Fig. 3: Electrocatalytic HER performances of RuNi/NC.
a LSVs in 1 M KOH. b Tafel plots in 1 M KOH. c Comparison of overpotentials at 10 mA cm‒2 (η10) in 1 M KOH, 0.5 M H2SO4 and 1 M PBS. d Chronoamperometry for stability tests of RuNi/NC and Pt/C at 10 mA cm‒2 in 1 M KOH without iR-compensation. The testing conditions include RDE surface area: 0.196 cm2, catalyst loading: 0.25 mg cm‒2, rotation rate: 1600 rpm, scan rate: 5 mV s‒1, temperature: 25 °C, electrolyte pH: 13.74 ± 0.12 (1 M KOH), 0.33 ± 0.03 (0.5 M H2SO4), and 7.02 ± 0.02 (1 M PBS), electrolyte resistance: 6.8 ± 0.2 Ω (1 M KOH), 6.2 ± 0.2 Ω (0.5 M H2SO4), 12.1 ± 0.1 Ω (1 M PBS). e LSVs of RuNi/NC || RuO2 and Pt/C || RuO2 for overall water electrolysis. f Chronopotentiometry of RuNi/NC || RuO2 for overall water electrolysis at 10 mA cm−2. The testing conditions include carbon paper electrode surface area: 1 cm2, catalyst loading: 0.25 mg cm‒2, cell configuration: single cell, scan rate: 5 mV s‒1, temperature: 25 °C, electrolyte: 1 M KOH (pH 13.74 ± 0.12), and without iR-compensation. g LSVs of RuNi/NC || RuO2 and Pt/C || RuO2 for chlor-alkali electrolysis. h Chronopotentiometry of RuNi/NC || RuO2 for chlor-alkali electrolysis at 10 mA cm‒2. The testing conditions include electrode surface area: 1 cm2 (carbon paper or low-carbon steel), catalyst loading: 0.25 mg cm‒2, cell configuration: H-type cell, membrane: cation exchange membrane, scan rate: 5 mV s‒1, temperature: 90 °C, electrolytes: saturated NaCl (anolyte, pH 7.01 ± 0.03), and 3 M NaOH and 3 M NaCl (catholyte, pH 14.12 ± 0.11), and without iR-compensation.
