Manipulating the self-assembling process to obtain control over the morphologies of copper oxide in hydrothermal synthesis and creating pores in the oxide architecture

Ziyi Zhong; Vivien Ng; Jizhong Luo; Siew Pheng Teh; Jaclyn Teo; Aharon Gedanken

doi:10.1021/la063344x

Manipulating the self-assembling process to obtain control over the morphologies of copper oxide in hydrothermal synthesis and creating pores in the oxide architecture

Ziyi Zhong^*, Vivien Ng, Jizhong Luo, Siew Pheng Teh, Jaclyn Teo, Aharon Gedanken

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

45 Scopus citations

Abstract

Copper oxide with various morphologies was synthesized by the hydrolysis of Cu(ac)₂ with urea under mild hydrothermal conditions. In the synthesis, a series of organic amines with one or two amine groups (monoamine and diamine), including isobutylamine, octylamine (OLA), dodecylamine, octadecylamine (monoamines), ethylenediamine dihydrochloride, and hexamethylenediamine (diamines), was used as the "structure-directing agent". The monoamines led to the formation of one-dimensional (1D) aggregates of the copper oxide precursor particles (Pre-CuO), while the diamines led to the formation of two-dimensional (2D) aggregates. In both cases, the shorter carbon-chain amine molecules showed a stronger structure-directing function than that of the longer carbon-chain amine molecules. Next, in a series of syntheses, OLA was selected for further study, and the experimental parameters were systematically manipulated. When the hydrolysis was adjusted to a very slow rate by coupling the hydrolysis reaction with an esterification reaction, ID aggregates of Pre-CuO were formed; when the hydrolysis rate was in the middle range, spherical Pre-CuO architectures composed of smaller linear aggregates were formed. However, under the high hydrolysis rates achieved by increasing the precipitation agent (urea) or by conducting the reaction at high temperatures (≥ 120 °C), only Pre-CuO nanoparticles with a featureless morphology were formed. The formed spherical Pre-CuO architectures can be converted to a porous structure (CuO_x) after removing the OLA molecules via calcination. Compared to the ID and 2D aggregates, this porous architecture is highly thermally stable and did not collapse even after calcination at 500 °C. Preliminary results showed that the porous structure can be used both as a catalyst support and as a catalyst for the oxidation of CO at low temperatures.

Original language	English
Pages (from-to)	5971-5977
Number of pages	7
Journal	Langmuir
Volume	23
Issue number	11
DOIs	https://doi.org/10.1021/la063344x
State	Published - 22 May 2007
Externally published	Yes

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@article{914879eee14f498691c928a6f2279e8d,

title = "Manipulating the self-assembling process to obtain control over the morphologies of copper oxide in hydrothermal synthesis and creating pores in the oxide architecture",

abstract = "Copper oxide with various morphologies was synthesized by the hydrolysis of Cu(ac)2 with urea under mild hydrothermal conditions. In the synthesis, a series of organic amines with one or two amine groups (monoamine and diamine), including isobutylamine, octylamine (OLA), dodecylamine, octadecylamine (monoamines), ethylenediamine dihydrochloride, and hexamethylenediamine (diamines), was used as the {"}structure-directing agent{"}. The monoamines led to the formation of one-dimensional (1D) aggregates of the copper oxide precursor particles (Pre-CuO), while the diamines led to the formation of two-dimensional (2D) aggregates. In both cases, the shorter carbon-chain amine molecules showed a stronger structure-directing function than that of the longer carbon-chain amine molecules. Next, in a series of syntheses, OLA was selected for further study, and the experimental parameters were systematically manipulated. When the hydrolysis was adjusted to a very slow rate by coupling the hydrolysis reaction with an esterification reaction, ID aggregates of Pre-CuO were formed; when the hydrolysis rate was in the middle range, spherical Pre-CuO architectures composed of smaller linear aggregates were formed. However, under the high hydrolysis rates achieved by increasing the precipitation agent (urea) or by conducting the reaction at high temperatures (≥ 120 °C), only Pre-CuO nanoparticles with a featureless morphology were formed. The formed spherical Pre-CuO architectures can be converted to a porous structure (CuOx) after removing the OLA molecules via calcination. Compared to the ID and 2D aggregates, this porous architecture is highly thermally stable and did not collapse even after calcination at 500 °C. Preliminary results showed that the porous structure can be used both as a catalyst support and as a catalyst for the oxidation of CO at low temperatures.",

author = "Ziyi Zhong and Vivien Ng and Jizhong Luo and Teh, {Siew Pheng} and Jaclyn Teo and Aharon Gedanken",

year = "2007",

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doi = "10.1021/la063344x",

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TY - JOUR

T1 - Manipulating the self-assembling process to obtain control over the morphologies of copper oxide in hydrothermal synthesis and creating pores in the oxide architecture

