Interfacial engineering of holey platinum nanotubes for formic acid electrooxidation boosted water splitting

Abstract

Both structure and interface engineering are highly effective strategies for enhancing the catalytic activity and selectivity of precious metal nanostructures. In this work, we develop a facile pyrolysis strategy to synthesize the high-quality holey platinum nanotubes (Pt-H-NTs) using nanorods-like PtII-phenanthroline (PT) coordination compound as self-template and self-reduction precursor. Then, an up-bottom strategy is used to further synthesize polyallylamine (PA) modified Pt-H-NTs (Pt-H-NTs@PA). PA modification sharply promotes the catalytic activity of Pt-H-NTs for the formic acid electrooxidation reaction (FAEOR) by the direct reaction pathway. Meanwhile, PA modification also elevates the catalytic activity of Pt-H-NTs for the hydrogen evolution reaction (HER) by the proton enrichment at electrolyte/electrode interface. Benefiting from the high catalytic activity of Pt-H-NTs@PA for both FAEOR and HER, a two-electrode FAEOR boosted water electrolysis system is fabricated by using Pt-H-NTs@PA as bifunctional electrocatalysts. Such FAEOR boosted water electrolysis system only requires the operational voltage of 0.47 V to achieve the high-purity hydrogen production, showing an energy-saving hydrogen production strategy compared to traditional water electrolysis system.