A novel method for fast and continuous preparation of superfine titanium dioxide nanoparticles in microfluidic system--颗粒学报PARTICUOLOGY

Deng, N., Wang, Y., & Luo, G. (2022). A novel method for fast and continuous preparation of superfine titanium dioxide nanoparticles in microfluidic system. Particuology, 60, 61-67. https://doi.org/10.1016/j.partic.2021.04.015

A novel method for fast and continuous preparation of superfine titanium dioxide nanoparticles in microfluidic system

Nan Deng, Yujun Wang ^*, Guangsheng Luo

State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China

10.1016/j.partic.2021.04.015

Volume 60, January 2022, Pages 61-67

Received 15 March 2021, Revised 26 April 2021, Accepted 27 April 2021, Available online 12 May 2021, Version of Record 23 October 2021.

E-mail: wangyujun@mail.tsinghua.edu.cn

Highlights

• Fast and continuous synthesis of anatase TiO₂ nanoparticles in 3.5 min.

• Simply using a homemade microfluidic system consisted of stainless steel tube.

• Utilizing cheap and environment-friendly inorganic raw materials.

• Particle sizes as small as about 5 nm and specific surface area up to 330 m₂/g.

• High photocatalytic performance with the maximum rate 2.1 times of commercial P5.

Abstract

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.

Graphical abstract

Keywords

Titanium dioxide; Microfluidic system; Nanoparticles; Fast preparation; Superfine

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