm.[10] Its estimated effective reduced exciton mass along the wire m z is lower than 0.0006 m e (m e = rest mass of electron), which is much lower than the lowest reported values (InSb: 0.014 m e , single-walled carbon nanotubes (SWNT): 0.019 m e ) and indicate much higher exciton mobility along the quantum wire than in InSb and SWNTs. The nature of the electronic absorption of the titanate quantum wire was reportedly oxide-to-Ti IV charge transfer or ligand-to-metal charge transfer (LMCT). [14][15][16] The stretching frequency of the titanate wire increases with increasing electron density of the wire. [14] After elucidation of such important properties of titanate quantum wire, it would be of interest to determine the physicochemical properties of the closely related vanadate (VO 3 2À ) quantum wire. In this regard, the discovery of vanadosilicate AM-6 by Rocha, Anderson, and co-workers in 1997 [17] [designated AM-6-(RA)] is important, since it adopts the ETS-10 structure but with VO 3 2À quantum wires replacing TiO 3 2À quantum wires. Unfortunately, however, ETS-10 crystals were required as seeds to induce ETS-10 structure in the vanadosilicate. Accordingly, AM-6-(RA) inevitably contains ETS-10 crystals within AM-6. Thus, AM-6-(RA) should more strictly be defined as ETS-10 core/AM-6 shell. Furthermore, Lobo, Doren, and co-workers revealed that VO 3 2À quantum wires in AM-6-(RA) are composed of both V 4+ and V 5+. [18][19][20] As a result, it is intrinsically impossible to elucidate the physicochemical properties of the pure V IV O 3 2À quantum wire. Furthermore, their procedure always simultaneously produces substantial amounts of quartz. Hence, methods to prepare ETS-10-free, pure AM-6 have long been awaited.Twelve years after the report of AM-6-(RA), Sacco, Jr. and co-workers finally developed a method of synthesizing ETS-10-free AM-6.[21] However, they had to use tetramethylammonium ion (TMA + ) as structure-directing agent. Accordingly, this AM-6 contains TMA + ions within the channels. We designate this AM-6 as AM-6-(S)-TMA. We found that AM-6-(S)-TMA also contains both V 4+ and V 5+ (see below). Furthermore, the TMA + ions are tightly encapsulated within and hence completely block the silica channels. As a result, ion exchange of the pristine cations (Na + and K + ) with other cation...

show abstract

First unseeded hydrothermal synthesis of microporous vanadosilicate AM-6

Cited by 22 publications

References 42 publications

Secondary growth of microporous vanadosilicate AM-6 films

Secondary growth of microporous vanadosilicate AM-6 films

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires

Contact Info

Product

Resources

About

First unseeded hydrothermal synthesis of microporous vanadosilicate AM-6

Cited by 22 publications

References 42 publications

Secondary growth of microporous vanadosilicate AM-6 films

Secondary growth of microporous vanadosilicate AM-6 films

Synthesis of Ideal AM‐6 and Elucidation of V4+‐to‐O Charge Transfer in Vanadate Quantum Wires

Synthesis of Ideal AM‐6 and Elucidation of V4+‐to‐O Charge Transfer in Vanadate Quantum Wires

Contact Info

Product

Resources

About

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires

Synthesis of Ideal AM‐6 and Elucidation of V⁴⁺‐to‐O Charge Transfer in Vanadate Quantum Wires