Preparation of CuNb2O6 nanocrystalline powders by sol–gel method

Zhang, Ying Chun; Fu, Baojian; Liu, Qiang

doi:10.1016/j.jallcom.2008.10.108

Cited by 11 publications

(3 citation statements)

References 13 publications

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“…These results suggest that the optimal pH value is around 7 for preparing the MgTa 2 O 6 powders in this sol-gel process. This is also consistent with that of our previous work in synthesizing MgNb 2 O 6 powders by this method [12,13]. These phenomena can be explained by the effects of pH values on the stability of sol-gel.…”

Section: Resultssupporting

confidence: 92%

Synthesis of MgTa2O6 nano-powders by citrate sol–gel method

Zhang

Liu

et al. 2010

Journal of Alloys and Compounds

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a b s t r a c tA sol-gel processing was used to synthesize MgTa 2 O 6 nano-powders at a low temperature using Ta 2 O 5 as starting materials. The decomposition of precursors, and the crystal structure and microstructure of the MgTa 2 O 6 powders were characterized by DTA/TG, XRD and SEM techniques. The effects of the amount of citrate acid and pH values on the stability of sol-gel solution and microstructure of MgTa 2 O 6 nano-powders were investigated. XRD and TG/DTA results show that the MgTa 2 O 6 nano-powders can be synthesized at 900 • C, and non-stoichiometric ratio of Mg to Ta was required to form the single MgTa 2 O 6 phase. The average particle sizes of MgTa 2 O 6 powders range from 25 nm to 100 nm with different CA/Ta and pH values.

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Section: Resultssupporting

confidence: 92%

Synthesis of MgTa2O6 nano-powders by citrate sol–gel method

Zhang

Liu

et al. 2010

Journal of Alloys and Compounds

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“…One class of metal niobates conform to the formula MNb 2 O 6 , where M 2+ = a + 2 cation (Zn, Cu, Co, Ni, Mn, etc.) with <1.0 Å ionic radius and an orthorhombic columbite structure. , To date, solid-state reactions at high temperatures have predominantly been the method of choice for synthesizing transition metal niobates as they are easily made from the corresponding metal oxide precursors. ,, However, the last two decades have witnessed a trend toward utilizing lower temperatures and a variety of solution-based techniques such as sol–gel synthesis, coprecipitation, or hydrothermal synthesis. − However, these approaches, along with their solid-state synthesis counterparts, suffer from a similar drawback: long reaction times (usually several hours) that prohibit the quick screening of large numbers of possible material candidates in combinatorial schemes. Furthermore, solid-state synthesis suffers from the need for high external energy input to maintain the elevated temperature during the synthesis.…”

Section: Introductionmentioning

confidence: 99%

Solution Combustion Synthesis, Characterization, and Photoelectrochemistry of CuNb₂O₆ and ZnNb₂O₆ Nanoparticles

et al. 2016

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This study reports on the solution combustion synthesis of two different ternary niobium oxides, namely, p-CuNb 2 O 6 and n-ZnNb 2 O 6. Such ternary oxides are attractive candidates in the "Holy Grail" search for efficient and stable semiconductors for solar energy conversion and environmental remediation. We demonstrate how this time-and energy-efficient method is capable of synthesizing high surface area and crystalline nanoparticles of the above compounds with enhanced optoelectronic properties. The synthesized crystalline samples were characterized by powder X-ray diffraction (with Rietveld refinement for phase purity), diffuse reflectance UV−visible and Raman spectroscopy, electron microscopy, and photoelectrochemical (PEC) techniques. The band structure of these oxides was probed by linear sweep voltammetry and by measuring their photoaction spectra (internal photon to electron conversion efficiency vs wavelength). The obtained bandgap energy values (1.9 and 3.2 eV for the Cu-and Zn-containing compounds, respectively) were in reasonable agreement with those obtained via electronic structure calculations (2.07 and 3.53 eV). Finally, p-CuNb 2 O 6 showed promising activity for the PEC reduction of CO 2 , while n-ZnNb 2 O 6 was active for sulfite and water photooxidation. HCOOH, CH 3 OH, etc., produced by the photochemical or PEC conversion of CO 2. 4,8,9 The most extensively studied n-type metal oxide semiconductor is TiO 2 , mostly because of its robustness, outstanding stability in aqueous media, coupled with nontoxicity and earth abundance of its constituent elements. 10,11 However, the wide bandgap (3.0−3.2 eV) of this material limits its application in solar energy utilization processes. A plethora of other n-type oxide semiconductors (binary or even ternary oxides) have been applied as photoanodes (e.g., ZnO, WO 3 , Nb 2 O 5 , SrTiO 3). 12 On the other hand, p-type semiconductors Special Issue: Kohei Uosaki Festschrift

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“…This precipitate contains fluoride ions, so it is necessary to wash for the removal of fluoride. This is done with dilute ammonia and then distilled water, as for niobium hydroxide [13,14]. The tantalum hydroxide is separated by filtration, then washed repeatedly with hot dilute ammonia and then hot water.…”

Section: Introductionmentioning

confidence: 99%