Nickel-Based Thin Film on Multiwalled Carbon Nanotubes as an Efficient Bifunctional Electrocatalyst for Water Splitting

Abstract

Herein, we report electrodeposited nickel-based thin film (NiOx) on multiwalled carbon nanotubes (MWCNTs) as a highly efficient bifunctional catalyst for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Under reductive conditions (-1.2 V vs Ag/AgCl), the hydrogen evolution catalyst (H2-NiO(x)) was facilely deposited on MWCNTs. The resulting film demonstrates good catalytic activity for hydrogen production in a near-neutral aqueous solution at low overpotential. When switched to oxidative conditions (+1.1 V vs Ag/AgCl), the amorphous H2-NiO(x) film onto MWCNTs can be transformed into another amorphous material (O2-NiO(x)) to efficiently catalyze OER. The NiO(x)-MWCNTs catalyst was further characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). The results show that the content of oxygen in the O2-NiO(x)-MWCNTs film is higher than that in the H2-NiO(x)-MWCNTs film. The NiOx-MWCNTs catalyst has good catalytic stability, and the film is reversible when the potentials are switched between the reductive conditions and oxidative conditions. The Faradaic efficiencies of hydrogen and oxygen production are >95%.

One‐Dimensional Earth‐Abundant Nanomaterials for Water‐Splitting Electrocatalysts

“…Nonetheless, the catalytic properties of these early works were still far from optimum. Later, using a similar synthetic approach, Yu et al demonstrated that by direct electrodepositing a Ni‐based bifunctional material on 1D multiwalled CNTs, the performance of the electrocatalytic activity was much improved 89. Spectroscopic studies revealed that the content of oxygen in the O 2 ‐NiO x ‐CNT film (i.e., the OER catalyst) was higher than that in the H 2 ‐NiO x ‐CNT film (i.e., the HER catalyst).…”

Pt nanoparticles/MoS2 nanosheets/carbon fibers as efficient catalyst for the hydrogen evolution reaction

“…However, their scarcity and high costs of Pt-group metals have hindered their wide applications. Recently, inorganic catalysts, such as MoS 2 , WS 2 and CoSe 2 , have drawn great attention due to their low costs, high chemical stability, and excellent catalytic properties in HER [8][9][10][11][12][13][14]. However, the catalytic activity of the above reported catalysts can't be compared with that of Pt-based electrocatalysts.…”

An electronic approach to minimising moisture-associated skin damage in ostomy patients

“…2) which can actively measure the pH and respond accordingly. The electrochemical control of processes that involve either the production of protons (H + ) or their consumption (and hence enable pH manipulation) have been successfully demonstrated in a number of electroanalytical [29,30] and electroporation systems [31][32][33][34] but the underpinning reactions are now being extensively researched in solar conversion and hydrogen fuel cell technologies [35][36][37][38][39][40][41]. Our contention is that these processes which, in principle, can lead to changes in pH profile at the electrode, could be harnessed to control the pH at the skin surface.…”