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Converting poly(ethylene terephthalate) (PET) into metal–organic frameworks (MOFs) has emerged as a promising innovation for upcycling of waste plastics. However, previous solvothermal methods suffer from toxic solvent consumption, long reaction time, high pressure, and high temperature. Herein, a mechanochemical milling strategy was reported to transform waste PET into a series of MOFs with high yields. This strategy had the merits of solvent‐free conditions, ambient reaction temperature, short running time, and easy scale‐up for large‐scale production of MOFs. The as‐prepared MOFs exhibited definite crystal structure and porous morphology composed of agglomerated nanoparticles. It was proven that, under mechanochemical milling, PET was firstly decomposed into 1,4‐benzenedicarboxylate, which acted as linkers to coordinate with metal ions for forming fragments, followed by the gradual arrangement of fragments into MOFs. This work not only promotes high value‐added conversion of waste polyesters but also offers a new opportunity to produce MOFs in a green and scalable manner. [ABSTRACT FROM AUTHOR]

[Display omitted] • Semiconductive Co-MOF nanorod in large quantity is prepared from discarded PET. • Co-MOF/CNT evaporator realizes wastewater purification and freshwater production. • CNT owns good photothermal conversion ability and rises photocatalysis efficiency. • Localized solar heat and rich open Co site of Co-MOF promote the activation of PMS. • Evaporator shows an evaporation rate of 2.25 kg m−2h−1 with TC removal of 99.8 % Catalytic conversion of waste plastics into semiconductive metal–organic framework (MOF) kills two birds with one stone, since it not merely offers promising possibility to realize freshwater production and water decontamination through interfacial solar evaporation and photocatalysis, but also advances upcycling of waste plastics. Nevertheless, exploiting synergistic photothermal-photocatalysis materials from recycled plastics remains a challenge. Herein, we report a facile solvothermal method of waste poly(ethylene terephthalate) bottles for the massive production of Co-MOF nanorod and construct a dual-functional Co-MOF/carbon nanotube (CNT) solar evaporator integrated with advanced oxidation process for simultaneous wastewater purification and freshwater production. Firstly, we prove that the evaporator owns high sunlight absorption due to the presence of CNT, super-hydrophilicity, and low heat conductivity, which endow it with fine photothermal conversion capability and reduced vaporization enthalpy. Benefiting from the above advantages, Co-MOF/CNT evaporator displays a high evaporation rate of 2.25 kg m−2 h−1 under 1 kW m−2 illumination, when treating tetracycline (TC)-polluted water, along with good mechanical property, high flexibility, long-term stability, and high scalability. Secondly, based on the results of COMSOL and density functional theory calculation, the localized solar heat from CNT and rich open cobalt sites of Co-MOF nanorod are proved to play a synergistic effect in the activation of peroxymonosulfate to generate various oxidation reactive species. Thereby, the dual-functional evaporator achieves a superb TC degradation activity. Lastly, an outdoor device is designed for freshwater generation and catalytic decomposition of TC. The daily freshwater production amount is 4.5 kg m−2, and the TC degradation efficiency is 93.1%. This study not merely advances the upcycling waste plastics into useful products, but also offers a sustainable platform to wastewater purification via a waste-treating-waste strategy. [ABSTRACT FROM AUTHOR]

Integrating interfacial solar steam generation with advanced oxidation process (AOP) is regarded as a promising strategy for addressing energy and environmental issues. However, developing dual-functional evaporators well-integrated with synergistic photothermal-AOP catalysis properties remains challenging. Herein, we synthesize cobalt-based metal-organic framework (Co-CAT) and prepare dual-functional Co-CAT evaporators. Co-CAT is endowed with "all-in-one" functions, i.e., high specific surface area, effective light absorption, and high catalytic activity. Co-CAT exhibits superior sunlight absorption and photo-to-thermal conversion property. The large specific surface area and abundant micropore of Co-CAT facilitate water permeation and evaporation enthalpy reduction. COMSOL Multiphysics and density functional theory calculation results prove that Co2+ sites in Co-CAT and heat localization promote peroxymonosulfate activation. Consequently, it not only exhibits a high-water evaporation rate of 2.2 kg m−2 h−1, outperforming the-state-of-art evaporators, but also presents the notable tetracycline degradation efficiency (91.1 %). This work proposes an ingenious way to deal with freshwater shortage and water pollution. [Display omitted] • Co-CAT with "all-in-one" functions is prepared by a facile hydrothermal method. • Co-CAT evaporator realizes wastewater purification and freshwater production. • Co-CAT owns good photothermal conversion ability and rises AOP catalysis efficiency. • Localized solar heat and rich open Co sites of Co-CAT promote the activation of PMS. • Evaporator shows an evaporation rate of 2.2 kg m−2 h−1 with TC removal of 91.1 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bilayer evaporator composed of porous carbon and wood is facilely prepared. • The sea urchin-like carbon is obtained from controlled carbonization of Ni-MOFs. • Porous carbon and wood synergistically boost the solar evaporation performance. • The evaporator owns long-term stability and salt cleaning ability for desalination. Solar evaporation is considered as a hopeful technology for producing freshwater from non-potable water using inexhaustible solar energy. However, solar evaporators with high performance and good scalability are still urgently needed. Herein, a bilayer solar evaporator is prepared by facilely coating natural wood with carbon materials pyrolyzed from sea urchin-like metal–organic frameworks (MOFs). The carbon materials inherit the sea urchin-like morphology and grow bamboo-like carbon nanotubes wrapping Ni nanoparticles, which synergistically contribute to the efficient light trapping and thermal harvesting. Meanwhile, the doped nitrogen and oxygen enhance the hydrophilicity of carbon materials. In another aspect, wood not only provides abundant hydrophilic channels for sufficient water supply, but also reduces the water evaporation enthalpy by 26% through the hydrogen bonds between water and hydrophilic groups of wood. With the combined merits above, the bilayer solar evaporator achieves high sunlight absorption (98%), low thermal conductivity (0.17 W m−1 K−1), rapid water transport, and low vaporization enthalpy. Consequently, the solar evaporator exhibits a notable water evaporation rate of 2.07 kg m-2 h−1 under 1 Sun irradiation, surpassing that of reported MOFs or wood-based evaporators. Importantly, a large-scale solar desalination device is developed for outdoor experiments to obtain freshwater from seawater. The daily freshwater production amount per unit area (2.74 kg) meets the daily water consumption requirement of one adult. This work states the great potential of MOFs-derived carbons for efficient solar vapor generation and opens an avenue for application in energy storage and conversion. [ABSTRACT FROM AUTHOR]