Sustainable and Clean Energy Harvesting Device Using Reversible Redox Reactions Driven Alternately by Light and...

Area of Science:

• Materials Science
• Energy Harvesting
• Electrochemistry

Background:

• Environmental energy sources like moisture and solar irradiation are crucial for next-generation power generators.
• Challenges exist in harnessing dual stimuli due to irregular distribution and short power generation duration of existing devices.
• Developing sustainable energy solutions requires innovative approaches to complementary energy utilization.

Purpose of the Study:

• To demonstrate a sustainable energy generator alternately powered by moisture and light (MLG).
• To address the limitations of short power generation duration in existing moisture-driven power generators.
• To explore the potential of an asymmetric [Fe(CN)6]3-/4- redox couple in a hygroscopic hydrogel for continuous energy harvesting.

Main Methods:

• An asymmetric design incorporating a [Fe(CN)6]3-/4- redox couple within a hygroscopic hydrogel was developed.
• The MLG device operates by alternating between moisture-only and combined light-moisture effects, utilizing photothermal energy.
• Forward and reverse redox reactions were driven by alternating moisture and light stimuli to generate alternating current.

Main Results:

• The MLG device achieved peak outputs of 3.2 mA current and 0.23 V voltage under 98% relative humidity (RH).
• Illumination effectively restored moisture-triggered current, recovering it to 166 µA after decay.
• The system exhibited exceptional cycling stability under repeated light-moisture alternations.

Conclusions:

• The demonstrated MLG offers a sustainable approach to energy harvesting by complementary utilization of environmental energy.
• The device overcomes the short power generation duration issue, providing continuous alternating current output.
• This technology holds significant potential for powering small electronic devices and sensors using readily available environmental stimuli.