Porous Hollow‐Structured LaNiO₃ Stabilized N,S‐Codoped Graphene as an Active Electrocatalyst for Oxygen Reduction Reaction

Abstract

A nanohybrid based on porous and hollow interior structured LaNiO stabilized nitrogen and sulfur codoped graphene (LaNiO /N,S-Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O -saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow-structured LaNiO spheres and heteroatom doped efficiency on graphene structure. In addition, N,S-Gr can meritoriously stabilize monodispersion of the LaNiO spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non-Pt catalysts for ORR in alkaline media.

Self‐Powered Water‐Splitting Devices by Core–Shell NiFe@N‐Graphite‐Based Zn–Air Batteries

“…Meanwhile, the limiting current density ( j L ) for Fe 0.5 Ni 0.5 @N‐GR electrocatalyst is about 4.05 mA cm −2 at the potential of 0.2 V (vs reversible hydrogen electrode (RHE)), which is comparable to that of Pt/C (5.02 mA cm −2 ). These experimental results demonstrate that Fe 0.5 Ni 0.5 @N‐GR is also the best ORR electrocatalyst among the samples that we have studied, where there are enriched active sites and synergistic coupling effects in N‐GR . To further gain insights into the ORR kinetics, RDE measurements at various rotating speeds for Fe 0.5 Ni 0.5 @N‐GR were performed.…”

Recent Advances in Novel Nanostructuring Methods of Perovskite Electrocatalysts for Energy‐Related Applications

“…In addition, hydrothermal synthesis helps in processing perovskite oxides with various morphologies such as nanocubes, nanorods, nanospheres, and yolk–shell nanostructures, other than just nanoparticles compared to the sol–gel process . More importantly, the hydrothermal method acts as one of the most attractive techniques for fabricating nanohybrid materials, for example, perovskite oxides composited with undoped graphene or heteroatom‐doped graphene . A typical hydrothermal process is illustrated taking the synthesis of a porous hollow‐structured LaNiO 3 ‐stabilized nitrogen and sulfur‐codoped graphene (LaNiO 3 /N,S‐Gr hybrid) for an example .…”

“…More importantly, the hydrothermal method acts as one of the most attractive techniques for fabricating nanohybrid materials, for example, perovskite oxides composited with undoped graphene or heteroatom‐doped graphene . A typical hydrothermal process is illustrated taking the synthesis of a porous hollow‐structured LaNiO 3 ‐stabilized nitrogen and sulfur‐codoped graphene (LaNiO 3 /N,S‐Gr hybrid) for an example . Graphene oxide (GO) synthesized from a modified Hummer's method and thiourea (as the N and S source) were sonicated and dispersed in deionized water, followed by mixing with an aqueous solution of metal precursors (lanthanum nitrate and nickel nitrate), glycine, and polyvinylpyrrolidone (PVP).…”

“…A schematic of the synthesis of LaNiO 3 /N,S‐Gr nanohybrid. Reproduced with permission . Copyright 2017, WILEY‐VCH.…”

Free-standing Three Dimensional Graphene Incorporated with Gold Nanoparticles as Novel Binder-free Electrochemical Sensor for Enhanced Glucose Detection

“…Among these nanomaterials, graphene (GR), a twodimensional monolayer of sp 2 -hybridized carbon atoms, has attracted enormous interest due to its extraordinary properties [1,2]. In particular, two and three dimensional (3D) metal-graphene hybrids have demonstrated to provide new advances in various fields, such as field-effect transistors, biological/ chemical sensors, energy applications, gas barrier, and transparent conductors [3][4][5][6]. Although many promising applications have been demonstrated, a huge challenge and need still remains for the efficient use of graphene's large specific surface area and extraordinary electrical, chemical, and mechanical properties.…”