Carbonized MOF-Coated Zero-Valent Cu Driving an Efficient Dual-Reaction-Center Fenton-like Water Treatment Process through Utilizing Pollutants and Natural Dissolved Oxygen

Abstract

Excessive consumption of resources and energy is inevitable in a classical Fenton reaction due to the demand for electron donors or electron acceptors (H2O2) and the existence of reaction rate-limiting steps. In this work, we propose an innovative strategy to solve this key scientific problem by utilizing the organic pollutants and the dissolved oxygen (DO) naturally present in the wastewater through a newly developed carbonized metal–organic framework-coated zero-valent Cu catalyst (ZVC@CMOF). It has been found that the formation of a C–O–Cu bond bridge on the catalyst induces electron polarization distribution to form a non-equilibrium surface with electron-rich or electron-poor microareas based on a series of characterization techniques. This typical non-equilibrium surface feature leads to excellent performance for pollutant conversion and a new interfacial reaction mechanism. Various types of refractory organic pollutants can be rapidly degraded in a few minutes in the ZVC@CMOF Fenton-like systems, accompanied by good stability and a wide pH adaptation range. The interfacial reaction processes are revealed by experimental analysis and theoretical calculations, in which pollutants and DO act as electron donors and electron acceptors in the electron-poor and electron-rich microareas, respectively, which greatly reduce the consumption of H2O2 and improve the reaction efficiency and catalytic performance for pollutant removal.