Kinetic analysis of zinc oxide anisotropic growth in supercritical water

Orita, Yasuhiko; Akizuki, Makoto; Oshima, Yoshito

doi:10.1016/j.supflu.2019.104609

Cited by 10 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The typical crystal growth mechanism of iron oxide under hydrothermal environment is suggested to be the Ostwald ripening phenomenon, where smaller particles dissolve and recrystallize on the larger particles’ surface. , In Ostwald ripening, the high solubility of metal oxide generally accelerates the dissolution and recrystallization process. , Additionally, Fujii et al suggest that the introduction of monocarboxylic acid increases the solubility of the metal oxide via the formation of a metal organic complex, leading to the acceleration of the dissolution and recrystallization process . Based on these reports for the Ostwald ripening under a hydrothermal environment, a lower solubility of the longer-chain monocarboxylic acid should lead to the lower solubility of Fe 3 O 4 NPs, resulting in a smaller growth rate compared to the shorter-chain cases.…”

Section: Resultsmentioning

confidence: 99%

Systematically Designed Surface and Morphology of Magnetite Nanoparticles Using Monocarboxylic Acid with Various Chain Lengths under Hydrothermal Condition

2023

Self Cite

View full text Add to dashboard Cite

Hydrothermal synthesis of surface-modified magnetite nanoparticles (NPs) was performed in a batch reactor at 200 °C for 20 min while using monocarboxylic acid with various alkyl chain lengths (C6 to C18) as surface modifiers. The short-chain cases (C6 to C12) successfully gave the surfacemodified NPs with uniform shape and magnetite structure, while the long-chain cases (C14 to C18) gave the NPs with nonuniform shape and two structures (magnetite and hematite). Additionally, the synthesized NPs were revealed to have single crystallinity, high stability, and ferromagnetic property, which were useful for hyperthermia therapy via various characterization techniques. These investigations would guide the selection guidelines for a surface modifier to control the structure, surface, and magnetic properties of surface-modified magnetite NPs with high crystallinity and stability, particularly for hyperthermia therapy applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Systematically Designed Surface and Morphology of Magnetite Nanoparticles Using Monocarboxylic Acid with Various Chain Lengths under Hydrothermal Condition

2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, Orita et al. [ 74 ] proposed that Zn 2+ is first bound with varying amounts of OH − to form a variety of intermediate products, including Zn(OH) + , Zn(OH) 2 , Zn(OH) 3 − , and Zn(OH) 4 2− . However, Li et al.…”

Section: Resultsmentioning

confidence: 99%

“…There are many controversies about the pattern of the growth unit for ZnO crystal. For example, Orita et al [74] proposed that Zn 2+ is first bound with varying amounts of OH − to form a variety of intermediate products, including Zn(OH) + , Zn(OH) 2 , Zn(OH) 3 − , and Zn(OH) 4 2− . However, Li et al [75] put forward that [Zn(OH) 4 ] 2− bonded together via a dehydration reaction to form Zn x O y (OH) z (z+2y−2x)− in high supersaturated solutions, and then the Zn x O y (OH) z (z+2y−2x)− precipitated when it reached the critical size of ZnO particles.…”

Section: Growth Mechanism Of Zno Crystal With Different Morphologiesmentioning

confidence: 99%

Synthesis of ZnO Crystal with Micro‐Nano Structures by a Continuous Co‐Precipitation Method: Morphological Evolution and Mechanism Analysis

Zhong

Huang

Wang

et al. 2023

Cryst. Res. Technol.

View full text Add to dashboard Cite

ZnO crystals are employed in numerous industries, but precisely controlling their morphologies is still challenging. In this work, a continuous flow process for synthesizing ZnO crystals is developed based on the co‐precipitation method. ZnO crystals at different morphologies, including needle‐like, rod‐like, flower‐like, spindle‐like, and nanospheres, are successfully prepared at low temperature. The influence of reaction temperature, pH value, ZnCl2 feeding concentration, and reaction time on the morphology, size, and purity of ZnO crystals is systematically investigated. The results of X‐ray diffraction show that the high‐purity ZnO can only be produced when the reaction temperature is above 75 °C. The band gap energies of ZnO evaluated by UV–vis diffuse reflectance spectroscopy increase with the synthesis temperature. According to scanning electron microscope (SEM) findings, the size of ZnO crystals is regulated by controlling the reaction time. Interestingly, the morphology of ZnO crystals is changed from 1D to 3D structure by controlling the feeding concentration of ZnCl2. Moreover, a concentration difference mechanism of ZnO crystal morphology evolution is proposed by monitoring the real‐time concentration of free Zn2+ ions.

show abstract

Supercritical hydrothermal synthesis of nano-zinc oxide: Process and mechanism

Liu

Wang

et al. 2022

Ceramics International

View full text Add to dashboard Cite

Kinetic analysis of zinc oxide anisotropic growth in supercritical water

Cited by 10 publications

References 26 publications

Systematically Designed Surface and Morphology of Magnetite Nanoparticles Using Monocarboxylic Acid with Various Chain Lengths under Hydrothermal Condition

Systematically Designed Surface and Morphology of Magnetite Nanoparticles Using Monocarboxylic Acid with Various Chain Lengths under Hydrothermal Condition

Synthesis of ZnO Crystal with Micro‐Nano Structures by a Continuous Co‐Precipitation Method: Morphological Evolution and Mechanism Analysis

Supercritical hydrothermal synthesis of nano-zinc oxide: Process and mechanism

Contact Info

Product

Resources

About