doi:10.1038/nindia.2018.30 Published online 14 March 2018
Researchers have synthesised a new kind of catalyst that can efficiently help produce oxygen by splitting water1. Splitting water also generates hydrogen, making the catalyst potentially useful for yielding clean fuel.
An oxygen-generating reaction is a key process that keeps metal-air batteries, fuel cells and solar cells functioning. However, this reaction is slow. Metal-oxide-based catalysts used to accelerate this reaction are expensive and generate an oxide layer that reduces the conductivity of batteries and fuel cells.
To find an efficient catalyst, scientists from the CSIR-Central Electrochemical Research Institute in Karaikudi, Tamil Nadu, led by Subbiah Alwarappan, prepared the catalyst by using nickel-nanoparticle-loaded modified graphene nanoribbons. They then explored the catalyst’s potential to catalyse an oxygen-generating reaction.
Increasing the amount of nickel in the catalyst significantly increased its catalytic activity at a low voltage. This shows that nickel present in the graphene nanoribbons played a vital role in catalysing the oxygen-generating reaction.
The catalyst retained its catalytic efficiency over a period of 10 hours at a steady current density. Such stability can be attributed to a closely packed structure in which nickel nanoparticles are encapsulated in the matrix of graphene nanoribbons. It can also be employed as an enzyme-free catalyst in various biosensors, says Alwarappan.
1. Joy, J. et al. Nickel-incorporated, nitrogen-doped graphene nanoribbons as efficient electrocatalysts for oxygen evolution reaction. J. Electrochem. Soc. 165 (2018) doi: 10.1149/2.0601803jes