Ultra-thin CoNi0.2P nanosheets for plastics and biomass participated hybrid water electrolysis

Abstract

Designing cost-efficient and active electrocatalysts are very crucial for their practical implementation in electrochemical energy conversion systems. Herein, a handy template-post phosphatization approach is adopted to achieve ultra-thin CoNi0.2P nanosheets attached to nickel foam (termed as CoNi0.2P-uNS/NF) nanohybrids. Profiting from ultra-thin construction and the optimization of electronic structure, CoNi0.2P-uNS/NF exhibits high electroactivity for hydrogen evolution reaction (HER), which only needs an overpotential of 43 mV to obtain the current density of 10 mA cm−2. Additionally, CoNi0.2P-uNS/NF also reveals prominent electroactivity for ethylene glycol oxidation reaction (EGOR) in an alkaline environment due to the surface electrochemical reconstruction. Additionally, CoNi0.2P-uNS/NF also reveals similar high electroactivity for glycerol and furfural derivatives oxidation reaction, revealing its potential as a composition-controlled platform catalyst. For practical application, CoNi0.2P-uNS/NF||CoNi0.2P-uNS/NF electrolyzer is assembled to directly electrolyze the hydrolysate of polyethylene terephthalate (i.e., the mixture of terephthalate and ethylene glycol) for the co-generation of formate and hydrogen, accompanying with lower integral electrolytic voltage (1.24 V) than traditional water splitting (1.53 V) at current density 50 mA cm−2. This work expands the territory for energy-saving co-generation of hydrogen and value-added chemical products.