硅酸盐学报

水热合成SrTi_xZr_（1-_x_）O₃的微观形貌及第一性原理计算

PDF下载

李啸虎 ¹ , 张笑妍 ¹ , 王楚瑜 ²^,³ , 李卓然 ¹ , 郭晶晶 ¹ , 干科 ²

硅酸盐学报 | 研究论文 2024,52(6): 2003-2015

收起

硅酸盐学报 |研究论文 2024 , 52 (6) : 2003 -2015

水热合成SrTi_xZr_（1-_x_）O₃的微观形貌及第一性原理计算

全屏

李啸虎¹, 张笑妍¹, 王楚瑜²^,³, 李卓然¹, 郭晶晶¹, 干科²

作者信息

^1．北京科技大学新材料技术研究院，北京 100083

^2．中国科学院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所，北京 100190

^3．中国科学院大学化学工程学院，北京 100049

通讯作者:

张笑妍（1990—），女，副教授。

干科（1988—），男，副教授。

作者简介:

李啸虎（1998—），男，硕士研究生。

Micro-Morphology and First-Principle Calculation of Hydrothermally Synthesized SrTi_xZr₍₁_-_x₎O₃

Xiaohu LI¹, Xiaoyan ZHANG¹, Chuyu WANG²^,³, Zhuoran LI¹, Jingjing GUO¹, Ke GAN²

Affiliations

^1.Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China

^2.CAS Key Laboratory of Green Process and Engineering, National Engineering Research Center of green recycling for strategic metal resources, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

^3.School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China

Corresponding Author:

ZHANG Xiaoyan (1990-), female, Ph.D., Associate Professor. E-mail: zhangxiaoyan@ustb.edu.cn;

GAN Ke (1988-), male, Ph.D., Associate Professor. jdzganke@163.com

LI Xiaohu (1998-), male, Master candidate. E-mail: 1530211281@qq.com

出版时间: 2024-06-20 doi: 10.14062/j.issn.0454-5648.20230705

文章导航

摘要

收起

采用水热合成钙钛矿SrTi_xZr_（1-_x_）O₃纳米单晶颗粒，系统研究不同钛/锆比（Ti/Zr，摩尔比）对晶体颗粒物相组成、微观形貌和光响应特征的影响规律。当Ti∶Zr摩尔比为1∶3和3∶1时，颗粒均为六面体形貌；但在Ti/Zr摩尔比为1时，部分颗粒呈星状形貌。采用第一性原理计算，获得不同超晶胞构型的能带结构和晶格参数，从理论上阐明了钛/锆比对颗粒形貌变化规律的影响机制，不同晶体构型诱导的异相成核机制，以及原子随机排列产生的晶格畸变，共同导致星状颗粒形貌的形成。随着Ti的摩尔比降低，禁带宽度逐渐增大，这与实验结果相符。

关键词

锆钛酸锶 / 水热法 / 颗粒形貌 / 第一性原理

Abstract

收起

Introduction

Strontium zirconate titanate is an important dielectric material with a high dielectric constant and a low dielectric loss. Also, as a semiconductor catalytic material, it has an application potential in the fields of photocracking water and photodegradation of organic matter. However, as a semiconductor catalytic material, SrTi_xZr_(1-_x₎O₃ has a wide band gap and a low carrier migration rate. Element substitution is commonly performed via ion doping at the B site (i.e., Ti element site) in the lattice. The resulting lattice defects inhibit photogenerated electron-hole recombination and narrow the band gap, thereby improving the catalytic efficiency. At present, the doping of transition metal elements such as Nb, Co, Rh, Fe and Ce is beneficial to reducing the band gap and promoting its response to visible light. Little studies have been reported to explain the morphology of single crystal particles by theoretical calculations. In this paper, SrTi_xZr_(1-_x₎O₃ single crystal nanoparticles with different Ti/Zr molar ratios were synthesized by a hydrothermal method. The micro-morphology, crystal size and light response characteristics of SrTi_xZr_(1-_x₎O₃ single crystal nanoparticles were investigated. In addition, the micro-morphology of SrTi_xZr_(1-_x₎O₃ single crystal nanoparticles was also revealed based on the first-principles calculation.

Methods

Strontium chloride hexahydrate (SrCl₂·6H₂O) and titanium tetrachloride (TiCl₄) from Sinopharm Chemical Reagent Co., Ltd., China, were used as raw materials, respectively. Zirconium tetrachloride (ZrCl₄) and lithium hydroxide (LiOH) from Shanghai McLean Biochemical Technology Co., Ltd., China, were used as zirconium source and pH regulator. SrTi_xZr_(1-_x₎O₃ nano-single crystal particles with different molar ratios of titanium to zirconium were prepared by a hydrothermal method at 180 ℃ for 12 h.

The phase composition, microstructure and element distribution of the samples were determined by X-ray diffractometer and thermal field emission scanning electron microscope with energy dispersive spectrometer. The light response characteristics of the samples were characterized by UV-visible spectrophotometer. Based on the first-principles density functional theory (DFT), 3 kinds of SrTi_0.25Zr_0.75O₃, 6 kinds of SrTi_0.5Zr_0.5O₃ and 3 kinds of SrTi_0.75Zr_0.25O₃ 2×2×2 supercell configurations were designed and calculated.

