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Nguyen CC, Dinh CT, Do TO. Hollow Sr/Rh-codoped TiO2 photocatalyst for efficient sunlight-driven organic compound degradation. RSC Adv 2017. [DOI: 10.1039/c6ra25987a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sunlight-driven photocatalysis has emerged as a potential technology to address organic pollutant issues.
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Saberi Safaei T, Mepham A, Zheng X, Pang Y, Dinh CT, Liu M, Sinton D, Kelley SO, Sargent EH. High-Density Nanosharp Microstructures Enable Efficient CO 2 Electroreduction. NANO LETTERS 2016; 16:7224-7228. [PMID: 27736080 DOI: 10.1021/acs.nanolett.6b03615] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Conversion of CO2 to CO powered by renewable electricity not only reduces CO2 pollution but also is a means to store renewable energy via chemical production of fuels from CO. However, the kinetics of this reaction are slow due its large energetic barrier. We have recently reported CO2 reduction that is considerably enhanced via local electric field concentration at the tips of sharp gold nanostructures. The high local electric field enhances CO2 concentration at the catalytic active sites, lowering the activation barrier. Here we engineer the nucleation and growth of next-generation Au nanostructures. The electroplating overpotential was manipulated to generate an appreciably increased density of honed nanoneedles. Using this approach, we report the first application of sequential electrodeposition to increase the density of sharp tips in CO2 electroreduction. Selective regions of the primary nanoneedles are passivated using a thiol SAM (self-assembled monolayer), and then growth is concentrated atop the uncovered high-energy planes, providing new nucleation sites that ultimately lead to an increase in the density of the nanosharp structures. The two-step process leads to a new record in CO2 to CO reduction, with a geometric current density of 38 mA/cm2 at -0.4 V (vs reversible hydrogen electrode), and a 15-fold improvement over the best prior reports of electrochemical surface area (ECSA) normalized current density.
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Klinkova A, De Luna P, Dinh CT, Voznyy O, Larin EM, Kumacheva E, Sargent EH. Rational Design of Efficient Palladium Catalysts for Electroreduction of Carbon Dioxide to Formate. ACS Catal 2016. [DOI: 10.1021/acscatal.6b01719] [Citation(s) in RCA: 227] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zheng XL, Dinh CT, de Arquer FPG, Zhang B, Liu M, Voznyy O, Li YY, Knight G, Hoogland S, Lu ZH, Du XW, Sargent EH. ZnFe2 O4 Leaves Grown on TiO2 Trees Enhance Photoelectrochemical Water Splitting. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:3181-3188. [PMID: 27145726 DOI: 10.1002/smll.201600534] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/20/2016] [Indexed: 06/05/2023]
Abstract
TiO2 has excellent electrochemical properties but limited solar photocatalytic performance in light of its large bandgap. One important class of visible-wavelength sensitizers of TiO2 is based on ZnFe2 O4 , which has shown fully a doubling in performance relative to pure TiO2 . Prior efforts on this important front have relied on presynthesized nanoparticles of ZnFe2 O4 adsorbed on a TiO2 support; however, these have not yet achieved the full potential of this system since they do not provide a consistently maximized area of the charge-separating heterointerface per volume of sensitizing absorber. A novel atomic layer deposition (ALD)-enhanced synthesis of sensitizing ZnFe2 O4 leaves grown on the trunks of TiO2 trees is reported. These new materials exhibit fully a threefold enhancement in photoelectrochemical performance in water splitting compared to pristine TiO2 under visible illumination. The new materials synthesis strategy relies first on the selective growth of FeOOH nanosheets, 2D structures that shoot off from the sides of the TiO2 trees; these templates are then converted to ZnFe2 O4 with the aid of a novel ALD step, a strategy that preserves morphology while adding the Zn cation to achieve enhanced optical absorption and optimize the heterointerface band alignment.
