Self-templating construction of Fe, F dual-doped CoS2 hollow nanospheres for highly efficient oxygen evolution reaction

초록

Due to the serious energy crisis and environmental problems, developing clean and highly efficient energy sources has been received extensive attention. Electrochemical water splitting, which can produce ultrapure hydrogen gases, is consisted of anodic oxygen evolution reaction and cathodic hydrogen evolution reaction. Notably, the complicated reaction mechanism of OER with four-electron transfer process causes significant overpotential, thereby resulting in poor electrochemical efficiency for overall water electrolysis. Until now, noble metal-based oxide materials (IrO2 and RuO2) were employed as state-of-the-art electrocatalyst owing to the superior OER activity. However, their high cost and unsatisfactory long-term durability hinder the large-scale application of water electrolysis. Therefore, a lot of researchers have devoted to developing non-noble metal-based electrocatalysts with low cost, enhanced OER activity, and electrochemical durability. Herein, we proposed facile and readily scalable synthetic method of hollow-structured Fe, F dual-doped CoS2 nanosphere (Fe-CoS2-F) using Co-glycerate nanosphere as a self-sacrificial template. The Co-glycerate solid sphere was converted into hollow-structured bimetallic CoFe-PBA via simple anion exchange process at room temperature. Subsequently, simultaneous sulfidation and fluorination process was conducted by heat treatment under Ar atmosphere, thereby resulting in hollow-structured Fe-CoS2-F. As a result, the Fe-CoS2-F electrocatalyst exhibited remarkable electrocatalytic performance toward OER with small overpotential (298 mV at a current density of 10 mA cm?2), low Tafel slope (46 mV dec?1), and robust long-term durability (over 100 h) in alkaline electrolyte. Therefore, this study would provide new insight into the development of noble metal-free materials for diverse energy storage and conversion applications.