Green recycling of waste poly(ethylene terephthalate) into Ni-MOF nanorod for simultaneous interfacial solar evaporation and photocatalytic degradation of organic pollutants

Abstract

Interfacial solar evaporation is regarded as the promising technology to mitigate freshwater scarcity. However, when polluted water is used, toxic pollutants might accumulate in the bulk water. Herein, we report the production of Ni-MOF nanorod from waste poly(ethylene terephthalate) and fabricate bifunctional Ni-MOF-based evaporators. Owing to high light absorption and photothermal conversion, low thermal coefficient, and vaporization enthalpy, it shows an exciting evaporation rate (2.25 kg m⁻² h⁻¹) with good flexibility/durability, rated as one of most advanced evaporators. Density functional theory and COMSOL results show that the combination of nickel-sites in Ni-MOF and local heat plays a crucial role in peroxymonosulfate activation to produce reactive species. Thereby, it exhibits the high degradation activity of tetracycline. In outdoor, the freshwater production reaches 5.54 kg m⁻² per day, and the tetracycline removal efficiency is 91%. This work provides a sustainable approach to produce solar evaporators capable of freshwater production and contaminant degradation.