Mechanism for Hydrothermal-carbothermal Synthesis of AlN Nanopowders  

水热-碳热合成AlN纳米粉体的机理

作　　者：FENG Guanzheng YANG Jian ZHOU Du CHEN Qiming XU Wentao ZHOU Youfu 冯关正;杨健;周渡;陈啟明;许文涛;周有福(中国科学院福建物质结构研究所,光电材料化学与物理重点实验室,福州350002;福建光电信息科技创新实验室,福州350108;中国科学院大学,北京100039)

机构地区：[1]Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China [2]Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China,Fuzhou 350108,China [3]University of Chinese Academy of Sciences,Beijing 100039,China

出　　处：《无机材料学报》2025年第1期104-110,I0009-I0011,共10页Journal of Inorganic Materials

基　　金：National Key Research and Development Program of China(2022YFB3708500,2023YFB3611000);Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2020ZZ109)。

摘　　要：Currently,the carbothermal reduction-nitridation(CRN)process is the predominant method for preparing aluminum nitride(AlN)powder.Although AlN powder prepared by CRN process exhibits high purity and excellent sintering activity,it also presents challenges such as the necessity for high reaction temperatures and difficulties in achieving uniform mixing of its raw materials.This study presents a comprehensive investigation into preparation process of AlN nanopowders using a combination of hydrothermal synthesis and CRN.In the hydrothermal reaction,a homogeneous composite precursor consisting of carbon and boehmite(γ-AlOOH)is synthesized at 200℃using aluminum nitrate as the aluminum source,sucrose as the carbon source,and urea as the precipitant.During the hydrothermal process,the precursor develops a core-shell structure,with boehmite tightly coated with carbon(γ-AlOOH@C)due to electrostatic attraction.Compared with conventional precursor,the hydrothermal hybrid offers many advantages,such as ultrafine particles,uniform particle size distribution,good dispersion,high reactivity,and environmental friendliness.The carbon shell enhances thermodynamic stability of γ-Al_(2)O_(3) compared to the corundum phase(α-Al_(2)O_(3))by preventing the loss of the surface area in alumina.This stability enables γ-Al_(2)O_(3) to maintain high reactivity during CRN process,which initiates at 1300℃,and concludes at 1400℃.The underlying mechanisms are substantiated through experiments and thermodynamic calculations.This research provides a robust theoretical and experimental foundation for the hydrothermal combined carbothermal preparation of non-oxide ceramic nanopowders.碳热还原氮化法是应用最广泛的制备AlN粉体的方法。该工艺制备的AlN粉体纯度高且烧结活性优良,但是存在反应温度高、原料难以混合均匀等不足。本研究将水热合成与碳热还原氮化法相结合制备AlN纳米粉体。以硝酸铝为铝源、蔗糖为碳源、尿素为沉淀剂,在200℃水热合成碳和勃姆石(γ-AlOOH)均质复合前驱体。前驱体通过静电吸引形成碳紧密包覆勃姆石的核壳结构(γ-AlOOH@C)。与传统前驱体相比,水热复合物具有超细颗粒、粒度分布均匀、分散性好、反应活性高、环境友好等优点。在氧化铝相的稳定性方面,碳壳通过抑制氧化铝的表面积损失,使γ-Al_(2)O_(3)相比刚玉相(α-Al_(2)O_(3)相)的热稳定性更好,γ-Al_(2)O_(3)在碳热还原过程中能保持较高的反应活性,该反应始于1300℃,止于1400℃(比传统碳热还原法低200℃)。本研究通过实验和热力学计算验证了相关机理,为水热法结合碳热法制备非氧化物纳米陶瓷粉体提供了有效的理论和实验依据。

关 键 词：aluminum nitride carbothermal reduction-nitridation MECHANISM hydrothermal synthesis PRECURSOR 

分 类 号：TM282[一般工业技术—材料科学与工程]