Iron-Containing Nickel Cobalt Sulfides, Selenides, and Sulfoselenides as Active and Stable Electrocatalysts for the Oxygen Evolution Reaction in an Alkaline Solution

Iron-containing nickel sulfides, selenides, and sulfoselenides were synthesized via a simple two-step hydrothermal reaction (temperature <= 160 degrees C) for their application as electrocatalysts in the oxygen evolution reaction (OER) in an alkaline solution (1 mol L-1 KOH). The study demonstrated that iron-containing nickel cobalt sulfides and selenides exhibit superior OER performance with lower overpotentials compared to iron-free nickel cobalt sulfide and selenide, which highlights the significant role of iron in enhancing OER nickel cobalt electrocatalysts: Fe0.1Ni1.4Co2.9(S0.87O0.13)(4), eta(50) = 318 mV; Fe0.2Ni1.5Co2.8(S0.9O0.1)(4), eta(50) = 310 mV; Fe0.3Ni1.2Co2.5(S0.9O0.1)(4), eta(50) = 294 mV; Fe0.6Ni1.2Co2.5(S0.83O0.17)(4), eta(50) = 294 mV; Fe0.4Ni0.7Co1.6(Se0.81O0.19)(4), eta(50) = 306 mV compared to Ni1.0Co2.1(S0.9O0.1)(4), eta(50) = 346 mV; and Ni0.7Co1.4(Se0.85O0.15)(4), eta(50) = 355 mV (all values at current densities eta(50) of 50 mA cm(-2)). Furthermore, the iron-containing nickel cobalt sulfoselenide Fe0.5Ni1.0Co2.0(S0.57Se0.25O0.18)(4) displayed exceptional OER performance with eta(50) = 277 mV, surpassing the benchmark RuO2 electrode with eta(50) = 299 mV. The superior performance of the sulfoselenide was attributed to its low charge transfer resistance (Rct) of 0.8 Omega at 1.5 V vs. the reversible hydrogen electrode (RHE). Moreover, the sulfoselenide demonstrated remarkable stability, with only a minimal increase in overpotential (eta(50)) from 277 mV to 279 mV after a 20 h chronopotentiometry test. These findings suggest that trimetallic iron, nickel and cobalt sulfide, selenide, and especially sulfoselenide materials hold promise as high-performance, cost-effective, and durable electrocatalysts for sustainable OER reactions. This study provides a valuable approach for the development of efficient electrocatalytic materials, contributing to the advancement of renewable energy technologies.