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

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• 作者：Xingxing Yu ; Tianyi Hua ; Xiang Liu ; Zhiping Yan ; Peng Xu ; Pingwu Du
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：September 10, 2014
• 年：2014
• 卷：6
• 期：17
• 页码：15395-15402
• 全文大小：475K
• ISSN：1944-8252

文摘

Herein, we report electrodeposited nickel-based thin film (NiO_x) 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 (鈭?.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 NiO_x-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%.

Keywords:

electrocatalyst; oxygen evolution; hydrogen production; water splitting; nickel; bifunctional