Precise regulation of the multicolor spectrum of carbon dots based on the bionic leaf vein ultrasonic microreactor

Longshi Rao; Bin Sun; Yang Liu; Qing Zhang; Guisheng Zhong; Mingfu Wen; Jiayang Zhang; Ting Fu; Xiaodong Niu

doi:10.1016/j.ultsonch.2023.106674

Precise regulation of the multicolor spectrum of carbon dots based on the bionic leaf vein ultrasonic microreactor

Ultrason Sonochem. 2023 Dec:101:106674. doi: 10.1016/j.ultsonch.2023.106674. Epub 2023 Nov 2.

Authors

Longshi Rao¹, Bin Sun², Yang Liu², Qing Zhang², Guisheng Zhong³, Mingfu Wen², Jiayang Zhang², Ting Fu⁴, Xiaodong Niu²

Affiliations

¹ Department of Mechanical Engineering, College of Engineering, Shantou University, Shantou 515063, China; Intelligent Manufacturing Key Laboratory of Ministry of Education, Shantou University, Shantou 515063, China; Guangdong Provincial Key Laboratory of Automotive Display and Touch Technologies, Shantou Ultrasonic Display Technology Co., Ltd., Shantou 515041, China. Electronic address: lsrao@stu.edu.cn.
² Department of Mechanical Engineering, College of Engineering, Shantou University, Shantou 515063, China; Intelligent Manufacturing Key Laboratory of Ministry of Education, Shantou University, Shantou 515063, China.
³ Department of Mechanical Engineering, College of Engineering, Shantou University, Shantou 515063, China; Intelligent Manufacturing Key Laboratory of Ministry of Education, Shantou University, Shantou 515063, China. Electronic address: gszhong@stu.edu.cn.
⁴ Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan 430081, China.

Abstract

Carbon dots (CDs) are a fascinating new type of fluorescent carbon nanomaterial with excellent photoelectric properties. However, preparing long-wavelength and multicolor-emitting CDs has been challenging, limiting their large-scale applications. Fortunately, a new efficient method has been proposed to co-regulate CDs' multicolor spectra using an ultrasonic microreactor. Inspired by plant leaves, a bionic vein microchannel was designed with good fluidity and high energy transfer efficiency. The optimal microchannel structural parameters were determined after investigating the effects of fractal angle, depth-to-width ratio, and inlet angle on the flow uniformity of the microchannel using numerical simulations. The efficiency of ultrasonic energy transfer was improved by directly coupling the microreactor and the sandwich transducer to fabricate the ultrasonic microreactor. Simulation results showed that the ultrasonic microreactor's vibration resonated along the longitudinal direction, and the ultrasonic intensity of the microreactor was maximal and uniform. A high-efficiency and controllable ultrasonic microreactor system was built to synthesize the CDs in situ. The influence of the ultrasound field intensity on CDs' preparation in a microreactor was simultaneously investigated to verify the ultrasound enhancement, and the PLQY of the high-performance CDs was found to be 83.1%. The CDs' multicolor spectra from the blue to the red region can be precisely tuned by adjusting key reaction parameters such as reaction temperature, flow rate, and precursor concentration. This new method shows promising applications in lighting, display, and other fields, making CDs a versatile and exciting new material to explore.