Triboelectric nanogenerators (TENGs) offer a wide range of applications in self-powered sensor systems. In an article published in the magazine nano energya wave-powered liquid-solid TENG, was developed to provide a self-sufficient detection platform for tracking maritime environmental conditions.
Study: Ethylene chlorotrifluoroethylene/hydrogel-based liquid-solid triboelectric nanogenerator-powered self-powered MXene-based sensor system for marine environment monitoring. Credit: David Prado Perucha/Shutterstock.com
The threats of sulfur dioxide
According to the World Health Organization (WHO), over seven million people die from air pollution every year. Fluctuations in humidity, temperature, and pollution levels can all contribute to the emergence of new contagious diseases; Therefore, these factors need to be tracked in real-time to understand how they vary.
Sulfur dioxide (SO2), a common air pollutant, is very harmful to human health and the ecosystem. Even modest amounts of SO2 can cause lung and heart problems and prolonged SO in humans2 Contact in pregnant women can lead to abnormalities in delivery of the fetus and death.
Sulfur dioxide causes mild acid rain, which damages trees, land and water. Therefore, the development of reliable gas detectors for fast and precise sulfur dioxide measurement is of crucial importance.
Currently, most sulfur dioxide detectors require a power source and some require high temperatures for optimal detection, resulting in significantly high power consumption and cost. Since installing sensors on a large scale requires a lot of energy, novel energy harvesting technologies have to be developed to operate the sensor systems.
Harnessing wave energy with TENGs
Solar and wind power have seen significant development as conventional sources of clean energy. Nonetheless, the generation of solar and wind energy consumes important land resources, which limits their scalable implementation.
The ocean covers over 70% of the surface of this planet and contains many sustainable clean energies such as tidal and wave power. The conversion of wave energy into electricity has emerged as a crucial new focus in energy technology research.
Triboelectric nanogenerators (TENGs) based on triboelectrification and electrostatic interconnection have attracted widespread interest due to their inexpensive nature, diverse component sources, and simple architecture. TENGs offer distinct advantages in capturing low frequency energies (like wave energy).
The liquid-solid TENGs show the way for the generation of wave energy. An important branch of research is the application of TENG-based detection systems in the monitoring of maritime ecosystems. However, current research is limited to basic testing and fails to thoroughly monitor complicated coastal environmental factors such as pollutants.
How can MXenes help?
MXenes are a new class of two-dimensional substances that include carbides, nitrides, and carbonitrides of transition metals and have promising applications in detectors, capacitors, and catalytic processes.
MXenes are used as reducing agents to aid in the graphene oxide (GO) reduction process, further improving gas sensitivity. The self-powered detector has a high sensitivity to NH3 and outstanding specificity. MXenes are used today as gas detectors to detect a variety of gases; However, the use of MXene-based sulfur dioxide detectors has hardly been reported.
Key Findings of the Study
In this research, the team designed a self-sufficient detection system for monitoring the marine environment using a wave-powered liquid-solid TENG. To capture wave energy, the triboelectric nanogenerator was built using ethylene chlorotrifluoroethylene (ECTFE) foils and ionic hydrogel electrodes.
The creation of an atomic-scale electron cloud potential sink and the electric double layer (EDL) elucidated the interfacial electrification between ECTFE and water. The peak-to-peak voltages and idle power density of the TENG could reach 332 V and 1.85 W/m2respectively.
The TENG-powered MXene/TiO2/SnSe detector, which has high sensitivity (about 14 times higher than a resistive sensor), was made for detecting sulfur dioxide gas.
The TENG activated the self-sufficient sulfur dioxide detector, reducing power consumption and significantly improving detector sensitivity. A self-sufficient framework for tracking the marine environment was developed to further illustrate the applicability prospects of the designed TENG and sulfur dioxide detector.
Sensor data from the self-sufficient device can be sent to cellphones and other modules in real time, allowing them to track humidity, temperature, sulfur dioxide gas levels, sea surface levels and other marine environment parameters.
The humidity and temperature debugging of the gas detector was performed by integrating and analyzing the information from the sensor system using a backpropagation neural network framework.
Wang D, Zhang D et al. (2022). Ethylene chlorotrifluoroethylene/hydrogel based liquid-solid triboelectric nanogenerator-powered self-sufficient MXene-based sensor system for marine environment monitoring. nano energy. Available at: https://doi.org/10.1016/j.nanoen.2022.107509