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Burdyny T, Riordon J, Dinh CT, Sargent EH, Sinton D. Self-assembled nanoparticle-stabilized photocatalytic reactors. NANOSCALE 2016; 8:2107-2115. [PMID: 26700375 DOI: 10.1039/c5nr05859g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The efficiency of nanostructured photocatalysts continues to improve at an impressive pace and is closing in on those needed for commercial applications; however, present-day reactor strategies used to deploy these nanostructures fail to achieve the sufficient areas (>1 m(2)) needed for solar application. Here we report the Self-assembled Nanoparticle-stabilized Photocatalytic Reactor (SNPR), a fully-scalable reactor strategy comprised only of nanoparticles adsorbed at the fluid-fluid interfaces of oil-in-water emulsions, water-in-oil emulsions, and CO2-in-water foams. We show that SNPRs naturally disperse over open water and need no physical substrate, requiring only photocatalysts and fluid. In environmental applications the SNPR provides more than double the reaction rate of a comparable single-phase reactor. In continuous mode, the SNPR achieves 100% photocatalyst retention and processes 96% of the stream over 20 hours; in contrast, the performance of a comparable aqueous suspension declines to zero over this interval, losing all photocatalyst to the outlet stream. We further characterize the photoactivity of individual photocatalytic droplets, with reactants in both the continuous and dispersed phases. These results demonstrate SNPRs as a robust and flexible reactor strategy and a route-to-scale for nanomaterials.
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Dinh CT, Hoogland S, Sargent EH. Spontaneous and Light-Driven Conversion of NOx on Oxide-Modified TiO2 Surfaces. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b03710] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Reza Gholipour M, Dinh CT, Béland F, Do TO. Nanocomposite heterojunctions as sunlight-driven photocatalysts for hydrogen production from water splitting. NANOSCALE 2015; 7:8187-208. [PMID: 25804291 DOI: 10.1039/c4nr07224c] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hydrogen production via photocatalytic water splitting using sunlight has enormous potential in solving the worldwide energy and environmental crisis. The key challenge in this process is to develop efficient photocatalysts which must satisfy several criteria such as high chemical and photochemical stability, effective charge separation and strong sunlight absorption. The combination of different semiconductors to create composite materials offers a promising way to achieve efficient photocatalysts because doing so can improve the charge separation, light absorption and stability of the photocatalysts. In this review article, we summarized the most recent studies on semiconductor composites for hydrogen production under visible light irradiation. After a general introduction about the photocatalysis phenomenon, typical heterojunctions of widely studied heterogeneous semiconductors, including titanium dioxide, cadmium sulfide and graphitic carbon nitride are discussed in detail.
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Nguyen TD, Dinh CT, Do TO. Tailoring the assembly, interfaces, and porosity of nanostructures toward enhanced catalytic activity. Chem Commun (Camb) 2015; 51:624-35. [DOI: 10.1039/c4cc05741d] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The evolution of nanotechnology has inspired materials scientists to invent nanostructures with achievements in numerous practical applications, particularly in catalysis.
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Dinh CT, Yen H, Kleitz F, Do TO. Frontispiz: Three-Dimensional Ordered Assembly of Thin-Shell Au/TiO 2Hollow Nanospheres for Enhanced Visible-Light-Driven Photocatalysis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201482671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Dinh CT, Yen H, Kleitz F, Do TO. Frontispiece: Three-Dimensional Ordered Assembly of Thin-Shell Au/TiO 2Hollow Nanospheres for Enhanced Visible-Light-Driven Photocatalysis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/anie.201482671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Dinh CT, Pham MH, Seo Y, Kleitz F, Do TO. Design of multicomponent photocatalysts for hydrogen production under visible light using water-soluble titanate nanodisks. NANOSCALE 2014; 6:4819-4829. [PMID: 24664235 DOI: 10.1039/c3nr06602a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report the design of efficient multicomponent photocatalysts (MPs) for H2 production under visible light by using water-soluble ultrathin titanate nanodisks (TNDs) stabilized by tetraethylammonium cations (TEA(+)) as building blocks. The photocatalysts are designed in such a way to significantly enhance simultaneously the efficiency of the three main steps in the photocatalytic process i.e., light absorption, charge separation and catalytic reaction. We show, as an example, the construction of water-soluble CdS-TND-Ni MPs. The designed CdS-TND-Ni MPs, in which CdS nanoparticles and TNDs are intimately assembled to enhance the charge transfer and surface area, are controlled in composition to optimize visible light absorption. The conception of the MPs allows them to be highly dispersed in water which markedly improves the photocatalytic H2 production process. Most importantly, a Ni co-catalyst is selectively located on the surface of TNDs, enabling vectorial electron transfer from CdS to TND and to Ni, which drastically improves the charge separation. Consequently, under visible light illumination (λ ≥ 420 nm), the optimally designed CdS-TND-Ni MPs could generate H2 from ethanol-water solution with rate as high as 15.326 mmol g(-1) h(-1) during a reaction course of 15 h and with an apparent quantum yield of 24% at 420 nm. Moreover, we also demonstrate that TNDs can be combined with other single or mixed metal sulfide to form water-soluble metal sulfide-TNDs composites which could also be of great interest for photocatalytic H2 production.
