合理的设计策略以提高贵金属电催化剂在析氢反应(HER)中的利用率,对于简化HER的工艺流程,促进未来能源循环经济的发展至关重要.本文在约2.4 nm的Ru纳米颗粒上设计了大量的缺陷,使其在苛刻的酸性和碱性电解质中具有超高质量比反应活性....合理的设计策略以提高贵金属电催化剂在析氢反应(HER)中的利用率,对于简化HER的工艺流程,促进未来能源循环经济的发展至关重要.本文在约2.4 nm的Ru纳米颗粒上设计了大量的缺陷,使其在苛刻的酸性和碱性电解质中具有超高质量比反应活性.在过电势为100 m V时,所制备的缺陷富集型Ru基电催化剂DR-Ru表现出超高的HER翻转频率(碱性:16.4 s^(-1);酸性:20.6 s^(-1))和超低的过电势(碱性:η10=28.2 m V;酸性:η10=25.1 mV),明显优于其他Ru基电催化剂.此外,低配位的Ru活性位和表面部分晶格氧削弱了DR-Ru的Ru–H结合能,促进了酸性HER进行;同时有利于H2O分子分解,缓解了碱性HER过程中水分子的解离迟滞,导致其具有与酸性HER相当的高质量比活性.展开更多
The local structures and optical absorption characteristics of Fe doped TiO2 nanoparticles synthesized by the sol-gel method were characterized by X-ray diffraction (XRD), X-ray absorption fine structure spectrosco...The local structures and optical absorption characteristics of Fe doped TiO2 nanoparticles synthesized by the sol-gel method were characterized by X-ray diffraction (XRD), X-ray absorption fine structure spectroscopy (XAFS) and ultraviolet-visible absorption spectroscopy (UV-Vis). XRD patterns show that all Fe-doped TiO2 samples have the characteristic anatase structure. Accurate Fe and Ti K-edge EXAFS analysis further reveal that all Fe atoms replace Ti atoms in the anatase lattice. The analysis of UV-Vis data shows a red shift to the visible range. According to the above results, we claim that substitutional Fe atoms lead to the formation of structural defects and new intermediate energy levels appear, narrowing the band gap and extending the optical absorption edge towards the visible region.展开更多
基金supported by the National Natural Science Foundation of China (U1932212, 11875257, and U1932109)the Fundamental Research Funds for the Central Universities (WK2310000070)
文摘合理的设计策略以提高贵金属电催化剂在析氢反应(HER)中的利用率,对于简化HER的工艺流程,促进未来能源循环经济的发展至关重要.本文在约2.4 nm的Ru纳米颗粒上设计了大量的缺陷,使其在苛刻的酸性和碱性电解质中具有超高质量比反应活性.在过电势为100 m V时,所制备的缺陷富集型Ru基电催化剂DR-Ru表现出超高的HER翻转频率(碱性:16.4 s^(-1);酸性:20.6 s^(-1))和超低的过电势(碱性:η10=28.2 m V;酸性:η10=25.1 mV),明显优于其他Ru基电催化剂.此外,低配位的Ru活性位和表面部分晶格氧削弱了DR-Ru的Ru–H结合能,促进了酸性HER进行;同时有利于H2O分子分解,缓解了碱性HER过程中水分子的解离迟滞,导致其具有与酸性HER相当的高质量比活性.
基金Supported by National Basic Research Program of China(2012CB825801)Science Fund for Creative Research Groups of NSFC(11321503)+1 种基金National Natural Science Foundation of China(11321503,11179004)Guangdong Natural Science Foundation(S2011040003985)
文摘The local structures and optical absorption characteristics of Fe doped TiO2 nanoparticles synthesized by the sol-gel method were characterized by X-ray diffraction (XRD), X-ray absorption fine structure spectroscopy (XAFS) and ultraviolet-visible absorption spectroscopy (UV-Vis). XRD patterns show that all Fe-doped TiO2 samples have the characteristic anatase structure. Accurate Fe and Ti K-edge EXAFS analysis further reveal that all Fe atoms replace Ti atoms in the anatase lattice. The analysis of UV-Vis data shows a red shift to the visible range. According to the above results, we claim that substitutional Fe atoms lead to the formation of structural defects and new intermediate energy levels appear, narrowing the band gap and extending the optical absorption edge towards the visible region.