Hollow Ni/NiO/C composite derived from metal-organic frameworks as a high-efficiency electrocatalyst for the hydrogen evolution reaction

Abstract

Metal-organic frameworks (MOFs) constitute a class of crystalline porous materials employed in storage and energy conversion applications. MOFs possess characteristics that render them ideal in the preparation of electrocatalysts, and exhibit excellent performance for the hydrogen evolution reaction (HER). Herein, H–Ni/NiO/C catalysts were synthesized from a Ni-based MOF hollow structure via a two-step process involving carbonization and oxidation. Interestingly, the performance of the H–Ni/NiO/C catalyst was superior to those of H–Ni/C, H–NiO/C, and NH–Ni/NiO/C catalysts for the HER. Notably, H–Ni/NiO/C exhibited the best electrocatalytic activity for the HER, with a low overpotential of 87 mV for 10 mA cm−2 and a Tafel slope of 91.7 mV dec−1. The high performance is ascribed to the synergistic effect of the metal/metal oxide and hollow architecture, which is favorable for breaking the H–OH bond, forming hydrogen atoms, and enabling charge transport. These results indicate that the employed approach is promising for fabricating cost-effective catalysts for hydrogen production in alkaline media.

Boosting the electrocatalytic activity and stability of Ni/NiO toward the oxygen evolution reaction by coupling FeOOH nanosheets

“…22–24 Two peaks at 510 and 1060 cm −1 were seen for the Ni/NiO/TM sample, ascribed to characteristic peaks of NiO. 25 As for the FeOOH-5/Ni/NiO/TM sample, two weak peaks indicated by arrows proved the presence of FeOOH. In addition, compared to those of Ni/NiO/TM, the Raman peaks corresponding to NiO had an obvious shift, suggesting a strong interaction between FeOOH and NiO, which is conducive to water electrooxidation.…”

Enhanced hydrogen production via urea electrolysis over Ni-NiO electrodeposited on Ti mesh

“…To further identify whether there are other components in Ni-NiO/TM, Raman characterization of Ni-NiO/TM electrodeposited at −1.5 V was performed. As shown in figure 2(a), there are two peaks located at 510 and 1060 cm −1 , ascribing to one-phonon longitudinal optical (1P LO ) vibration and 2P LO second-order vibrational mode of Ni-O bond in NiO [28].…”

Advancements in two-dimensional covalent organic framework nanosheets for electrocatalytic energy conversion: current and future prospects

“…Considering the constraints posed by the limited conditions and low energy efficiency of renewable energy generation, the integration of catalysts has emerged as a promising solution to address these challenges and foster a sustainable energy future [7] . Significant advancements can be realized to enhance the efficiency and effectiveness of renewable energy conversion processes by leveraging catalytic properties, including those of transition metal dichalcogenides [8,9] , transition metal chalcogenides [10] , metal-organic frameworks (MOFs) [11] , and covalent organic frameworks (COFs) [12,13] . These materials provide a substantial active surface area owing to their high surface-to-volume ratio, which facilitates efficient interactions and enhances the catalytic performance.…”