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Dinh CT, Yen H, Kleitz F, Do TO. Three-Dimensional Ordered Assembly of Thin-Shell Au/TiO2Hollow Nanospheres for Enhanced Visible-Light-Driven Photocatalysis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400966] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Dinh CT, Yen H, Kleitz F, Do TO. Three-Dimensional Ordered Assembly of Thin-Shell Au/TiO2Hollow Nanospheres for Enhanced Visible-Light-Driven Photocatalysis. Angew Chem Int Ed Engl 2014; 53:6618-23. [DOI: 10.1002/anie.201400966] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Indexed: 11/10/2022]
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Pham MH, Dinh CT, Vuong GT, Ta ND, Do TO. Visible light induced hydrogen generation using a hollow photocatalyst with two cocatalysts separated on two surface sides. Phys Chem Chem Phys 2014; 16:5937-41. [DOI: 10.1039/c3cp54629b] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Eshraghi AA, Dinh CT, Bohorquez J, Angeli S, Abi-Hachem R, Van De Water TR. Local drug delivery to conserve hearing: mechanisms of action of eluted dexamethasone within the cochlea. Cochlear Implants Int 2013; 12 Suppl 1:S51-3. [DOI: 10.1179/146701011x13001035753254] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Nguyen TD, Dinh CT, Mrabet D, Tran-Thi MN, Do TO. Controlled synthesis of ceria nanoparticles for the design of nanohybrids. J Colloid Interface Sci 2013; 394:100-7. [DOI: 10.1016/j.jcis.2012.12.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 11/21/2012] [Accepted: 12/09/2012] [Indexed: 11/16/2022]
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Dinh CT, Seo Y, Nguyen TD, Kleitz F, Do TO. Rücktitelbild: Controlled Synthesis of Titanate Nanodisks as Versatile Building Blocks for the Design of Hybrid Nanostructures (Angew. Chem. 27/2012). Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dinh CT, Seo Y, Nguyen TD, Kleitz F, Do TO. Back Cover: Controlled Synthesis of Titanate Nanodisks as Versatile Building Blocks for the Design of Hybrid Nanostructures (Angew. Chem. Int. Ed. 27/2012). Angew Chem Int Ed Engl 2012. [DOI: 10.1002/anie.201204357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Dinh CT, Seo Y, Nguyen TD, Kleitz F, Do TO. Controlled Synthesis of Titanate Nanodisks as Versatile Building Blocks for the Design of Hybrid Nanostructures. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201202046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dinh CT, Seo Y, Nguyen TD, Kleitz F, Do TO. Controlled Synthesis of Titanate Nanodisks as Versatile Building Blocks for the Design of Hybrid Nanostructures. Angew Chem Int Ed Engl 2012; 51:6608-12. [DOI: 10.1002/anie.201202046] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Indexed: 11/07/2022]
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Dinh CT, Nguyen TD, Kleitz F, Do TO. A new route to size and population control of silver clusters on colloidal TiO₂ nanocrystals. ACS APPLIED MATERIALS & INTERFACES 2011; 3:2228-2234. [PMID: 21675750 DOI: 10.1021/am200480b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Formation of hybrid Ag-TiO(2) nanocrystals (NCs) in which Ag clusters are uniformly deposited on individual TiO(2) NC surface has been achieved by using hydrophobic surfactant-capped TiO(2) NCs in combination with a photodeposition technique. The population of Ag clusters on the individual TiO(2) NC surface can be controlled by the degree of hydrophobicity (e.g., the number of vacant sites) on the TiO(2) NC surface while their size may be altered simply by varying irradiation time. A reversible change in color of the resulting hybrid Ag-TiO(2) NCs is induced by alternating UV light and visible-light illumination; however, the size and population of Ag clusters on TiO(2) NCs are almost unchanged. Furthermore, these materials also exhibit much higher photocatalytic performance as compared to that of Ag supported on commercial TiO(2)-P25.
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Dinh CT, Nguyen TD, Kleitz F, Do TO. Large-scale synthesis of uniform silver orthophosphate colloidal nanocrystals exhibiting high visible light photocatalytic activity. Chem Commun (Camb) 2011; 47:7797-9. [PMID: 21633747 DOI: 10.1039/c1cc12014j] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Silver orthophosphate nanocrystals with controlled particle size have been synthesized using a simple, reproducible and easily scaled up route based on the reaction between silver ions, oleylamine and phosphoric acid. The obtained nanocrystals are highly uniform in size and exhibit high visible light activity for the photodecomposition of organic compounds.
