Figure 3: In situ electrical transport spectroscopy (ETS) of the PtNWs.
(a) IG–VG (black curve) and normalized GSD–VG (red curve) characteristics of a typical PtNWs device. IG–VG resembles the typical CV characteristic of a polycrystalline Pt surface, containing redox regions of hydrogen evolution reaction (HER), H adsorption/desorption region (Hupd), double layer (DL) region, surface oxide formation/reduction region (Oupd) and oxygen evolution reaction (OER). GSD–VG (ETS) curve can also be divided into three regions marked with yellow, green and purple boxes correspondingly. (b) Differentiated ETS (DETS) curve shows spectral peak characteristics. Red curve is a 15-point-averaged result for visual guide of the differentiated data. (c) Schematic illustrations of different Pt surface conditions with the sweeping electrochemical potentials (left black axis) and the corresponding conductivity changes (right red axis, labels shown along the axis are corresponding to the labels shown on GSD curve in a). Pt atoms are grey, H atoms are white, O atoms are red in H2Oads, blue in OHads and green in Oads for visual guide to the different scattering effect. Arrows in all figures indicate the potential sweeping direction, with corresponding dots showing the starting point of measurement.
