Fig. 2
The morphology of the nanoporous platinum (graded and constant index Pt layer) electrochemically grown on Si/NiCr/Ti at four different electrolysis times (from left to right: t1 = 10s, t2 = 30s t3 = 40 s, t4 = 60 s). (a–d) Top view SEM images of the four samples which are labeled t1, t2, t3, and t4. (e–l) 2D (e–h) and 3D (i–l) height SPM image of the samples t1, t2, t3, and t4. The substrates for electrolysis of 0.5% PtCl4 are 1.5 cm x1.5 cm Si chips sputtered with highly reflecting 100 nm thick NiCr and 5 nm thick Ti layer. SEM and SPM scale bar: 2 μm.
