The rational design and synthesis of noble-metal-free electrocatalysts for water splitting is always important for the future hydrogen economy.Therefore,it is necessary to design an effective transition metal sulfide ...The rational design and synthesis of noble-metal-free electrocatalysts for water splitting is always important for the future hydrogen economy.Therefore,it is necessary to design an effective transition metal sulfide down to a molecular level.In this work,a multi-level spatial confinement strategy was developed to fabricate Co-promoted 1T-MoS_(2)(1T-Co-MoS_(2))by employing Evans-Showell-type polyoxometalates(POMs)[Co_(2)Mo_(10)O_(38)H_(4)]as molecular precursor.Highly dispersed 1T-Co-MoS_(2) nanoclusters with few layers(1-3 layers)and ultrasmall size(<5 nm)were synthesized within the hollow mesoporous carbon sphere(HMCS)by in situ vapor phase sulfurization.During the preparation,coordination bonds,organic cations and mesopores provide a triple-confinement environment to limit the growth of 1T-Co-MoS_(2) from the atomic level,molecular level to mesoscopic scale.The obtained 1T-Co-MoS_(2)@HMCS exhibits remarkable electrocatalytic activity and excellent long-term durability for hydrogen evolution reaction(HER),with overpotentials of 220 and 245 mV to achieve the current density of 200 mA cm^(-2) in 1 M KOH and 0.5 M H_(2)SO_(4),respectively.The corresponding theoretical calculations indicate that Co-S edge sites are the most active sites of 1T-Co-MoS_(2) for HER,reflecting the major significance of Co doping.The superior HER performance could be attributed to the high intrinsic activity from Co-doped 1T-MoS_(2) sites,abundant exposed active sites from ultra-dispersed nanosheets,and enhanced charge and mass transfer within the HMCS substrate.This work provides a novel design concept via hierarchical multiple-level confinement for the synthesis of high-quality 1T-Co-MoS_(2) and achieves outstanding performance in electrocatalytic HER.展开更多
基金supported by the National Natural Science Foundation of China(21878336,21805308)the Shandong Provincial Natural Science Foundation,China(ZR2018MB035)+1 种基金the Key Research and Development Project of Shandong Province(2019GSF109075)the Fundamental Research Funds for the Central Universities(20CX02213A),and the China University of Petroleum,Huadong(YCX2021153).
文摘The rational design and synthesis of noble-metal-free electrocatalysts for water splitting is always important for the future hydrogen economy.Therefore,it is necessary to design an effective transition metal sulfide down to a molecular level.In this work,a multi-level spatial confinement strategy was developed to fabricate Co-promoted 1T-MoS_(2)(1T-Co-MoS_(2))by employing Evans-Showell-type polyoxometalates(POMs)[Co_(2)Mo_(10)O_(38)H_(4)]as molecular precursor.Highly dispersed 1T-Co-MoS_(2) nanoclusters with few layers(1-3 layers)and ultrasmall size(<5 nm)were synthesized within the hollow mesoporous carbon sphere(HMCS)by in situ vapor phase sulfurization.During the preparation,coordination bonds,organic cations and mesopores provide a triple-confinement environment to limit the growth of 1T-Co-MoS_(2) from the atomic level,molecular level to mesoscopic scale.The obtained 1T-Co-MoS_(2)@HMCS exhibits remarkable electrocatalytic activity and excellent long-term durability for hydrogen evolution reaction(HER),with overpotentials of 220 and 245 mV to achieve the current density of 200 mA cm^(-2) in 1 M KOH and 0.5 M H_(2)SO_(4),respectively.The corresponding theoretical calculations indicate that Co-S edge sites are the most active sites of 1T-Co-MoS_(2) for HER,reflecting the major significance of Co doping.The superior HER performance could be attributed to the high intrinsic activity from Co-doped 1T-MoS_(2) sites,abundant exposed active sites from ultra-dispersed nanosheets,and enhanced charge and mass transfer within the HMCS substrate.This work provides a novel design concept via hierarchical multiple-level confinement for the synthesis of high-quality 1T-Co-MoS_(2) and achieves outstanding performance in electrocatalytic HER.
