Dual-Doped Nickel Sulfide for Electro-Upgrading Polyethylene Terephthalate into Valuable Chemicals and Hydrogen Fuel

• Published in: Nano-micro letters Vol. 15; no. 1; pp. 210 - 15
• Main Authors: Chen, Zhijie, Zheng, Renji, Bao, Teng, Ma, Tianyi, Wei, Wei, Shen, Yansong, Ni, Bing-Jie
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01-12-2023; Springer Nature B.V; SpringerOpen
• Subjects: Catalysts; d Band centre; Dopants; Doping; Efficiency; Electro-upcycling; Electrocatalysts; Electrolysis; Energy Conversion and Storage; Engineering; Ethylene glycol; Heterostructures; Hydrogen; Hydrogen energy; Hydrogen fuels; Hydrogen production; Hydrolysates; Monomers; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Nickel sulfide; Organic waste upcycling; Oxidation; Polyethylene terephthalate; Reconstruction; Structural reconstruction; Waste management; Hydrogen energy; Structural reconstruction; Organic waste upcycling; d Band centre; Electro-upcycling
• ISSN: 2311-6706; 2150-5551; 2150-5551
• DOI: 10.1007/s40820-023-01181-8

Highlights
Co and Cl co-doped NiS is an efficient bifunctional electrocatalyst for converting plastic waste into formate and hydrogen with high efficiency and selectivity
Dopants regulate the electronic property and accelerate structural reconstruction of NiS for the core ethylene glycol (PET monomer) oxidation reaction
PET hydrolysate electrolysis can produce hydrogen gas at an average rate of 50.26 mmol h
−1
at 1.7 V
Electro-upcycling of plastic waste into value-added chemicals/fuels is an attractive and sustainable way for plastic waste management. Recently, electrocatalytically converting polyethylene terephthalate (PET) into formate and hydrogen has aroused great interest, while developing low-cost catalysts with high efficiency and selectivity for the central ethylene glycol (PET monomer) oxidation reaction (EGOR) remains a challenge. Herein, a high-performance nickel sulfide catalyst for plastic waste electro-upcycling is designed by a cobalt and chloride co-doping strategy. Benefiting from the interconnected ultrathin nanosheet architecture, dual dopants induced up-shifting d band centre and facilitated in situ structural reconstruction, the Co and Cl co-doped Ni
3
S
2
(Co, Cl-NiS) outperforms the single-doped and undoped analogues for EGOR. The self-evolved sulfide@oxyhydroxide heterostructure catalyzes EG-to-formate conversion with high Faradic efficiency (> 92%) and selectivity (> 91%) at high current densities (> 400 mA cm
−2
). Besides producing formate, the bifunctional Co, Cl-NiS-assisted PET hydrolysate electrolyzer can achieve a high hydrogen production rate of 50.26 mmol h
−1
in 2 M KOH, at 1.7 V. This study not only demonstrates a dual-doping strategy to engineer cost-effective bifunctional catalysts for electrochemical conversion processes, but also provides a green and sustainable way for plastic waste upcycling and simultaneous energy-saving hydrogen production.