scholarly journals Electrocatalytic Properties of Pulse-Reverse Electrodeposited Nickel Phosphide for Hydrogen Evolution Reaction

2021 ◽  
Vol 9 ◽  
Author(s):  
Woohyeon Jo ◽  
Dasol Jeong ◽  
Jaebum Jeong ◽  
Taegeon Kim ◽  
Seungyeon Han ◽  
...  

Nickel phosphide (Ni-P) films as a catalytic cathode for the hydrogen evolution reaction (HER) of a water splitting were fabricated by a pulse-reverse electrodeposition technique. The electrochemical behaviors for the electrodeposition of Ni-P were investigated by the characterization of peaks in a cyclic voltammogram. The composition of the electrodeposited Ni-P alloys was controlled by adjusting duty cycles of the pulse-reverse electrodeposition. The HER electrocatalytic properties of the Ni-P electrodeposits with an amorphous phase as a function of phosphorous contents existing in Ni-P were electrochemically characterized by the analysis of overpotentials, Tafel slopes, and electrochemical impedance spectrometry. Additionally, the elemental Ni-embedded crystalline Ni3P was prepared by an annealing process with the amorphous Ni69P31 electrodeposit with high contents of phosphorus. The crystalline structure with Ni inclusions in the matrix of Ni3P was formed by the precipitation of excess Ni. The electrocatalytic properties of crystalline Ni3P with elemental Ni inclusions were also investigated by electrochemical characterization.

2021 ◽  
Vol 9 (5) ◽  
pp. 2754-2763
Author(s):  
Kenya Kani ◽  
Hyunsoo Lim ◽  
Andrew E. Whitten ◽  
Kathleen Wood ◽  
Anya J. E. Yago ◽  
...  

The mesoporous RhNi alloy films are synthesized by controlling the concentration of Rh precursor, applied potentials, and pH via the electrochemical co-deposition method with self-assembled polymeric micelles templates for enhancing electrocatalytic properties.


2008 ◽  
Vol 44 (12) ◽  
pp. 1350-1358 ◽  
Author(s):  
V. V. Kuznetsov ◽  
A. A. Kalinkina ◽  
T. V. Pshenichkina ◽  
V. V. Balabaev

2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.


Metals ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 359 ◽  
Author(s):  
Fan Yang ◽  
Ning Kang ◽  
Jiayun Yan ◽  
Xiuli Wang ◽  
Jun He ◽  
...  

2019 ◽  
Vol 10 ◽  
pp. 62-70 ◽  
Author(s):  
Yong Li ◽  
Peng Yang ◽  
Bin Wang ◽  
Zhongqing Liu

Bimetallic phosphides have been attracting increasing attention due to their synergistic effect for improving the hydrogen evolution reaction as compared to monometallic phosphides. In this work, NiCoP modified hybrid electrodes were fabricated by a one-step electrodeposition process with TiO2 nanotube arrays (TNAs) as a carrier. X-ray diffraction, transmission electron microscopy, UV–vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy and scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy were used to characterize the physiochemical properties of the samples. The electrochemical performance was investigated by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. We show that after incorporating Co into Ni–P, the resulting Ni x Co y P/TNAs present enhanced electrocatalytic activity due to the improved electron transfer and increased electrochemically active surface area (ECSA). In 0.5 mol L−1 H2SO4 electrolyte, the Ni x Co y P/TNAs (x = 3.84, y = 0.78) demonstrated an ECSA value of 52.1 mF cm−2, which is 3.8 times that of Ni–P/TNAs (13.7 mF cm−2). In a two-electrode system with a Pt sheet as the anode, the Ni x Co y P/TNAs presented a bath voltage of 1.92 V at 100 mA cm−2, which is an improvment of 79% over that of 1.07 V at 10 mA cm−2.


2013 ◽  
Vol 78 (4) ◽  
pp. 549-554 ◽  
Author(s):  
Uros Lacnjevac

Composite Ni-MoO2 coatings were prepared and characterized with respect to their possible application as electrocatalysts for the hydrogen evolution reaction (HER) in alkaline solution. The composites were electrodeposited onto Ni meshes from an ammonium chloride Ni solution with suspended MoO2 particles in simulated industrial conditions for production of commercial cathodes. The influence of the concentration of MoO2 particles in the solution and deposition current density on the morphology, chemical and phase composition of obtained coatings was investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Catalytic activity for the HER of the coatings was examined by polarization measurements in a 32 wt. % NaOH solution at 90?C and compared to the activity of the commercial De Nora?s cathode (DN). It was shown that the most active Ni-MoO2 coating exhibits better polarization characteristics for the HER than the DN cathode. The mechanism of the HER on the specified Ni-MoO2 coating was investigated in 8 mol dm-3 NaOH at 30?C by means of steady-state polarization measurements and an electrochemical impedance spectroscopy (EIS) method. Based on the theoretical interpretation of the experimental data, rate constants of the three individual steps of the HER were determined and the source of catalytic activity of the coating was elucidated.


Sign in / Sign up

Export Citation Format

Share Document