J. Mater. Sci. Technol. ›› 2021, Vol. 76: 33-40.DOI: 10.1016/j.jmst.2020.11.002

• Research Article • Previous Articles     Next Articles

Self-powered/self-cleaned atmosphere monitoring system from combining hydrovoltaic, gas sensing and photocatalytic effects of TiO2 nanoparticles

Tianyan Zhong1, Huangxin Li1, Tianming Zhao, Hongye Guan, Lili Xing*(), Xinyu Xue*()   

  1. School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
  • Received:2020-04-14 Revised:2020-08-18 Accepted:2020-09-04 Published:2021-06-20 Online:2020-11-06
  • Contact: Lili Xing,Xinyu Xue
  • About author:xuexinyu@mail.neu.edu.cn(X. Xue).
    *E-mail addresses: xinglili@uestc.edu.cn (L. Xing),
    First author contact:

    1These authors contributed equally to this work.


A new self-powered/self-cleaned atmosphere monitoring system has been fabricated from TiO2 nanoparticles through combining hydrovoltaic, gas sensing and photocatalytic effects. The TiO2 nanoparticle film can convert natural thermal energy into electricity (hydrovoltaic effect) by the spontaneous water evaporation. The hydrovoltaic/gas-sensing coupling effect of TiO2 nanoparticle offers the water-evaporation-powered gas detection performance, and the outputting voltage/current has a good response to the surrounding gas atmosphere, directly acting as the gas sensing signal. The zeta potential of TiO2 is changed by the surface adsorption of gas molecules, and thus affects the electricity output of the system. The outputting electricity can directly power a wireless transmitter for transmitting the sensing information to external platform, and the whole system can work independently without electricity power supply. The rainwater can be used as the fuel of the system, and thus the system can be used outdoors without scheduled maintenance. Moreover, the photocatalytic activity of TiO2 can effectively degrade the organic pollutants on the film under photo illumination, leading to a self-clean behavior of the system. The system can probably promote the development of green sensing techniques with evaporation-induced ability.

Key words: TiO2 nanoparticles, Self-powered, Self-cleaned, Hydrovoltaic effect, Gas sensor