Large‐scale synthesis of centrifugally spun tantalum oxynitride fiber electrocatalysts for hydrogen evolution reaction

Abstract

AbstractTantalum oxynitride (TaOxN1−x) fibers were synthesized and evaluated for their electrocatalytic hydrogen activity using an in‐house developed centrifugal spinning setup. By tailoring the composition of the spinning solution and optimizing collector distance and rotation speed of the spinneret, bead‐free TaOxN1−x fibers with a diameter of 800 nm were obtained. The fibers were structurally characterized through phase and elemental analysis, confirming the formation of monoclinic TaOxN1−x with clear splitting of the X‐ray photoelectron spectroscopy peaks indicating Ta was in +5 oxidation state. The resulting oxynitride fibers exhibited superior electrocatalytic performance with low overpotentials (250 mV) to generate 10 mA/cm2 compared to Ta2O5 oxide fibers. Interestingly, the enhanced activity of oxynitride fibers was observed to be suppressed in basic medium due to the high oxophilicity of tantalum ions and a negative Gibbs adsorption‐free energy, leading to poisoning of the active sites. This work demonstrates a facile pathway for the fabrication of high‐performance electrocatalysts, based on TaOxN1−x fibers, from a cost‐effective and energy‐efficient centrifugal spinning technique.