Poly(3,4-ethylenedioxythiophene) (PEDOT) As an Electrocatalyst for Water Splitting: From Fundamental Insights to Practical Applications in Sustainable Hydrogen Production
Authors: Reddy Jeygeerthika Nagendran , Prabakar Kandasamy 
Published: August 2024

Poly(3,4-ethylenedioxythiophene) (PEDOT) has recently emerged as a highly promising and versatile electrocatalyst for water splitting, a pivotal process in the realm of renewable energy conversion. This review comprehensively explores the multifaceted aspects of PEDOT's electrocatalytic prowess, covering its intrinsic properties, synthetic methodologies, catalytic mechanisms, and practical applications in the context of water electrolysis. PEDOT, [C2H4O2C4H2S]n a conductive polymer, exhibits unique features that render it particularly suitable for electrocatalysis. With its excellent electrical conductivity, notable stability, and facile synthesis, PEDOT stands out among its counterparts. These attributes make PEDOT an attractive candidate for addressing the challenges associated with the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), the two half-reactions constituting water splitting.

One of the key advantages of PEDOT lies in its high surface area, which allows for increased active sites for catalysis. The tunable redox states of PEDOT further contribute to its electrocatalytic versatility, enabling tailored catalytic performance through controlled doping and modifications. The efficient charge transport properties of PEDOT are crucial for facilitating electron transfer during the electrocatalytic processes, ensuring high catalytic activity. This review delves into the simple fabrication of PEDOT-based electrocatalysts. Researchers have explored various strategies, including morphological control, doping with heteroatoms, and integration into composite materials, to enhance the catalytic performance of PEDOT. The rational design of PEDOT structures has demonstrated the potential to surpass the limitations of traditional electrocatalysts and unlock new avenues for efficient water splitting.

In elucidating the mechanistic aspects of PEDOT's catalytic activity, the review investigates the intricate interplay of surface interactions, redox reactions, and mass transport phenomena. Understanding the fundamental principles governing PEDOT's electrocatalytic behavior is essential for optimizing its performance and guiding further developments in this burgeoning field. Simple electrodeposition method is carried out to polymerize EDOT. Cyclic voltammetry method was used for synthesizing PEDOT on nickel foam. Then the sample was heated at differnet temperatures.

Hydrogen Evolution Reaction (HER) Overpotential:

An overpotential of 170 mV at 10 mA/cm² is observed for the HER which indicates that PEDOT as an effective in catalyzing the reduction of protons to form hydrogen gas. A lower overpotential implies that PEDOT facilitates the electrochemical reaction at a lower energy input, showcasing its efficiency as an electrocatalyst for hydrogen production.

Oxygen Evolution Reaction (OER) Overpotential:

The PEDOT exhibits an overpotential of 300 mV at 10 mA/cm² for the OER which suggests its enhanced performance in catalyzing the oxidation of water to produce oxygen gas. While this overpotential is higher than that for the HER, it is still within a range that indicates good catalytic activity for the challenging OER.

Surpassing Many Catalyst Behaviors:

PEDOT's performance, as indicated by its low overpotentials, exceeds that of many other catalysts commonly used for water splitting reactions. This could include traditional metal-based catalysts or other conductive polymers, highlighting PEDOT's potential as a superior electrocatalyst. More electrochemical studies have been taken to prove practical application for PEDOT while the reported overpotentials are promising, and additional research and experimentation are being conducted to validate and understand PEDOT's practical application in real-world scenarios. This involve studying its stability over time, scalability, and compatibility with alkaline electrolyte systems and operational conditions.

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