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 IrO2 or Pt nanoparticles at its surface by simple wet-chemical methods. These IrO2 and Pt-loaded SnO2 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 NH3-TPD analysis. The electrochemical water splitting measurements of the IrO2 and Pt doped mesoporous SnO2 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 IrO2@MTO-S and Pt@MTO-S nanocomposites, respectively. As a result, the IrO2@MTO-S modified electrode exhibits unprecedented OER activity with a very low overpotential of 240mV at 10mAcm(-2), which is lower than the state-of-the-art catalyst IrO2/C (360mV) and other reported catalysis. Pt@MTO-S also exhibit excellent HER activity with an ultralow overpotential of 73mV at 10mAcm(-2). These findings may uncover new opportunities for IrO2@MTO-S and Pt@MTO-S as OER and HER electrocatalysts for future water electrolysis.