Morphology controlled synthesis of cobalt diselenide nanorods for highly efficient hydrogen evolution in alkaline and acidic media

Abstract

The development of electrochemical water-splitting electrocatalysts that are stable, highly efficient, and affordable is essential to future energy supplements. In this article, we developed a facile synthesis process based on self-templating CoSe2 nanorod fabrication on carbon cloth (CoSe2/CC) that can act as an effective electrocatalyst for the hydrogen evaluation reaction (HER) in both alkaline and acidic electrolytes. CoSe2/CC is a binder-free promising candidate because of its suitable electronic configuration for electrocatalytic water splitting. When compared to bare CoSe2, the CoSe2/CC catalyst performs dramatically better in terms of HER performance and kinetics: the Tafel slopes of CoSe2/CC are significantly reduced from 83 mV dec−1 to 38 mV dec−1 with a lower overpotential of 98–52 mV in 1.0 M KOH and 0.5 M H2SO4 electrolytes, respectively to attain a current density of 10 mA cm2. Moreover, CoSe2/CC nanorods show excellent stability up to 1000 cycles in both alkaline and acidic media. The time-dependent voltage (V-t) chronopotentiometry of CoSe2/CC depicts its excellent long-term durability of 12 h in KOH and H2SO4. This research could lead to the development of a comprehensive methodology for the rational design and fabrication of other transition-metal selenide nano-structured materials to serve as efficient HER electrocatalysts.