Characterization and OER test dataset of NiS2 coupling with ferrous phosphite and phosphide

A graphite rod (with a diameter of 6 mm) was used as the counter electrode, a Ag/AgCl electrode was used as the reference electrode and the as prepared catalyst coating on carbon paper was employed as the working electrode. The OER catalytic activity was gained by using linear sweep voltammetry (LSV) with a scan rate of 5 mV s-1 and the Tafel slope was calculated from the LSV data. Electrochemical impedance spectroscopy (EIS) was performed with a frequency from 100 kHz to 0.1 Hz at a constant potential.

Long-term stability tests were performed by cyclic voltammetry scans at a sweep rate of 10 mV s-1 for 2500 cycles, chronoamperometry measurements at an h of 220 mV for 160 h and chronopotentiometry tests at a current density of 10 mA cm-2 for 130 h. All test data were iR-compensated (95%) and not otherwise specified. All measured potentials vs. the Ag/AgCl electrode were switched to the potentials vs. RHE using the following Nernst equation: ERHE = EAg/AgCl + 0.0591pH + 0.197 V.