Enhanced up-conversion luminescence from NaYF4:Yb,Er nanocrystals by Gd3+ ions induced phase transformation and plasmonic Au nanosphere arrays

We report a gradient-temperature hydrothermal method to construct hierarchical Zn2SnO4 hollow boxes, and the obtained results are based on phase transformation between metastable ZnSnO3 and stable Zn2SnO4.

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From Ni-based nanoprecursors to NiO nanostructures: morphology-controlled synthesis and structure-dependent electrochemical behavior

New Journal of Chemistry ◽

10.1039/c4nj01398k ◽

2015 ◽

Vol 39 (1) ◽

pp. 676-682 ◽

Cited By ~ 25

Author(s):

Gang Cheng ◽

Yinan Yan ◽

Rong Chen

Keyword(s):

Phase Transformation ◽

Hydrothermal Method ◽

Electrochemical Behavior ◽

Controlled Synthesis

Phase transformation and morphology tailoring of NiO nanostructures employed for supercapacitor electrodes have been achieved using the Ni-based nanostructure precursors synthesized via a facile urea-controlled hydrothermal method.

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Effects of Temperature and Mineralizer on In2O3 Crystals Synthesized by Hydrothermal Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.287 ◽

2014 ◽

Vol 884-885 ◽

pp. 287-291

Author(s):

Wen Li Zheng ◽

Wei Yang

Keyword(s):

Phase Transformation ◽

Hydrothermal Method ◽

Crystalline Phase ◽

Fill Factor ◽

Pure Water ◽

Transformation Rule ◽

Secondary Crystallization ◽

Different Temperatures ◽

Effects Of Temperature

In ( OH )3, InOOH and In2O3crystals were synthesized by hydrothermal method, using pure water, 1mol/L KOH and 5mol/L KOH as mineralizer, the fill factor of 35%, reacted at the temperature of 200°C, 250°C and 350°C respectively, and time of 24 h. The phase transformation rule of In ( OH )3, InOOH and In2O3was studied in different temperatures and mineralizer, and their morphology have been analyzed. When pure water was used, temperature was 200°C , the results showed that In ( OH )3crystalline phase was no obvious transformation and secondary crystallization, the crystal had nonspecific morphology. While temperature was 250°C and 350°C, the In ( OH )3crystal transformed into InOOH. When 1 mol/L KOH and 5 mol/L KOH was used, temperature was 200°C , the In ( OH )3crystal had secondary crystallization. In particular, the largest-scale crystal was about 20 μm, the smallest crystal was less than 200 nm when 5 mol/L KOH was used. InOOH crystal and a small amount of In2O3were obtained in 250°C. When temperature reached 350°C , the In2O3with cubic bixbyite structure was obtained, exposing the faces { 001}, { 010}, { 100} and { 101}, and the length of crystal side was more than 50 μm.

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Synthesis of θ-Al2O3 Whiskers with Twins

Metals ◽

10.3390/met11060895 ◽

2021 ◽

Vol 11 (6) ◽

pp. 895

Author(s):

Nan Liao ◽

Xiaojia Su ◽

Haiwen Zhang ◽

Qingguo Feng ◽

Salvatore Grasso ◽

...

Keyword(s):

Phase Transformation ◽

Specific Surface ◽

Hydrothermal Method ◽

Surface Area ◽

Tetragonal Phase ◽

Monoclinic Phase ◽

Argon Atmosphere ◽

Molar Ratio ◽

Average Width ◽

The Mean

In this work, θ-Al2O3 whiskers with twins were successfully fabricated by a hydrothermal method followed by annealing at 1000 °C in argon atmosphere using Al2(SO4)3·18H2O, CO(NH2)2 and PEG2000 as initial materials. It is confirmed that precursor of AlO(OH) whiskers is suitable to be used for preparing alumina whiskers when the molar ratio of Al3+: CO(NH2)2 is selected to be 1:6. The mean length of obtained whiskers is 1.5 μm and the average width is 0.1 μm. Interestingly, it is found that the as-prepared θ-Al2O3 whiskers consist of twins with (100) plane as the twin surface, which is ascribed to the phase transformation from tetragonal phase (δ-Al2O3) to monoclinic phase (θ-Al2O3) during the annealing. Additionally, the specific surface area of θ-Al2O3 whiskers is measured to be 38.2 m2/g.

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Phase transformation and spectroscopic adjustment of Gd2O3:Eu3+ synthesized by hydrothermal method

Journal of Luminescence ◽

10.1016/j.jlumin.2013.11.040 ◽

2014 ◽

Vol 152 ◽

pp. 172-175 ◽

Cited By ~ 16

Author(s):

Zijun Wang ◽

Pei Wang ◽

Jiuping Zhong ◽

Hongbin Liang ◽

Jing Wang

Keyword(s):

Phase Transformation ◽

Hydrothermal Method

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Effect of Growth Time on the Structural and Morphological Properties of MoS2 Synthesized via Hydrothermal Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1028.162 ◽

2021 ◽

Vol 1028 ◽

pp. 162-167

Author(s):

Tengku Emrinaldi ◽

Cuk Imawan ◽

Riski Titian Ginting ◽

Vivi Fauzia

Keyword(s):

Phase Transformation ◽

Hydrothermal Method ◽

Molybdenum Disulfide ◽

Structural Properties ◽

Hydrothermal Process ◽

Sodium Molybdate ◽

Diffraction Peak ◽

Morphological Properties ◽

Growth Time ◽

Simple Hydrothermal Process

Recently, molybdenum disulfide (MoS2), have been explored as photothermal materials for solar evaporation. However, the optimum phase for photothermal material, 1T-MoS2 or 2H-MoS2, is still debatable. In this work, we observed the morphological and structural properties of MoS2 prepared by a simple hydrothermal process at 200 °C in three different growth times (16, 20, and 24 hours) using Na2MoO4·2H2O (sodium molybdate) as a Mo precursor, and CS(NH2)2 (thiourea) as S precursor. MoS2 nanoflowers were successfully prepared with nanosheets petals and its diameter increased from 0.4 to 2.8 and 4.5 as the growth time increased from 16 to 20 and 24 hours. The increase in growth time also led to improve the Mo:S ratio from 1:8 to 1:5 and facilitate the phase transformation from 1T to 2H as indicated by the shifting of (002) diffraction peak from 9.25° to higher degrees (12.98°, and 14.12°).

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