D 2020 nafion solution

Electrocatalyst support was implemented in a three-electrode system. A round working electrode with an area of 1.5 cm² was prepared as follows: Ag/AgCl, carbon graphite, and a Pt strip were used as the reference, relative, and counter electrode, respectively. The electrochemical test was performed in a potentiostat/galvanostat (Autolab-PGSTAT 30 Eco Chemie, KM Utrecht, The Netherlands) in 0.1 M KOH_(aq) solution, and C–V curves were obtained from −0.2 to 1.0 V at a scanning rate of 50 mV·s⁻¹. The catalyst ink was prepared by combining 2.9 mg Co-N-C catalyst powder with a mixture of 375 μL of ethanol and 375 μL of deionized water and stirring until uniform. Subsequently, 7.14 μL of 5% D-2020 Nafion solution (Merck, Darmstadt, Germany) was introduced into the mixture as a binder, the mixture was ultrasonicated for 1 h, and 5μL of the obtained ink was uniformly spray-coated on the carbon paper for C-V testing.
The current–potential polarization curves obtained from the LSVs of the various Co-N-C catalysts were measured using a rotating-disk electrode (RDE: Metrohm, Tampa, FL, USA) operating at 900, 1200, 1600, 2500, and 3600 rpm, respectively, in O₂-saturated 0.1 M KOH_(aq). The reduction current densities of various Co-N-C catalysts, which were recorded at 1600 rpm with 5 mV s⁻¹ scanning speed within the measured voltage range (0.0~1.2 V), were chosen for comparison.

The performance of the electrocatalyst support was implemented in a three-electrode system. The round working electrode, which had an area of 1.5 cm², was prepared as follows: Ag/AgCl, carbon graphite, and a Pt-strip were used as the reference, relative, and counter electrode, respectively. The electrochemical test was performed in a potentiostat/galvanostat (Autolab-PGSTAT 30 Eco Chemie, KM Utrecht, The Netherlands) in 0.1 M KOH_(aq) solution, and C–V curves were obtained from −0.2 to 1.0 V at a scanning rate of 50 mV s⁻¹. The catalyst ink was prepared by mixing 2.9 mg support powder in isopropanol and stirring until uniform. Subsequently, 5% D-2020 Nafion solution (Merck, Darmstadt, Germany) was introduced into the mixture as a binder, the mixture was ultra-sonicated for 1 h, and the obtained ink was uniformly spray-coated on the carbon paper for C-V testing.
The current–potential polarization curves obtained from LSV of the various CoNCs were measured using a rotating-disk electrode (RDE: Metrohm, Tampa, FL, USA) operating at 900, 1200, 1600, 2500, and 3600 rpm in O₂-saturated 0.1 M KOH_(aq), respectively. The reduction current densities of various CoNCs, which were recorded at 1600 rpm with 5 mV s⁻¹ scanning speed within the measured voltage range (0.0~1.0 V), were chosen for comparison.