Electrolytic Synthesis of Ni-W-MWCNT Composite Coating for Alkaline Hydrogen Evolution Reaction
- PDF / 1,284,150 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 109 Downloads / 214 Views
JMEPEG https://doi.org/10.1007/s11665-018-3134-z
43 5
Electrolytic Synthesis of Ni-W-MWCNT Composite Coating for Alkaline Hydrogen Evolution Reaction Liju Elias and A. Chitharanjan Hegde
OF
2
(Submitted November 29, 2016; in revised form December 5, 2017)
87 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Nickel–tungsten multi-walled carbon nanotube (Ni-W-MWCNT) composite films were fabricated by an electrodeposition technique, and their electrocatalytic activity toward hydrogen evolution reaction (HER) was studied. Ni-W-MWCNT composite films with a homogeneous dispersion of MWCNTs were deposited from an optimal Ni-W plating bath containing functionalized MWCNTs, under galvanostatic condition. The presence of functionalized MWCNT was found to enhance the induced codeposition of the reluctant metal W and resulted in a W-rich composite coating with improved properties. The electrocatalytic behaviors of Ni-W-MWCNT composite coating toward HER were studied by cyclic voltammetry (CV) and chronopotentiometry techniques in 1.0 M KOH medium. Further, Tafel polarization and electrochemical impedance spectroscopy (EIS) studies were carried out to establish the kinetics of HER on the alloy and composite electrodes. The experimental results revealed that the addition of MWCNTs (having a diameter of around 10-15 nm) into the alloy plating bath has a significant effect on the electrocatalytic behavior of NiW alloy deposit. The Ni-W-MWCNT composite coating was found to show better HER activity than the conventional Ni-W alloy coating. The enhanced electrocatalytic activity of Ni-W-MWCNT composite coating is attributed to the MWCNT intersticed in the deposit matrix, evidenced by surface morphology, composition and phase structure of the coating through SEM, EDS and XRD analyses, respectively.
D
TE
Keywords
Ni-W-MWCNT composite coating, electrodeposition, electrocatalysis, HER
EC
24 25 27 26
PR O
6
1. Introduction
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
The growth of industry is heavily dependent on fossil fuels from its beginning (Ref 1, 2), whereas the ever-increasing worldwide energy crisis and environmental pollution problems call for the need to make the long foreseen idea of an abundant and renewable clean fuel, hydrogen, based economy to a present reality (Ref 3, 4). A substantial amount of research work is going on for the development of an economically viable method for the mass production of hydrogen. Among the various hydrogen production techniques, electrocatalytic hydrogen production offers a sustainable way to the utilization of cheap, abundant and renewable water as feedstock (Ref 5-7). But the large deviation in operating cell voltage of the commercial electrolyzers (1.8-2.0 V) from the theoretical value (1.23 V) limits its wide application (Ref 4, 6, 9). Only the less abundant and expensive platinum group metals are showing good catalytic efficiency with low overpotential (Ref 4, 8, 10). This limitation can be overcome to certain extent by the development of a low cost, non-noble electro
Data Loading...
