Size Effects of Pt Nanoparticle/Graphene Composite Materials on the Electrochemical Sensing of Hydrogen Peroxide

The electrochemical detection of hydrogen peroxide (H₂O₂) has attracted much attention recently. Meanwhile, the size of nanoparticles which significantly influences electrocatalytic activity is crucial for electrocatalysts. Hence, we prepared five different size-selected Pt/graphene-modified glassy carbon (GC) electrodes to characterize H₂O₂ level via electrochemical measurements. During the preparation of the nanocomposites, size-selected Pt nanoparticles (NPs) with the mean diameter of 1.3, 1.7, 2.9, and 4.3 nm were assembled onto the graphene surfaces. The electrochemical measurement results are size-dependent for Pt NPs when sensing H₂O₂. When all cyclic voltammogram results from various electrodes are compared, the Pt-1.7 nm/G-modified GC electrode has the highest reduction current, the best detection limit, and the best sensitivity.