Results and discussion

SrTi_xZr_(1-_x₎O₃ nano-single crystal exhibits a perovskite structure. The diffraction peak becomes wider when element Zr gradually replaces elemen Ti. SrCO₃ as an impurity phase can be removed by calcining at 1 200 ℃. The hydrothermal reaction synthesized SrTiO₃ with a cubic phase shows a regular hexahedron morphology. Most of SrZrO₃ crystals with an orthorhombic phase are flat octahedron morphology. The particles basically tend to be regular hexahedron morphology when Ti∶Zr=1∶3 and 3∶1. However, the lattice distortion effect of SrTi_xZr_(1-_x₎O₃ crystal reaches the maximum, and some of the morphologies are star-shaped when Ti∶Zr=1∶1.

The lattice parameters of SrTi_xZr_(1-_x₎O₃ unit cell configuration were calculated by first-principles density functional theory. In SrTi_0.5Zr_0.5O₃ system, the configurations (iv), (viii) and (ix) are transformed into orthorhombic crystals, and the maximum lattice constant c reaches 9.5 Å. The ground state energies of configurations (iii), (v) and (xii) are 2.538, 1.530 eV and 0.949 eV, respectively. Based on the principle of energy minimization, the crystal grows preferentially according to these configurations. Thus, SrTi_xZr_(1-_x₎O₃ (x=0.25, 0.75) grains exhibit a uniform hexahedral morphology. The octahedral dip angle, bond lengths and angles of four configurations (iii), (v), (ix) and (vii) are selected to analyze the symmetry change and lattice distortion of the crystals. The octahedral bond angles are more than 179.9° in the three lowest ground state energy configurations, which maintain a structural symmetry. However, Ti(Zr)O₆ octahedron tilt angles of the configuration (ix) are mainly concentrated at 145°-153°. The Ti(Zr)—O bond lengths are distributed in the range of 1.711-2.926 Å. This indicates that equimolar Ti/Zr causes the lattice distortion due to the change of bond length and angle. The lattice distortion promotes the formation of star-like morphology. The light response characteristics show that the band gap of SrTi_xZr_(1-_x₎O₃ nano-single crystal particles decreases with the increase of Ti⁴⁺ proportion. The band gaps of SrTi_0.25Zr_0.75O₃, SrTi_0.5Zr_0.5O₃ and SrTi_0.75Zr_0.25O₃ are 3.70, 3.47 eV and 3.34 eV, respectively, which are consistent with those obtained via the first-principles calculations.

Conclusions

Perovskite structure SrTi_xZr_(1-_x₎O₃ nano-single crystal particles with different Ti/Zr molar ratios were synthesized by a hydrothermal method. SrTi_0.25Zr_0.75O₃ and SrTi_0.75Zr_0.25O₃ both were transformed into a hexahedral morphology. A special star-shaped polyhedron morphology appeared in SrTi_0.5Zr_0.5O₃ sample. The lattice parameters and energy band structure of SrTi_xZr_(1-_x₎O₃ were obtained via the first-principles calculations. The lattice distortion effect appeared as Ti/Zr=1. There were lattice parameters of three configurations in the supercell lattice arrangement are a=b≠c, where c can be up to 9.570 Å. The actual crystal growth process of the SrTi_0.5Zr_0.5O₃ system was partially carried out according to these arrangements. The heterogeneous nucleation mechanism was induced by different crystal configurations and the lattice distortion, which promoted the formation of star-shaped grains. The band gap change rule of the samples was verified by ultraviolet-visible spectrophotometer. The increase of element Ti ratio led to the decrease of the band gap since the energy level of Ti 3d orbital was lower than that of Zr 4d orbital.

Key words

strontium zirconate titanate / hydrothermal method / particle morphology / first-principles

引用本文

李啸虎, 张笑妍, 王楚瑜, 李卓然, 郭晶晶, 干科. 水热合成SrTi_xZr_（1-_x_）O₃的微观形貌及第一性原理计算. 硅酸盐学报, 2024 , 52 (6) : 2003 -2015 . DOI: 10.14062/j.issn.0454-5648.20230705

Xiaohu LI, Xiaoyan ZHANG, Chuyu WANG, Zhuoran LI, Jingjing GUO, Ke GAN. Micro-Morphology and First-Principle Calculation of Hydrothermally Synthesized SrTi_xZr₍₁_-_x₎O₃[J]. Journal of the Chinese Ceramic Society, 2024 , 52 (6) : 2003 -2015 . DOI: 10.14062/j.issn.0454-5648.20230705

基金

收起

国家自然科学基金项目(52202074; 52102058)
北京市自然科学基金项目(2214081)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2024年第52卷第6期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20230705

接收时间：2023-09-10
首发时间：2026-10-22
出版时间：2024-06-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2023-09-10
修回日期：2023-10-21

基金

国家自然科学基金项目(52202074; 52102058)

北京市自然科学基金项目(2214081)

作者信息

^1．北京科技大学新材料技术研究院，北京 100083

^2．中国科学院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所，北京 100190

^3．中国科学院大学化学工程学院，北京 100049

通讯作者:

张笑妍（1990—），女，副教授。

干科（1988—），男，副教授。

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20230705

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT