A stable and recyclable NiCo layered double hydroxide (LDH)/O-MWCNT electrocatalyst for efficient gaseous methanol and acetone degradation

Abstract

The release of volatile organic compounds (VOCs) from a plethora of sources has become of great concern and a significant threat to human health and environment. Among the various VOC removal methods, the catalytic electro-oxidation of VOCs might provide an effective and low-cost routine, especially based on the non-noble metal catalysts. In this study, exfoliated NiCo layered double hydroxide (ex-LDH) and oxidized multiwalled carbon nanotubes (O-MWCNTs) were fabricated; both materials exhibit good electrochemical activity and stability towards gaseous methanol and acetone degradation in alkaline media (2 M KOH), in terms of high current density and low current decay over 1000 s at 1.5 V vs. RHE. In addition, the synergistic effect of ex-LDH and O-MWCNTs contributed to a remarkable enhancement of the catalytic activity of the ex-LDH/O-MWCNT composite catalyst, e.g. 0.51 A mg⁻¹ for methanol and 0.36 A mg⁻¹ for acetone at 1.5 V vs. RHE. More importantly, almost 100% performance retention could be achieved via the electrolyte replacement and electrode refreshing after the long-term testing; combined with its high catalytic activity, the ex-LDH/O-MWCNT material could be a promising candidate for powerful and reusable application in gaseous VOC degradation.