Tuning surface electron transfer process by sulfur(S)-vacancies engineering is an efficient strategy to develop high-efficient catalysts for electroreduction N_(2) reaction(NRR). Herein, the distinct Sb_(2)S_(3) nanor...Tuning surface electron transfer process by sulfur(S)-vacancies engineering is an efficient strategy to develop high-efficient catalysts for electroreduction N_(2) reaction(NRR). Herein, the distinct Sb_(2)S_(3) nanorods with S-vacancies(Sv-Sb_(2)S_(3)) have been synthesized by a simple twostep method including hydrothermal and hydrogenation in H_(2)/Ar atmosphere, which shows improved performance for NRR with the NH_(3) yield rate of 10.85 μg h^(-1) mgcat^(-1) at-0.4 V vs. RHE, the faradaic efficiency(FE) of 3.75% at -0.3 V vs. RHE and excellent stability for 24 h, largely outperforming bulk Sb_(2)S_(3). X-ray photoelectron spectroscopy(XPS) and density function theory(DFT) calculations demonstrate that the abundant S-vacancies can create an electron-deficient environment and modulate the electron delocalization in Sv-Sb_(2)S_(3), which can not only facilitate the N_(2) molecule adsorption, but also activate the N≡N, resulting in the enhanced performance for NRR.展开更多
基金supported by Natural Science Foundation of China (NSFC no. 21673105)the Science and Technology Program of Gansu Province of China (Grant No.1717JR5RA194)。
文摘Tuning surface electron transfer process by sulfur(S)-vacancies engineering is an efficient strategy to develop high-efficient catalysts for electroreduction N_(2) reaction(NRR). Herein, the distinct Sb_(2)S_(3) nanorods with S-vacancies(Sv-Sb_(2)S_(3)) have been synthesized by a simple twostep method including hydrothermal and hydrogenation in H_(2)/Ar atmosphere, which shows improved performance for NRR with the NH_(3) yield rate of 10.85 μg h^(-1) mgcat^(-1) at-0.4 V vs. RHE, the faradaic efficiency(FE) of 3.75% at -0.3 V vs. RHE and excellent stability for 24 h, largely outperforming bulk Sb_(2)S_(3). X-ray photoelectron spectroscopy(XPS) and density function theory(DFT) calculations demonstrate that the abundant S-vacancies can create an electron-deficient environment and modulate the electron delocalization in Sv-Sb_(2)S_(3), which can not only facilitate the N_(2) molecule adsorption, but also activate the N≡N, resulting in the enhanced performance for NRR.
基金supported by the National Natural Science Foundation of China (21673105)the support received from NSF under the award numbers OIA-1539035 and CHE-1539035supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award No. DE-AC02-06CH11357
文摘析氧反应(OER)电催化剂的本征活性及稳定性主要取决于活性材料的表界面性能.本文采用两步水热法制备了一种新型核壳异质结构电催化剂(NF/NiSe@Fe_(2)O_(3)).该催化剂在1 mol L^(-1)的KOH介质中,电流密度为10或200 mA cm^(-2)时,析氧反应过电位分别低至220和282 mV,同时还具有较小的Tafel斜率(36.9 mV dec^(-1))及良好的长期稳定性(~230h).X射线光电子能谱和X射线吸收光谱表明,NF/NiSe@Fe_(2)O_(3)异质结构一方面具有高度羟基化的表面,同时由于在NiSe和Fe_(2)O_(3)的界面处形成Fe-Se键而具有较强的界面耦合作用.密度泛函理论计算进一步证实,Fe-Se键的形成导致了NiSe@Fe_(2)O_(3)异质结d带中心的移动并很好地优化了其电子结构,从而促进了析氧反应过程中含氧中间体的吸附及O_(2)的脱附,极大增强了催化剂的OER活性.另外,其独特的核壳结构及较强的界面耦合作用有效提升了催化剂的长期稳定性.该研究为界面键合效应对电催化剂OER性能的影响提供了一些基本认识.
