Previously we had developed a microfluidic system that can be easily fabricated by bending a stainless-steel tube into large circular loops. In this study, a fast and continuous preparation method for superfine TiO₂ nanoparticles (TiO₂-NPs) was developed for the aforementioned microfluidic system. The proposed method can yield anatase TiO₂ in 3.5 min, in contrast to the traditional hydrothermal reaction method, which requires hours or even days. Different reaction conditions, such as reaction temperature (120–200 °C), urea concentration (20–100 g/L), and tube length (5–20 m) were investigated. X-ray diffraction and Brunauer-Emmett-Teller analysis indicate that the as-prepared TiO₂-NPs have crystalline sizes of 4.1–5.8 nm and specific surface areas of 250.7–330.7 m²/g. Transmission electron microscopy images show that these TiO₂-NPs have an even diameter of approximately 5 nm. Moreover, because of their small crystalline sizes and large specific surface areas, most of these as-prepared TiO₂-NPs exhibit considerably better absorption and photocatalytic performance with methylene blue than commercial P5 TiO₂ does.

以前，我们已经开发出一种微流体系统，可以通过将不锈钢管弯曲成大的圆形环来轻松地制造该系统。在这项研究中，为上述微流体系统开发了一种快速，连续的制备超细TiO ₂纳米颗粒（TiO ₂ -NPs）的方法。与传统的水热反应方法（需要数小时甚至数天）相比，该方法可在3.5分钟内产生锐钛矿型TiO ₂ 。研究了不同的反应条件，例如反应温度（120–200  °C），尿素浓度（20–100  g / L）和管长（5–20  m）。X射线衍射和Brunauer-Emmett-Teller分析表明，所制备的TiO ₂-NPs的晶体大小为4.1–5.8  nm，比表面积为250.7–330.7 m ² / g。透射电子显微镜图像显示这些TiO ₂ -NP具有约 5nm的均匀直径。而且，由于它们的小晶体尺寸和大的比表面积，大多数这样制备的TiO ₂ -NP比市售P5 TiO ₂表现出明显更好的亚甲基蓝吸收和光催化性能。