Hybrid Electrocatalyst Architectures: Aren’t we just modulating the Fermi Level?

Hybrid Electrocatalyst Architectures: Aren’t we just modulating the Fermi Level?

 

The Integrated Materials Design Centre at UNSW Australia publishes an important theoretical analysis in ACS Catalysis of the role of electron transfer and Fermi level modulation in hybrid electrocatalyst materials used for the formation of hydrogen from water.

Forming hydrogen from water is an incredibly important process, since hydrogen is an ideal energy storage reservoir as a clean burning fuel. Excess electrical power generated from volatile sources (e.g. solar or wind) can be utilized to store the energy as hydrogen. Hybrid electrocatalyst systems involving an active layer of graphitic carbon nitride (g-C3N4) on a conductive substrate of nitrogen(N)-doped graphene (g-C3N4@NG) have been shown to achieve excellent efficiency for the hydrogen evolution reaction (HER). The IMDC here uses first principle calculations to derive a more general modulation doping strategy - by which either electron donating (“n-doping” – a raised Fermi level) or electron withdrawing (“p-doping” – a depressed Fermi level) features induced in the graphene substrate can be exploited to promote the HER on the g-C3N4 active layer. Using this principle, the study predicts that boron (B) may be the most promising doping element for the graphene substrate in these hybrid electrocatalyst systems.

Here, the high performance materials modelling at the IMDC provides a more general principle for rational design of hybrid electrocatalysts, via manipulation of the Fermi level of the underlying conductive substrate.