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Dinh CT, Nguyen TD, Kleitz F, Do TO. A solvothermal single-step route towards shape-controlled titanium dioxide nanocrystals. CAN J CHEM ENG 2011. [DOI: 10.1002/cjce.20574] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Dinh CT, Bas E, Chan SS, Dinh JN, Vu L, Van De Water TR. Dexamethasone treatment of tumor necrosis factor-alpha challenged organ of Corti explants activates nuclear factor kappa B signaling that induces changes in gene expression that favor hair cell survival. Neuroscience 2011; 188:157-67. [PMID: 21571041 DOI: 10.1016/j.neuroscience.2011.04.061] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 04/27/2011] [Accepted: 04/29/2011] [Indexed: 12/20/2022]
Abstract
The objective was to determine the role of nuclear factor kappa B (NFκB) in dexamethasone base (DXMb) protection of auditory hair cells from tumor necrosis factor-alpha (TNFα)-induced loss on gene expression and cell signaling levels. Organ of Corti (OC) explants from 3-day-old rats were cultured under one of the following conditions: (1) media only--no treatment; (2) media+TNFα; (3) media+TNFα+DXMb; (4) media+TNFα+DXMb+NFκB-Inhibitor (NFκB-I); or (5) media+TNFα+DXMb+NFκBI-Scrambled control (NFκBI-C). A total of 60 organ of Corti explants (OC) were stained with FITC-Phalloidin after 96 h in culture (conditions 1-5) for hair cell counts and imaging of surface characteristics. A total of 108 OC were used for gene expression studies (i.e. B-actin, Bax, Bcl-2, Bcl-xl, and TNFR1) after 0, 24, or 48 h in vitro (conditions 1-4). A total of 86 OC were cultured (conditions 1-3) for 48 h, 36 of which were used for phosphorylated NFκB (p-NFκB) ELISA studies and 50 for whole mount anti-p-NFκB immunostain experiments. TNFα+DXMb exposed cultures demonstrated significant upregulation in anti-apoptotic Bcl-2 and Bcl-xl genes and downregulation in pro-apoptotic Bax gene expression; DXMb treatment of TNFα explants also lowered the Bax/Bcl-2 ratio and inhibited TNFR1 upregulation. After inhibiting NFκB activity with NFκB-I, the gene expression profile following TNFα+DXMb treatment now mimics that of TNFα-challenged OC explants. The levels of p-NFκB and the degree of nuclear translocation are significantly greater in TNFα+DXMb exposed OC explants than observed in the TNFα and control groups in the middle+basal turns of OC explants. These findings were supported by the results of the hair cell counts and the imaging results obtained from the whole mount OC specimens. DXMb protects against TNFα-induced apoptosis of auditory hair cells in vitro via activation of NFκB signaling in hair cell nuclei, and regulation of the expression levels of anti- and pro-apoptotic genes and a pro-inflammatory gene.
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Nguyen TD, Dinh CT, Do TO. A general procedure to synthesize highly crystalline metal oxide and mixed oxide nanocrystals in aqueous medium and photocatalytic activity of metal/oxide nanohybrids. NANOSCALE 2011; 3:1861-1873. [PMID: 21409273 DOI: 10.1039/c1nr10109a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A conventional and general route has been exploited to the high yield synthesis of many kinds of highly crystalline metal oxide and mixed oxide nanocrystals with different morphologies including belt, rod, truncated-octahedron, cubic, sphere, sheet via the hydrothermal reaction of inorganic precursors in aqueous solution in the presence of bifunctional 6-aminohexanoic acid (AHA) molecules as a capping agent. This method is a simple, reproducible and general route for the preparation of a variety of high-crystalline inorganic nanocrystals in scale-up. The shape of inorganic nanocrystals such as CoWO(4), La(2)(MoO(4))(3) can be controlled by simply adjusting the synthesis conditions including pH solution and reaction temperature. Further, by tuning precursor monomer concentration, the mesocrystal hierarchical aggregated microspheres (e.g., MnWO(4), La(2)(MoO(4))(3)) can be achieved, due to the spontaneous assembly of individual AHA-capped nanoparticles. These obtained AHA-capped nanocrystals are excellent supports for the synthesis of a variety of hybrid metal/oxide nanocrystals in which noble metal particles are uniformly deposited on the surface of each individual nanosupport. The photocatalytic activity of Ag/TiO(2) nanobelts as a typical hybrid photocatalyst sample for Methylene Blue degradation was also studied.
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