Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a signific...Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22275210)the Natural Science Foundation of Shandong Province(Grant No.ZR2024QB025,ZR2023ME155)the Taishan Scholar Project of Shandong Province(tsqn202306226)。
文摘Optimizing the energy barrier of 2H-to-1T phase transformation plays a crucial role in modulating the intrinsic electronic structure of MoS_(2)to achieve satisfactory water-splitting performance,but remains a significant challenge.Herein,we report a vacancy occupation-triggered phase transition strategy to fabricate a core-shell 1T phase nanorod structure,which is composed of S-vacancies decorated MoS_(2)as the core,and N,P co-doped carbons as the shell(1T-MoS_(2)@NPC).The co-insertion of N and P dopants into MoS_(2)can occupy partial S-vacancies,triggering a phase transformation from the semiconducting 2H phase to the conducting 1T phase with a reduced energy barrier.Profiting from the strong coupling effect between N,P dopants and S-vacancies,the as-made 1T-MoS_(2)@NPC exhibits excellent electrocatalytic activity for both HER(η_(10)=148 m V)and OER(η_(10)=232 mV)in alkaline solution.Meanwhile,a low cell voltage of 1.62 V is needed to drive a current density of 10mA cm^(-2)in 1.0 M KOH electrolyte.The theoretical calculation results reveal that the S-vacancies decorated C atoms in the meta-position relative to N,P atoms represent the most active HER and OER sites,which synergistically upshift the d band center and balance the rate-determining step,thus ensuring the simultaneous optimization of adsorption free energy and electronic structure.This vacancy-occupation-derived phase transformation strategy caused by non-metallic doping may provide valuable guidance for enhancing the performance of alkaline water electrolysis.
