Crystallinity Effect of NiFe LDH on the Growth of Pt Nanoparticles and Hydrogen Evolution Performance
27
Citation
28
Reference
10
Related Paper
Citation Trend
Abstract:
NiFe layered double hydroxides (LDHs) usually exhibit high water-dissociation ability in the alkaline media and also provide an ideal substrate for anchoring noble metals, such as platinum (Pt), due to the 2D microstructure. Appropriate regulation of the interaction between Pt and substrate could enhance the intrinsic activity of composite catalysts toward the hydrogen evolution reaction (HER) in the alkaline media. Herein, we electrodeposit Pt nanoparticles on amorphous NiFe LDH (Pt/NiFe-ED) or crystalline NiFe LDH (Pt/NiFe-HD) to regulate the interaction between Pt and NiFe LDH. Experimental results reveal that Pt nanoparticles on NiFe-ED are smaller than those on NiFe-HD and possess a narrower size distribution. Thus, Pt/NiFe-ED (300 μM) exhibits a much lower overpotential of 81 mV at 100 mA cm–2 than Pt/NiFe-HD. In contrast, Pt/NiFe-HD exhibits a higher intrinsic activity than Pt/NiFe-ED, which could be caused by the easily elongated Pt–O bond. These findings provide new opportunities to understand the relationship between activity and crystallinity of substrates in the composite electrocatalyst.Keywords:
Overpotential
Noble metal
Relationships developed earlier (1) for the dependence of the rate of appearance and propagation of dendrites on the properties of the system and overpotential, have been used to develop a quantitative theory of induction period and critical overpotential of dendritic growth. It has been shown that the thermodynamic concept of critical overpotential is applicable to metals of high exchange current density only. The limitations in the appearance of dendrites in metals of low exchange current density are of kinetic character and can be represented by a kinetically defined critical overpotential. The theory has been verified experimentally by following the yield of dendritic deposit of zinc from alkaline zincate solutions as a function of concentration of depositing ions, of overpotential, and of time of deposition.
Overpotential
Cite
Citations (40)
The structure of cobalt formed by electrodeposition and the influence of the pH of the plating solution and the cathode potential was studied by potentiodynamic measurements and X-ray diffraction. It was found that the level of overpotential significantly affects the structure of the formed cobalt. When electrodeposition is performed far from equilibrium conditions, i.e., at a high overpotential, face-centered cubic (fcc) cobalt is deposited while at low overpotential hexagonal close packed Co is formed with a lower rate of hydrogen evolution. A higher overpotential is needed in a neutral compared to acidic solution in order to enhance the evolution of hydrogen that is required for the formation of fcc cobalt. © 2002 The Electrochemical Society. All rights reserved.
Overpotential
Cite
Citations (60)
Oxygen evolution reaction (OER) involves multiple electron-transfer processes, resulting in a high activation barrier. Developing catalysts with low overpotential and high intrinsic activity toward OER is critical but challenging. Here we report a major advancement in decreasing the overpotential for oxygen evolution reaction. Ni foam-supported Fe-doped β-Ni(OH)2 nanosheets achieve an overpotential of 219 mV at the geometric current density of 10 mA cm–2. To our knowledge, this is the best value reported for Ni- or Fe hydroxide-based OER catalysts. In addition, the catalyst yields a current density of 6.25 mA cm–2 at the overpotential of 300 mV when it is normalized to the electrochemical surface area of the catalyst. This intrinsic catalytic activity is also better than the values reported for most state-of-the-art OER catalysts at the same overpotential.
Overpotential
Oxygen evolution
Cite
Citations (271)
The different thickness of HER film electrodes prepared by DC magnetron sputtering device,their overpotential attained at room temperature,1mol/L KOH is related with thickness of the film,the overpotential decreases with increasing of the thickness,although the decreasing degree of different material is varying.All these show that the HER reaction is not happened only on the surface of electrode,the M-H is formed inside the film electrode,and it is related with the characteristic of M-H,so thickness of the film affects the overpotential.
