IrO2 and Pt Doped Mesoporous SnO2 Nanospheres as Efficient Electrocatalysts for the Facile OER and HER

Abstract Electrocatalytic hydrogen and oxygen evolutions via water splitting are very demanding in the context of renewable energy and sustainable environment. We first report the synthesis of wormhole‐like mesoporous tin oxide (MTO‐S) by using sodium lauroyl sarcosinate as structure directing agent under hydrothermal reaction conditions followed by calcination and loading with IrO 2 or Pt nanoparticles at its surface by simple wet‐chemical methods. These IrO 2 and Pt‐loaded SnO 2 nanomaterials are thoroughly characterized by small and wide‐angle powder XRD, nitrogen adsorption/desorption analysis, FTIR, XPS spectroscopy, UHR‐TEM, FE‐SEM, TG/DTA and NH 3 ‐TPD analysis. The electrochemical water splitting measurements of the IrO 2 and Pt doped mesoporous SnO 2 nanostructured materials suggested fine dispersion of these metal/metal oxide nanoparticles at the mesopore surface and facile electron hopping could enhance the rate of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activity of IrO 2 @MTO‐S and Pt@MTO‐S nanocomposites, respectively. As a result, the IrO 2 @MTO‐S modified electrode exhibits unprecedented OER activity with a very low overpotential of 240 mV at 10 mA cm −2 , which is lower than the state‐of‐the‐art catalyst IrO 2 /C (360 mV) and other reported catalysis. Pt@MTO‐S also exhibit excellent HER activity with an ultralow overpotential of 73 mV at 10 mA cm −2 . These findings may uncover new opportunities for IrO 2 @MTO‐S and Pt@MTO‐S as OER and HER electrocatalysts for future water electrolysis.