Pentlandite cobalt sulfide (Co_(9)S_(8)) has gained significant attention as a water-splitting electrocatalyst on account of its intrinsic metallic conductivity and active sites.However,the robust sulfur-hydrogen (S-H...Pentlandite cobalt sulfide (Co_(9)S_(8)) has gained significant attention as a water-splitting electrocatalyst on account of its intrinsic metallic conductivity and active sites.However,the robust sulfur-hydrogen (S-Hads) bonds formed on Co_(9)S_(8)’s surface significantly impede the atomic hydrogen desorption and suppress the overall HER performance.Herein,nitrogen and phosphorous anion co-doped Co_(9)S_(8) (N,P-Co_(9)S_(8)) was in situ synthesized on cobalt foam,and the material can serve as an efficient precious metal-free bifunctional catalyst for electrochemical water splitting in basic media.Remarkably,N,P-Co_(9)S_(8) exhibits much better HER activity than the pristine Co_(9)S_(8) with smaller overpotentials of 80 and 189 mV to deliver current densities of 10 and 100 mA cm^(-2),respectively,in 1.0 M KOH solution,as well as a lower Tafel slope of 104 mV dec-1.The remarkable HER performance is mainly attributed to the electronic structure and surface wettability of Co_(9)S_(8) regulated by anion doping.The N and P anion co-doping can synergistically increase the water dissociation,optimize atomic hydrogen desorption,and accelerate mass transfer,giving rise to the improvement of HER performance.Moreover,N,P-Co_(9)S_(8) is found to bifunctionally electrolyze the OER in alkaline electrolytes with outstanding activity and super-catalytic stability.The assembled water electrolyzer using N,P-Co_(9)S_(8) as both the anode and cathode only needs small cell voltages of 1.90 and 1.74 V to drive a current density of 100 mA cm^(-2) at 25 and 65℃℃,respectively.展开更多
基金financial support from the National Natural Science Foundation of Guangdong Province(2022A1515010211 and 207078903043).
文摘Pentlandite cobalt sulfide (Co_(9)S_(8)) has gained significant attention as a water-splitting electrocatalyst on account of its intrinsic metallic conductivity and active sites.However,the robust sulfur-hydrogen (S-Hads) bonds formed on Co_(9)S_(8)’s surface significantly impede the atomic hydrogen desorption and suppress the overall HER performance.Herein,nitrogen and phosphorous anion co-doped Co_(9)S_(8) (N,P-Co_(9)S_(8)) was in situ synthesized on cobalt foam,and the material can serve as an efficient precious metal-free bifunctional catalyst for electrochemical water splitting in basic media.Remarkably,N,P-Co_(9)S_(8) exhibits much better HER activity than the pristine Co_(9)S_(8) with smaller overpotentials of 80 and 189 mV to deliver current densities of 10 and 100 mA cm^(-2),respectively,in 1.0 M KOH solution,as well as a lower Tafel slope of 104 mV dec-1.The remarkable HER performance is mainly attributed to the electronic structure and surface wettability of Co_(9)S_(8) regulated by anion doping.The N and P anion co-doping can synergistically increase the water dissociation,optimize atomic hydrogen desorption,and accelerate mass transfer,giving rise to the improvement of HER performance.Moreover,N,P-Co_(9)S_(8) is found to bifunctionally electrolyze the OER in alkaline electrolytes with outstanding activity and super-catalytic stability.The assembled water electrolyzer using N,P-Co_(9)S_(8) as both the anode and cathode only needs small cell voltages of 1.90 and 1.74 V to drive a current density of 100 mA cm^(-2) at 25 and 65℃℃,respectively.
