Fig. 3
Crystal structure and electrode HER activity. SAED patterns of a Gd0, b Pr0.5La0.5, c Gd0.5, and d Gd1 perovskites. e HAADF-STEM image and elemental mapping of Gd0.5 sample. Scale bar is 100 nm. f Electrode HER polarization curves of Gd1, Gd0.5, Pr0.5La0.5, Gd0, Pt/C, and Nafion/C catalysts. g Chronopotentiometric curves of Gd0.5, Pr0.5La0.5, and Pt/C materials at 50 mA cm−2disk. h HER activity comparisons of disk current density at −240 mV and Tafel slope between Gd0.5 perovskite and recently reported state-of-the-art electrocatalysts. i Comparisons of TOF values obtained on Gd0.5 material at different overpotentials with those of other well-known HER electrocatalysts
