The rational design of double active sites system is vital for constructing high-efficiency iron sulfides electrocatalysts towards hydrogen evolution reaction(HER) in alkaline media. However, it remains a challenge to...The rational design of double active sites system is vital for constructing high-efficiency iron sulfides electrocatalysts towards hydrogen evolution reaction(HER) in alkaline media. However, it remains a challenge to controllably create the high-density interface of double sites for optimal synergistic effect.Herein, we reported a simple chemical oxidation-induced surface reconfiguration strategy to obtain the interface-rich Fe_(3)O_(4)-FeS nanoarray supported on iron foam(Fe_(3)O_(4)-FeS/IF) using FeS nanosheets as precursors. The abundant Fe_(3)O_(4)-FeS interfaces could improve the dispersion of active sites and facilitate the electron transfer, leading to enhanced hydrogen evolution efficiency. And meanwhile, by altering the oxidation temperature, the content of S and O could be effectively controlled, further achieving the ratio optimization of Fe_(3)O_(4)to FeS. Synchrotron-based X-ray absorption near-edge structure, X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy consistently confirm the changes of electronic structure and d-band center of Fe_(3)O_(4)-FeS after chemical oxidation. Consequently, Fe_(3)O_(4)-FeS/IF exhibits excellent alkaline HER activity with a low overpotential of 120.8 mV to reach 20 mA cm^(-2),and remains stable ranging from 10, 20 to 50 mA cm^(-2) for each 20 h, respectively. Therefore, the facile and controllable chemical oxidation may be an effective strategy for designing high-density interfaces of transition metal-based sulfides towards alkaline HER.展开更多
基金financially supported by National Natural Science Foundation of China (52174283)the Qingdao Science and Technology Benefiting People Special Project (20-3-4-8-nsh)+1 种基金the Fundamental Research Funds for the Central Universities(20CX02212A)the Development Fund of State Key Laboratory of Heavy Oil Processing and the Postgraduate Innovation Project of China University of Petroleum (YCX2020042)。
文摘The rational design of double active sites system is vital for constructing high-efficiency iron sulfides electrocatalysts towards hydrogen evolution reaction(HER) in alkaline media. However, it remains a challenge to controllably create the high-density interface of double sites for optimal synergistic effect.Herein, we reported a simple chemical oxidation-induced surface reconfiguration strategy to obtain the interface-rich Fe_(3)O_(4)-FeS nanoarray supported on iron foam(Fe_(3)O_(4)-FeS/IF) using FeS nanosheets as precursors. The abundant Fe_(3)O_(4)-FeS interfaces could improve the dispersion of active sites and facilitate the electron transfer, leading to enhanced hydrogen evolution efficiency. And meanwhile, by altering the oxidation temperature, the content of S and O could be effectively controlled, further achieving the ratio optimization of Fe_(3)O_(4)to FeS. Synchrotron-based X-ray absorption near-edge structure, X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy consistently confirm the changes of electronic structure and d-band center of Fe_(3)O_(4)-FeS after chemical oxidation. Consequently, Fe_(3)O_(4)-FeS/IF exhibits excellent alkaline HER activity with a low overpotential of 120.8 mV to reach 20 mA cm^(-2),and remains stable ranging from 10, 20 to 50 mA cm^(-2) for each 20 h, respectively. Therefore, the facile and controllable chemical oxidation may be an effective strategy for designing high-density interfaces of transition metal-based sulfides towards alkaline HER.
