Abstract TiO2 hollow nanoparticles with tunable cavity size were prepared via a microwave-assisted hydrolysis reaction between TiCl4 and different amounts of HF aqueous solution, followed by calcination at 400 °C for 2 h. The obtained TiO2 hollow nanoparticles with tunable cavity size were characterized with TEM, SEM, XRD, Raman, BET, UV–vis absorption spectra, and photocurrent measurement. It was found that the tunable cavity size of TiO2 hollow nanoparticles was apparently enlarged from 1 to 3 nm to 7–9 nm by increasing the content of HF, and that HF also plays a crucial role in the crystallization of TiO2. The TiO2 hollow nanoparticles exhibit the unique cavity-size-dependent properties of UV absorption and photocatalytic activity for acetone degradation. This study offers a novel approach to fabricating TiO2 hollow nanoparticles with tunable cavity size, and the unique cavity-size-dependent photocatalytic property has potential for wide popularization and application prospects.

中文翻译：

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腔尺寸可调的 TiO2 中空纳米粒子的制备和腔尺寸依赖性光催化性能

摘要 通过 TiCl4 与不同量的 HF 水溶液之间的微波辅助水解反应，然后在 400 °C 下煅烧 2 h，制备了具有可调腔尺寸的 TiO2 中空纳米粒子。通过TEM、SEM、XRD、拉曼、BET、UV-vis吸收光谱和光电流测量对获得的具有可调腔尺寸的TiO2中空纳米粒子进行表征。结果表明，通过增加 HF 含量，TiO2 中空纳米粒子的可调腔尺寸明显从 1-3 nm 扩大到 7-9 nm，并且 HF 在 TiO2 的结晶过程中也起着至关重要的作用。TiO2 中空纳米粒子表现出独特的腔尺寸依赖性，如紫外线吸收和丙酮降解的光催化活性。