Rapid laser synthesis of surfactantless tantalum‐based nanomaterials as bifunctional catalysts for direct peroxide–peroxide fuel cells

Abstract

AbstractEfficient and durable electrocatalysts are instrumental in enabling next‐generation fuel cell technologies. At present, expensive precious metals are used as state‐of‐the‐art catalysts. In this report, cost‐effective nanosized tantalum‐based alternatives are synthesized for the first time via a green and scalable laser pyrolysis method as bifunctional catalysts for direct peroxide–peroxide fuel cells. This rapid laser pyrolysis strategy allows for the production of nanoparticles at a laboratory scale of grams per hour, compatible with a detailed exploration of the functional properties of as‐synthesized nanoparticles. By varying the precursor ratio between ammonia and tantalum ethanolate, five tantalum‐based nanomaterials (TaNOC) are prepared with crystalline phases of Ta2O5, Ta4N5, Ta3N5, and TaN in tunable ratios. Electrochemical studies in neutral and alkaline conditions demonstrate that Ta4N5 is the active component for both H2O2 oxidation and reduction. Kinetic isotope effect studies show that protons are involved at or before the rate‐determining step. Long‐term stability studies indicate that Ta3N5 grants surfactant‐free TaNOC‐enhanced longevity during electrocatalytic operations. Taken together, bifunctional TaNOC can act as active and robust electrocatalysts for H2O2 reduction and oxidation. Laser pyrolysis is envisioned to produce refractory metal nanomaterials with boosted corrosion resistance for energy catalysis.