Interface Engineering on Heterostructural Nanosheets for Efficient Electrocatalytic-Paired Upcycling of Waste Plastics and Nitrate

Developing a coelectrolysis system of the nitrate reduction reaction (NO3RR) and polyethylene terephthalate-derived ethylene glycol oxidation reaction (EGOR) is of great significance for the electrocatalytic-paired upcycling of waste plastics and nitrate wastewater. However, a huge challenge remains in the exploitation of highly active catalytic electrodes. Herein, electrochemical interface engineering is developed for the rational synthesis of Cu-modified CoCu layered double hydroxide heterostructural nanosheets on carbon cloth (Cu@CoCu LDH/CC). The membrane electrode assembly (MEA) NO3RR||EGOR electrolyzer confirms the promising performance of Cu@CoCu LDH/CC with maximum FEs of formate and NH3 (98.1%/98.6% at 1.3 V), a high yield of NH3 (0.793 mmol h–1 cm–2 at 1.6 V), and stability over 120 h at 1.3 V, which outperforms the other reported coelectrolysis systems. In situ spectroscopy reveals the favorable formation of key reaction intermediates and catalytic active species, while the theoretical calculations confirm the optimized electronic structure and energy barriers of both the NO3RR and EGOR by constructing a Cu@CoCu LDH heterostructure, leading to its high intrinsic activity. Our work offers a promising strategy to develop advanced electrodes for coelectrosynthesis of value-added chemicals from the upcycling of nitrate wastewater and waste plastics.