Hollow spheres made from titanium dioxide (TiO2) are interesting structures because of their high surface area and low density, combined with semiconducting properties of the TiO2. However, the synthesis is still challenging because of the high reactivity of the titania precursors. Here, we present a simple, reproducible, and scalable way to synthesize TiO2 hollow spheres in the micrometer/sub-micrometer size range comprising three steps: synthesis of polystyrene template particles, growth of TiO2 shells, and calcination to hollow spheres. We investigate the importance of adjusting the seed particle surface functionalization via the appropriate choice of comonomer during the dispersion polymerization. An aging step and a calcination process at low temperatures are mandatory to retain the particle integrity during the seed particle removal. We provide a detailed characterization of each step of this process including electron microscopy, small angle X-ray scattering, and simultaneous thermal analysis. Graphical abstract Graphical abstract

中文翻译：

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（亚）微米尺寸范围内光滑 PS@TiO2 核壳和 TiO2 空心球的可扩展合成：了解合成和煅烧参数

由二氧化钛 (TiO2) 制成的空心球是一种有趣的结构，因为它们具有高表面积和低密度，再加上 TiO2 的半导体特性。然而，由于二氧化钛前体的高反应性，合成仍然具有挑战性。在这里，我们提出了一种简单、可重复和可扩展的方法来合成微米/亚微米尺寸范围内的 TiO2 空心球，包括三个步骤：聚苯乙烯模板颗粒的合成、TiO2 壳的生长和煅烧成空心球。We investigate the importance of adjusting the seed particle surface functionalization via the appropriate choice of comonomer during the dispersion polymerization. 必须在低温下进行老化步骤和煅烧过程，以在去除种子颗粒期间保持颗粒完整性。我们提供了该过程每个步骤的详细表征，包括电子显微镜、小角度 X 射线散射和同步热分析。图形摘要图形摘要