CoOx-NCNT-Supported NiFe-Selenide Nanosheets as an Efficient Bifunctional Electrocatalyst for Water Splitting

Abstract

Efficient and stable electrocatalysts play a fundamental role in advancing the kinetics of water splitting for clean hydrogen production. Transitionmetal selenides have been explored as viable candidates for water splitting due to their high abundance and remarkable activities. In this work, we present a novel and versatile strategy to synthesize a high-performance electrocatalyst (NiFeSe@CoO x -NCNTs) that exhibits excellent electrocatalytic activity for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). NiFeSe@ CoO x -NCNTs have been fabricated by the selenization of NiFe-LDH/CoOx-NCNTs which were synthesized by adopting a hydrothermal approach. The resulting material demonstrates an OER overpotential (η) of only 240 mV at 20 mA/cm 2 , accompanied by a small Tafel value of 59.2 mV/dec. The catalyst also exhibits outstanding electrocatalytic activity toward HER with an η of 145 mV at 20 mA/cm 2 . The better HER kinetics on the surface of NiFeSe@CoO x -NCNTs is further supported by a small Tafel slope of ∼169 mV/dec. The small charge transfer resistance (R ct ) experienced by NiFeSe@CoO x -NCNTs during both the OER and HER is an indication of the fast movement of active species, which contributes to the enhanced electrocatalytic activity. The high stability of NiFeSe@CoO x -NCNTs for a period of 15 h makes the electrocatalyst an appealing candidate for energy conversion systems.

Advances in zeolitic-imidazolate-framework-based catalysts for photo-/electrocatalytic water splitting, CO2 reduction and N2 reduction applications

“…8b). 143 NiFe-LDH promoted the formation of layered structures, ZIF-12-derived NCNT provided nitrogen doping, and CoO x nanoparticles solved the inherent carbon corrosion issue during electrocatalytic OER and HER, resulting in an excellent electrocatalytic total water splitting activity.…”