Bowl-shaped electrode acts like electrochemical leaf

"Just as plants transform CO2 into sugar, we are finding a suitable electrochemical 'leaf' for CO2 conversion."Liwu Zhang, Fudan University

A team of scientists has created a bowl-shaped electrode catalyst with 'hot edges' that can efficiently convert carbon dioxide (CO₂) into carbon-based fuels and chemicals, helping combat the climate change threat posed by atmospheric CO₂. The scientists report their work in a paper in the Journal of Materials Chemistry A.

The team comprises scientists from the University of Bath in the UK, and from Fudan University and the Shanghai Institute of Pollution Control and Ecological Security, both in China. They hope the electrode design will eventually allow the use of renewable electricity to convert CO₂ into fuels without creating additional atmospheric CO₂ – essentially acting like an electrochemical 'leaf'.

Known as CO₂ reduction, this reaction has exciting potential, but two major obstacles stand in its way. These are a poor conversion efficiency and a lack of detailed knowledge about the exact reaction pathway.

This new electrode catalyst addresses these challenges by providing a higher conversion efficiency and allowing sensitive detection of the molecules created during the reaction's progress – all thanks to its innovative shape and construction. The bowl-shaped electrode, made from a copper-indium alloy, works six times faster than standard planar – or flat – designs.

The bowl-like shape of the electrode, technically known as an ‘inverse opal structure’, concentrates electric fields at its hot edges – the rim of the bowl. These electric fields concentrate positively charged potassium ions on the active sites of the electrode, reducing its energy requirements. The electrode can also be useful for sensitively studying the reaction process via measuring its Raman signal, which is higher compared to a typical electrode.

"There is no more pressing human need than breathing. Yet for hundreds of million people this most basic activity is a source of anxiety over lowering life expectancy, rising child mortality and climate change," said Ventsislav Valev from the University of Bath's Department of Physics. "There is evidence that CO₂ increases surface ozone, carcinogens and particulate matter, thereby increasing death, asthma, hospitalization and cancer rates. It is therefore crucial to keep researching new ways for lowing the CO₂ levels in the atmosphere."

The team wants to continue its research into developing the most efficient catalyst for performing CO₂ reduction.

"CO₂ is causing climate change, making our planet warmer," said Liwu Zhang from Fudan University. "By using clean electricity, we can convert CO₂ into chemical fuels, which can be used again. This builds a cycle of CO₂, with no increment of CO₂ concentration and will help save our world.

"However, to improve the efficiency of transforming CO₂ into chemical fuels, it is extremely important to know the reaction pathway, and find the most suitable catalyst. Just as plants transform CO₂ into sugar, we are finding a suitable electrochemical 'leaf' for CO₂ conversion."

This story is adapted from material from the University of Bath, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.