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Mg Doped Perovskite LaNiO <sub/>3</sub> Nanofibers as an Efficient Bifunctional Catalyst for Rechargeable Zinc–Air Batteries
摘要： Rational design of efficient and durable bifunctional catalysts toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is important for rechargeable zinc-air batteries. Herein, Mg doped perovskite LaNiO3 (LNO) nanofibers (LNMO NFs) were prepared by a facile electrospinning method combined with subsequent calcination. LNMO NFs show a more positive half-wave potential of 0.69V and a lower overpotential of 0.45 V at a current density of 10 mA cm-2 than those of the pristine LNO NFs. As an air electrode for zinc-air battery, the cell with LaNi0.85Mg0.15O3 NFs catalyst is able to deliver a high specific capacity of 809.9 mAh g-1 at a current density of 5 mA cm-2. It also shows an excellent cycling stability over 110 h at a current density of 10 mA cm?2. DFT calculation results demonstrate that the LNMO surface binds oxygen stronger than LNO, which contributes to enhanced OER activity as observed in our experiments. The results indicate that LNMO NFs is an efficient and durable bifunctional catalyst for zinc-air batteries.
关键词： bi-functional catalyst,Mg doped LaNiO3 nanofibers,electrospinning,density functional theory calculation,zinc-air batteries
更新于2025-11-14 17:04:02
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Effects of LNO buffer layers on electrical properties of BFO-PT thin films on stainless steel substrates
摘要： Ferroelectric 0.7BiFeO3-0.3PbTiO3 (BFO-PT) thin films were deposited on LaNiO3 (LNO) coated stainless steel (SS) substrates by the sol-gel method. XRD results indicate that both LNO and BFO-PT thin films have the perovskite structure and the film crystallinity is improved with increasing the LNO thickness. The dielectric loss of BFO-PT thin films is reduced significantly with addition of LNO buffer layers, achieving about 4 % at the frequency of 1 kHz, much lower than that of > 20 % for BFO-PT thin films directly deposited on SS substrates. BFO-PT thin films reveal the strong ferroelectricity with remnant polarization (Pr) of about 35 m C/cm2 for LNO of 390 nm. Moreover, addition of LNO buffer layers mitigates the polarization deterioration after the 1.33×108 switching cycles resulting in the improved anti-fatigue properties of BFO-PT thin films. Our results indicate that BFO-PT/LNO multilayer thin films on SS substrates maintain excellent dielectric and ferroelectric properties.
关键词： 0.7BiFeO3-0.3PbTiO3 thin films,Stainless steel substrates,LaNiO3
更新于2025-09-23 15:22:29
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A laser-ARPES study of LaNiO <sub/>3</sub> thin films grown by sputter deposition
摘要： Thin films of the correlated transition-metal oxide LaNiO3 undergo a metal–insulator transition when their thickness is reduced to a few unit cells. Here, we use angle-resolved photoemission spectroscopy to study the evolution of the electronic structure across this transition in a series of epitaxial LaNiO3 films of thicknesses ranging from 19 u.c. to 2 u.c. grown in situ by RF magnetron sputtering. Our data show a strong reduction in the electronic mean free path as the thickness is reduced below 5 u.c. This prevents the system from becoming electronically two-dimensional, as confirmed by the largely unchanged Fermi surface seen in our experiments. In the insulating state, we observe a strong suppression of the coherent quasiparticle peak, but no clear gap. These features resemble previous observations of the insulating state of NdNiO3.
关键词： LaNiO3,angle-resolved photoemission spectroscopy,electronic structure,metal–insulator transition,thin films
更新于2025-09-23 15:21:01
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Effects of Surface Termination and Layer Thickness on Electronic Structures of LaNiO <sub/>3</sub> Thin Films
摘要： We investigate the e?ects of surface termination and layer thickness on the electronic structures of LaNiO3 thin ?lms on SrTiO3 substrate using ?rst-principles density-functional theory calculations. The NiO2-terminated ?lm with one unit cell thickness shows a pseudogap at the Fermi level owing to the negative charge transfer energy, whereas the 1.5-unit-cell-thick LaO-terminated ?lm exhibits an insulating gap of 1.0 eV as a result of the large exchange splitting. The metallic state is quickly restored for thicker ?lms with either NiO2 or LaO termination, resembling that in bulk nickelate. Our results indicate the strong dependence of the electronic properties on layer thickness and provide insightful information into the metal–insulator transition in LaNiO3 thin ?lms.
关键词： surface termination,electronic structures,layer thickness,LaNiO3 thin films,metal–insulator transition
更新于2025-09-04 15:30:14