K0.4TaO2.4F0.6 Nanocubes as Highly Efficient Noble Metal-Free Electrocatalysts for Hydrogen Evolution Reaction in Acidic Media

- Novel electrocatalysts of K0.4TaO2.4F0.6 NCs/C towards HER have been synthesized by a simple ion exchanged methodology.
- X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies were investigated to prove the charge states and the local electronic structure of K0.4TaO2.4F0.6 NCs/C.
- K0.4TaO2.4F0.6 NCs/gC electrocatalysts exhibit outstanding catalytic activities of overpotential ∼ 100 mV and superior stabilities.
- DFT calculations exhibit that Gibbs free energy decreased by introducing of F.

A novel and simple synthesis methodology based on ion adsorption process is reported for K0.4TaO2.4F0.6 nanocubes supported on carbon (K0.4TaO2.4F0.6 NCs/C), and used as electrocatalyst for hydrogen evolution reaction (HER) in the acidic media. The K0.4TaO2.4F0.6 NCs/C exhibits outstanding catalytic activities and stabilities for HER. The X-ray absorption fine structure (XAFS) analysis indicates stronger binding energy and electron transfer from metal element to fluorine, which leads to higher HER performance, proved by the density functional theory (DFT) calculations.

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