Highly efficient electrocatalytic hydrogen evolution reaction on carbonized porous conducting polymers

Abhishek Lahiri,Guozhu Li,Frank Endres

doi:10.1007/s10008-020-04577-3

Abstract

A rational design of an efficient and inexpensive electrocatalyst for water splitting still remains a challenge. Porous conducting polymers are attractive materials which not only provide a high surface area for electrocatalysis but also absorb light which can be harnessed in photoelectrocatalysis. Here, a novel and inexpensive electrochemical approach is developed to obtain nanoporous conducting copolymers with tunable light absorbance and porosity. By fine-tuning the copolymer composition and upon heat treatment, an excellent electrocatalytic hydrogen evolution reaction (HER) was achieved in alkaline solution with an overpotential of just 77 mV to obtain a current density of 10 mA cm−2. Such an overpotential is remarkably low compared with other reported values for polymers in an alkaline medium. The nanoporous copolymer developed here shows a great promise of using metal-free electrocatalysts and brings about new avenues for exploitation of these porous conducting polymers.

Highlights

Electrocatalytic water splitting is a lucrative process for generating sustainable hydrogen as a fuel
Attempts to make PPP based co-polymers from ionic liquids have not yet been shown. Taking these factors into consideration, in this manuscript, we demonstrate an electrochemical synthesis of porous copolymers based on polythiophene (PTh) and polyparaphenylene (PPP) from an ionic liquid
The copolymerization process occurs at potentials above 1.0 V, and the doping/dedoping processes are not very prominent

Summary

Introduction

Electrocatalytic water splitting is a lucrative process for generating sustainable hydrogen as a fuel. A minimum thermodynamic electrode potential of 1.23 V is needed to split water, with the hydrogen production occurring at 0 V vs standard hydrogen electrode (SHE), only by the use of noble metal catalysts such as Pt and its alloys a low overvoltage close to theoretical value with a high exchange current density and a small Tafel slope is achievable [1,2,3]. In the last two decades, various 3D transition metals such as Co, Fe, Ni, and their alloys, along with their phosphide and sulfide compounds, have shown promising results for HER with low overvoltage [4,5,6] They are susceptible to corrosion in both acidic and alkaline environments

Methods

Results

Conclusion