Graphene oxide nanosheet-supported Pt concave nanocubes with high-index facets for high-performance H2O2 sensing

Abstract

As is known, the catalytic activity of metal nanocrystals is strongly affected by their size and shape, and the shape has a greater impact. Among them, metal nanocrystals enclosed by high-index facets have attracted significant attention due to their excellent properties. In this study, platinum concave nanocubes (Pt CNC) with different sizes and angles distributed on polyvinyl pyrrolidone-functional graphene oxide (GO) were synthesized by a one-pot hydrothermal process. The platinum concave nanocubes mainly enclosed by {410}, {510}, and {610} were prepared and used as modified glassy carbon electrodes; cyclic voltammetry and chronoamperometry were applied to investigate the difference between the catalytic activities of platinum concave nanocubes with different facets. The electrodes induced efficient electrocatalysis of hydrogen peroxide (H₂O₂), and the electrode modified with Pt CNC/rGO-220 showed the highest reduction current. H₂O₂ was detected with a detection limit of 0.7 μM over two wide linear ranges (from 3 μM to 1 mM and from 1 mM to 0.1 M) and with high sensitivities (757.4 μA mM⁻¹ cm⁻² and 315.4 μA mM⁻¹ cm⁻²), respectively. The modified glassy carbon electrodes also exhibited good stability and selectivity.