石英型氧化锗的低温溶剂热制备及其结构演变机制
Preparation and Morphological Evolution of β-Quartz-Type Germanium Dioxide Nanocrystals
王欣雨 1胡学萍 1吴文静 1邹旭 2赵世华2
作者信息
- 1. 海南师范大学物理与电子工程学院
- 2. 海南省院士创新平台;海南师范大学物理与电子工程学院
- 折叠
摘要
本文以商业α-GeO2粉末为前驱体，在180℃条件下采用溶剂热法制备GeO2纳米晶，并引入聚乙烯吡咯烷酮（PVP）作为结构调控剂，通过分子吸附作用调节晶体生长行为，实现β石英型GeO2纳米晶的可控合成。通过X射线衍射结合Rietveld精修分析发现，原始α-GeO2在溶剂热反应过程中逐渐发生位移型相变，形成六方晶系β石英型结构GeO2的纳米晶，其晶体空间群为P3221。Raman光谱表征结果显示，在486cm⁻¹处出现并显著增强的特征振动峰，表明GeO4四面体结构单元之间的连接方式发生重排，四面体旋转与桥联角度调整使晶体网络趋于更加规则的石英型结构。同时，扫描电子显微镜（SEM）观察结果表明，在反应过程中GeO2晶体形貌经历了明显的演化过程：初始阶段主要为无序团聚的纳米颗粒，随着反应进行，颗粒逐渐发生溶解—再结晶过程，并在PVP分子调控作用下沿特定晶向定向生长，最终形成尺寸分布较为均一的纺锤状或多面体纳米晶结构。研究结果表明，通过溶剂热条件与表面活性分子的协同调控，可以在相对温和的温度条件下实现β石英型GeO2纳米晶的可控制备，并获得形貌均一的纳米结构。本工作不仅为低温条件下石英型氧化物纳米晶的结构调控提供了新的实验思路，同时也为理解有机分子吸附对氧化物纳米晶相变行为与形貌演化的调控机制提供了重要参考，对相关功能氧化物纳米材料的可控制备具有一定的理论意义与应用价值。
Abstract
In this work, commercial -GeO2 powder was used as the precursor to synthesize GeO2 nanocrystals via a solvothermal method at 180. Polyvinyl pyrrolidone (PVP) was introduced as a structure-directing agent to regulate crystal growth behavior through molecular adsorption, enabling the controllable synthesis of -quartz-type GeO2 nanocrystals. X-ray diffraction (XRD) analysis combined with Rietveld refinement indicates that the initial -GeO2 gradually undergoes a displacement-type phase transformation, forming nanocrystals of hexagonal -quartz-type GeO2 with space group P3221. Raman spectroscopy results show a prominent and significantly enhanced characteristic vibration peak at 486 cm, indicating a rearrangement of the connection mode between GeO4 tetrahedral structural units; the rotation of tetrahedra and adjustment of bridging angles lead to a more regular quartz-type crystal network. Meanwhile, scanning electron microscopy (SEM) observations reveal that the morphology of GeO2 crystals undergoes a significant evolution process: initially, the particles are mainly disordered aggregates of nanoscale particles. As the reaction proceeds, particles gradually undergo dissolution-recrystallization processes and, under the regulation of PVP molecules, grow directionally along specific crystallographic orientations, ultimately forming spindle-shaped or polyhedral nanocrystals with relatively uniform size distribution. The results demonstrate that the controllable synthesis of -quartz-type GeO2 nanocrystals with uniform morphology can be achieved under relatively mild temperature conditions through the synergistic regulation of solvothermal conditions and surface-active molecules. This work not only provides a new experimental approach for structural regulation of quartz-type oxide nanocrystals at low temperatures but also offers important insights into the mechanism of organic molecular adsorption on phase transformation and morphological evolution of oxide nanocrystals, with theoretical significance and application value for the controllable preparation of related functional oxide nanomaterials.关键词
氧化锗/纳米颗粒/β石英型GeO2/相变机制/形貌调控Key words
germanium dioxide/nanocrystals/β-quartz-type GeO2/phase transformation mechanism/morphological regulation引用本文复制引用
王欣雨,胡学萍,吴文静,邹旭,赵世华.石英型氧化锗的低温溶剂热制备及其结构演变机制[EB/OL].(2026-09-24)[2026-09-27].https://chinaxiv.org/abs/202609.00308.学科分类
材料科学
