Facile Synthesis of Ni-MgO/CNT Nanocomposite for Hydrogen Evolution Reaction

Abstract

In this study, the pristine MgO, MgO/CNT and Ni-MgO/CNT nanocomposites were processed using the impregnation and chemical vapor deposition methods and analyzed for hydrogen evolution reaction (HER) using the electrochemical water splitting process. Furthermore, the effect of nickel on the deposited carbon was systematically elaborated in this study. The highly conductive carbon nanotubes (CNTs) deposited on the metal surface of the Ni-MgO nanocomposite heterostructure provides a robust stability and superior electrocatalytic activity. The optimized Ni-MgO/CNT nanocomposite exhibited hierarchical, helical-shaped carbon nanotubes adorned on the surface of the Ni-MgO flakes, forming a hybrid metal–carbon network structure. The catalytic HER was carried out in a 1M alkaline KOH electrolyte, and the optimized Ni-MgO/CNT nanocomposite achieved a low (117 mV) overpotential value (ɳ) at 10 mA cm−2 and needed a low (116 mV/dec) Tafel value, denotes the Volmer–Heyrovsky pathway. Also, the high electrochemical active surface area (ECSA) value of the Ni-MgO/CNT nanocomposite attained 515 cm2, which is favorable for the generation of abundant electroactive species, and the prepared electrocatalyst durability was also performed using a chronoamperometry test for the prolonged duration of 20 h at 10 mA cm−2 and exhibited good stability, with a 72% retention. Hence, the obtained results demonstrate that the optimized Ni-MgO/CNT nanocomposite is a highly active and cost-effective electrocatalyst for hydrogen energy production.

Efficient Zinc Vanadate Homojunction with Cadmium Nanostructures for Photocatalytic Water Splitting and Hydrogen Evolution

“…The results obtained are given in Figure 9 b. As the irradiation time increases, owing to photoabsorption, the material reaction results in the generation of a higher number of electron–hole pairs, which results in higher H 2 production efficiency [ 9 ].…”

“…The electrons in the conduction band react with protons generated in the oxidation process and reduce them to hydrogen gas. The plausible mechanism for PC H 2 production over CdV/ZnV can be represented by Equations ( 6)- (9).…”

“…Various methods like the electrolysis of water, biomass gasification, fermentation, and steam reforming produce hydrogen and each has its own disadvantages [ 1 , 2 , 3 ]. The production of hydrogen by photocatalysis has been identified as one of the more effective and greener approaches for the proper usage of solar energy [ 3 , 8 , 9 ]. The products obtained by this method are environmentally friendly, carbon-free, and have a high calorific value.…”

Influence of Power Fluctuation on Ni-Based Electrode Degradation and Hydrogen Evolution Reaction Performance in Alkaline Water Splitting: Probing the Effect of Renewable Energy on Water Electrolysis

“…HER catalysts based on precious metals, such as platinum, are highly robust but suffer from high costs and low abundance [12,13]. Fortunately, nickel, as an abundant non-precious metal on Earth, exhibits excellent corrosion resistance and stability in alkaline electrolytes [14]. Research suggests that nickel ranks just below platinum group metals in hydrogen adsorption of Gibbs free energy, indicating its potential for reversible interconversion of H 2 O to hydrogen at low thermodynamic potentials with high efficiency and activity [9,11,15].…”