In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type electrode alloys, Mg in the alloy was partially substituted by La, and the nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 ...In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type electrode alloys, Mg in the alloy was partially substituted by La, and the nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 (x-=0, 2) alloys were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical hydrogen storage properties of the experimental alloys were tested. The results show that no amorphous phase is detected in the as-spun Mg20Ni10 alloy, but the as-spun Mg18La2Ni10 alloy holds a major amorphous phase. As La content increases from 0 to 2, the maximum discharge capacity of the as-spun (20 m/s) alloys rises from 96.5 to 387.1 mA.h/g, and the capacity retaining rate (S20) at the 20th cycle grows from 31.3% to 71.7%. Melt-spinning engenders an impactful effect on the electrochemical hydrogen storage performances of the alloys. With the increase in the spinning rate from 0 to 30 m/s, the maximum discharge capacity increases from 30.3 to 135.5 mA.h/g for the Mg20Ni10 alloy, and from 197.2 to 406.5 mA-h/g for the Mg18La2Ni10 alloy. The capacity retaining rate (S20) of the Mg2oNi10 alloy at the 20th cycle slightly falls from 36.7% to 27.1%, but it markedly mounts up from 37.3% to 78.3% for the Mg18La2Ni10 alloy.展开更多
An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer....An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer.The photocurrent of the oxide‐layer‐containing photoanode was2.52mA/cm2at1.23V versus the reversible hydrogen electrode,in potassium phosphate buffer,(0.5mol/L,pH=7.0).The amorphous ferric oxide layer on the photoanode contained low‐valence‐state iron species(FeII),which enabled efficient hole extraction and transfer.展开更多
Oxygen evolution reaction(OER), as the primary anodic reaction, plays a critical role in many electrochemical energy conversion processes. As the state-of-the-art OER catalysts, iridium-based materials are largely hin...Oxygen evolution reaction(OER), as the primary anodic reaction, plays a critical role in many electrochemical energy conversion processes. As the state-of-the-art OER catalysts, iridium-based materials are largely hindered from practical applications mainly due to the extreme scarcity of iridium. Here we demonstrate the successful fabrication of boron-doped amorphous iridium oxide(IrO_(x)-B) via a facile boric acid-assisted method, which realizes an ultrahigh OER mass activity of 2779 A g^(-1)Irat 300 mV overpotential, representing one of the best acidic OER catalysts reported so far.It is found that boric acid can not only facilitate the exposure of Ir, but also dope the amorphous IrOxwith a form of metaborate, which could further modify the electronic and local ligand structure of Ir for the improved intrinsic activity. Interestingly, the reported strategy is universal that can be applied to improve other metal oxide OER catalysts, highlighting a versatile strategy for creating high-performance electrocatalysts with ultrahigh mass activity for OER and beyond.展开更多
基金Projects(50871050, 50961009) supported by the National Natural Science Foundation of ChinaProject(2010ZD05) supported by the Natural Science Foundation of Inner Mongolia, ChinaProject(NJzy08071) supported by the Higher Education Science Research Project of Inner Mongolia, China
文摘In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type electrode alloys, Mg in the alloy was partially substituted by La, and the nanocrystalline and amorphous Mg2Ni-type Mg20-xLaxNi10 (x-=0, 2) alloys were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical hydrogen storage properties of the experimental alloys were tested. The results show that no amorphous phase is detected in the as-spun Mg20Ni10 alloy, but the as-spun Mg18La2Ni10 alloy holds a major amorphous phase. As La content increases from 0 to 2, the maximum discharge capacity of the as-spun (20 m/s) alloys rises from 96.5 to 387.1 mA.h/g, and the capacity retaining rate (S20) at the 20th cycle grows from 31.3% to 71.7%. Melt-spinning engenders an impactful effect on the electrochemical hydrogen storage performances of the alloys. With the increase in the spinning rate from 0 to 30 m/s, the maximum discharge capacity increases from 30.3 to 135.5 mA.h/g for the Mg20Ni10 alloy, and from 197.2 to 406.5 mA-h/g for the Mg18La2Ni10 alloy. The capacity retaining rate (S20) of the Mg2oNi10 alloy at the 20th cycle slightly falls from 36.7% to 27.1%, but it markedly mounts up from 37.3% to 78.3% for the Mg18La2Ni10 alloy.
基金supported by the National Natural Science Foundation of China(21373083,21573068)Program of Shanghai Subject Chief Scientist(15XD1501300)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education MinistryScience Technology Commission of Shanghai Municipality(14JC1490900)~~
文摘An amorphous ferric oxide layer was prepared on a bismuth vanadate photoanode.This resulted in improved charge carrier separation and surface catalytic performance compared with the photoanode without the oxide layer.The photocurrent of the oxide‐layer‐containing photoanode was2.52mA/cm2at1.23V versus the reversible hydrogen electrode,in potassium phosphate buffer,(0.5mol/L,pH=7.0).The amorphous ferric oxide layer on the photoanode contained low‐valence‐state iron species(FeII),which enabled efficient hole extraction and transfer.
基金financially supported by the Ministry of Science and Technology (2017YFA0208200 and 2016YFA0204100)the National Natural Science Foundation of China (22025108 and 51802206)+3 种基金the Natural Science Foundation of Jiangsu Province (BK20180846)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Project of Scientific and Technologic Infrastructure of Suzhou (SZS201905)the Start-up Supports from Xiamen University。
文摘Oxygen evolution reaction(OER), as the primary anodic reaction, plays a critical role in many electrochemical energy conversion processes. As the state-of-the-art OER catalysts, iridium-based materials are largely hindered from practical applications mainly due to the extreme scarcity of iridium. Here we demonstrate the successful fabrication of boron-doped amorphous iridium oxide(IrO_(x)-B) via a facile boric acid-assisted method, which realizes an ultrahigh OER mass activity of 2779 A g^(-1)Irat 300 mV overpotential, representing one of the best acidic OER catalysts reported so far.It is found that boric acid can not only facilitate the exposure of Ir, but also dope the amorphous IrOxwith a form of metaborate, which could further modify the electronic and local ligand structure of Ir for the improved intrinsic activity. Interestingly, the reported strategy is universal that can be applied to improve other metal oxide OER catalysts, highlighting a versatile strategy for creating high-performance electrocatalysts with ultrahigh mass activity for OER and beyond.