Overpotential
Cite
Citations (0)
Abstract The front cover artwork is provided by the group of Prof. Xiaoming Sun and Prof. Pengbo Wan at Beijing University of Chemical Technology (PR China). The image shows a Ni–Mo electrocatalyst for the hydrogen evolution reaction (HER). It is revealed that the performance of the fabricated 3D Ni–Mo electrocatalyst with negligible overpotential, high current density, ultrahigh activity, and durable stability for alkaline HER, challenges that of Pt catalysts. Read the full text of the article at 10.1002/celc.201402089 .
Overpotential
Nanoporous
Cite
Citations (4)
Overpotential
Copper sulfide
Cite
Citations (5)
In the search for nonprecious metal catalysts for the hydrogen evolution reaction (HER), transition metal dichalcogenides (TMDCs) have been proposed as promising candidates. Here, we present a facile method for significantly decreasing the overpotential required for catalyzing the HER with colloidally synthesized WSe2. Solution phase deposition of 2H WSe2 nanoflowers (NFs) onto carbon fiber electrodes results in low catalytic activity in 0.5 M H2SO4 with an overpotential at −10 mA/cm2 of greater than 600 mV. However, two postdeposition electrode processing steps significantly reduce the overpotential. First, a room-temperature treatment of the prepared electrodes with a dilute solution of the alkylating agent Meerwein's salt ([Et3O][BF4]) results in a reduction in overpotential by approximately 130 mV at −10 mA/cm2. Second, we observe a decrease in overpotential of approximately 200–300 mV when the TMDC electrode is exposed to H+, Li+, Na+, or K+ ions under a reducing potential. The combined effect of ligand removal and electrochemical activation results in an improvement in overpotential by as much as 400 mV. Notably, the Li+ activated WSe2 NF deposited carbon fiber electrode requires an overpotential of only 243 mV to generate a current density of −10 mA/cm2. Measurement of changes in the material work function and charge transfer resistance ultimately provide rationale for the catalytic improvement.
Overpotential
Cite
Citations (72)
Negligible overpotential for HER: The front cover artwork was chosen to represent a 3D Ni–Mo electrocatalyst with negligible overpotential for the alkaline hydrogen evolution reaction (HER). The 3D nanoporous Ni–Mo electrocatalyst was fabricated and investigated for alkaline HER. On page 1138, Prof. P. B. Wan et al. show how they synthesized the electrocatalyst with well-controlled composition, desired dimensions, and nanoporosity to exhibit improved HER performance with low overpotential, high current density, ultrahigh activity, and durable stability, challenging that of Pt/C catalyst. (DOI: 10.1002/celc.201402089).
Overpotential
Nanoporous
Cite
Citations (4)
Overpotential
Layered double hydroxides
Cite
Citations (16)
The promise and challenge of electrochemical mitigation of CO2 calls for innovations on both catalyst and reactor levels. In this work, enabled by our high-performance and earth-abundant CO2 electroreduction catalyst materials, we developed alkaline microflow electrolytic cells for energy-efficient, selective, fast, and durable CO2 conversion to CO and HCOO–. With a cobalt phthalocyanine-based cathode catalyst, the CO-selective cell starts to operate at a 0.26 V overpotential and reaches a Faradaic efficiency of 94% and a partial current density of 31 mA/cm2 at a 0.56 V overpotential. With a SnO2-based cathode catalyst, the HCOO–-selective cell starts to operate at a 0.76 V overpotential and reaches a Faradaic efficiency of 82% and a partial current density of 113 mA/cm2 at a 1.36 V overpotential. In contrast to previous studies, we found that the overpotential reduction from using the alkaline electrolyte is mostly contributed by a pH gradient near the cathode surface.
Overpotential
Noble metal
Cite
Citations (102)