AU - Zhong, Ziyi

AU - Ng, Vivien

AU - Luo, Jizhong

AU - Teh, Siew Pheng

AU - Teo, Jaclyn

AU - Gedanken, Aharon

PY - 2007/5/22

Y1 - 2007/5/22

N2 - Copper oxide with various morphologies was synthesized by the hydrolysis of Cu(ac)2 with urea under mild hydrothermal conditions. In the synthesis, a series of organic amines with one or two amine groups (monoamine and diamine), including isobutylamine, octylamine (OLA), dodecylamine, octadecylamine (monoamines), ethylenediamine dihydrochloride, and hexamethylenediamine (diamines), was used as the "structure-directing agent". The monoamines led to the formation of one-dimensional (1D) aggregates of the copper oxide precursor particles (Pre-CuO), while the diamines led to the formation of two-dimensional (2D) aggregates. In both cases, the shorter carbon-chain amine molecules showed a stronger structure-directing function than that of the longer carbon-chain amine molecules. Next, in a series of syntheses, OLA was selected for further study, and the experimental parameters were systematically manipulated. When the hydrolysis was adjusted to a very slow rate by coupling the hydrolysis reaction with an esterification reaction, ID aggregates of Pre-CuO were formed; when the hydrolysis rate was in the middle range, spherical Pre-CuO architectures composed of smaller linear aggregates were formed. However, under the high hydrolysis rates achieved by increasing the precipitation agent (urea) or by conducting the reaction at high temperatures (≥ 120 °C), only Pre-CuO nanoparticles with a featureless morphology were formed. The formed spherical Pre-CuO architectures can be converted to a porous structure (CuOx) after removing the OLA molecules via calcination. Compared to the ID and 2D aggregates, this porous architecture is highly thermally stable and did not collapse even after calcination at 500 °C. Preliminary results showed that the porous structure can be used both as a catalyst support and as a catalyst for the oxidation of CO at low temperatures.

AB - Copper oxide with various morphologies was synthesized by the hydrolysis of Cu(ac)2 with urea under mild hydrothermal conditions. In the synthesis, a series of organic amines with one or two amine groups (monoamine and diamine), including isobutylamine, octylamine (OLA), dodecylamine, octadecylamine (monoamines), ethylenediamine dihydrochloride, and hexamethylenediamine (diamines), was used as the "structure-directing agent". The monoamines led to the formation of one-dimensional (1D) aggregates of the copper oxide precursor particles (Pre-CuO), while the diamines led to the formation of two-dimensional (2D) aggregates. In both cases, the shorter carbon-chain amine molecules showed a stronger structure-directing function than that of the longer carbon-chain amine molecules. Next, in a series of syntheses, OLA was selected for further study, and the experimental parameters were systematically manipulated. When the hydrolysis was adjusted to a very slow rate by coupling the hydrolysis reaction with an esterification reaction, ID aggregates of Pre-CuO were formed; when the hydrolysis rate was in the middle range, spherical Pre-CuO architectures composed of smaller linear aggregates were formed. However, under the high hydrolysis rates achieved by increasing the precipitation agent (urea) or by conducting the reaction at high temperatures (≥ 120 °C), only Pre-CuO nanoparticles with a featureless morphology were formed. The formed spherical Pre-CuO architectures can be converted to a porous structure (CuOx) after removing the OLA molecules via calcination. Compared to the ID and 2D aggregates, this porous architecture is highly thermally stable and did not collapse even after calcination at 500 °C. Preliminary results showed that the porous structure can be used both as a catalyst support and as a catalyst for the oxidation of CO at low temperatures.

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U2 - 10.1021/la063344x

DO - 10.1021/la063344x

M3 - 文章

C2 - 17469856

AN - SCOPUS:34249902285

SN - 0743-7463

VL - 23

SP - 5971

EP - 5977

JO - Langmuir

JF - Langmuir

IS - 11

ER -

Manipulating the self-assembling process to obtain control over the morphologies of copper oxide in hydrothermal synthesis and creating pores in the oxide architecture

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